DEVELOPMENT OF THE SAPRC-07 CHEMICAL 

MECHANISM AND UPDATED OZONE 

REACTIVITY SCALES

Report to the California Air Resources Board

Contracts No. 03-318, 06-408, and 07-730

By

William P. L. Carter

Revised January 27, 2010

Center for Environmental Research and Technology

College of Engineering

University of California

Riverside, California 92521
ii

ABSTRACT

A completely updated version of the SAPRC-99 chemical mechanism, designated SAPRC-07, 

has been developed and is documented in this report. This includes a complete update of the rate 

constants and reactions based on current data and evaluations, reformulated and less parameterized 

aromatics mechanisms, a representation of chlorine chemistry, a reformulated method to represent peroxy 

reactions that is more appropriate for modeling secondary organic aerosol formation, and improved 

representations for many types of VOCs. This mechanism was evaluated against the result of ~2400 

environmental chamber experiments carried out in 11 different environmental chambers, including 

experiments to test mechanisms for over 120 types of VOCs. The performance of the mechanism in 

simulating the chamber data was comparable to SAPRC-99, with generally satisfactory results for most 

types of VOCs but some increases in biases in simulations of some mixture experiments. The mechanism 

was used to derive an update to the MIR and other ozone reactivity scales for over 1100 types of VOCs. 

The average changes in relative MIR values was about 10%, with >90% of the VOCs having changes less 

than 30%, but with larger changes for some types of VOCs, including halogenated compounds. 

Recommendations are given for future mechanism development research. 

The mechanism documentation includes some large tabulations that are being provided only in 

electronic form. Links to downloading these tabulations are available at http://www.cert.ucr.edu/~carter 

/SAPRC.

Note: This version of the report and the associated supplementary materials and files superceded 

those available previously at the above-referenced web site. The changes are summarized in Appendix E 

to this report.
iii

ACKNOWLEDGEMENTS AND DISCLAIMERS

This work was carried out at the College of Engineering Center for Environmental Research and 

Technology (CE-CERT) at the University of California at Riverside (UCR), with funding by the 

California Air Resources Board (CARB) primarily through contract number 03-318, with additional work 

carried out through Contracts 06-408 and 07-730. However, the contents of this report reflect only the 

opinions and conclusions of the author, and not CE-CERT, UCR, or the CARB.

The author wishes to thank Dr. Roger Atkinson of the Air Pollution Research Center at UCR for 

many helpful discussions concerning available kinetic and mechanistic data and atmospheric chemistry in 

general, and for partial support during the period of this project. The author also appreciates the patience 

of the staff of the Research Division of the CARB, particularly Dr. Dongmin Luo, regarding the delays in 

completing this project and their continuing support. Experiments for this project that were used in this 

mechanism evaluation were carried out primarily by Ms. Irina Malkina with assistance from Mr. Kurt 

Bumiller and other members of the CE-CERT Atmospheric Processes Laboratory staff, and their 

contributions are gratefully acknowledged. Finally, the author wishes to acknowledge the University of 

California Retirement System, which provided major support to the author during the completion of 

mechanism development and the preparation of this report.

When discussing materials whose mechanisms were evaluated, this report makes references to 

"Texanol", which is a trademark of Eastman Chemical Company, and "Exxol" and "Isopar", which are 

trademarks of ExxonMobil Chemical Company. Mention of trade names and commercial products does 

not constitute endorsement or recommendation for use.
iv

TABLE OF CONTENTS

EXECUTIVE SUMMARY .......................................................................................................................... 1

Background ............................................................................................................................................ 1

Accomplishments................................................................................................................................... 1

Results.................................................................................................................................................... 2

Recommendations.................................................................................................................................. 3

INTRODUCTION ........................................................................................................................................ 5

MECHANISM DOCUMENTATION .......................................................................................................... 8

Base Mechanism..................................................................................................................................... 8

Listing of Standard Base Mechanism and Summary of Changes.................................................... 8

Representation of Peroxy Radical Operators................................................................................. 13

Base Chlorine Mechanism............................................................................................................. 15

Representation of Organic Products .............................................................................................. 16

Mechanisms for Individual VOCs........................................................................................................ 17

Mechanism Generation and Estimation System ............................................................................ 17

Enhanced Capabilities for VOCs and Reactions..................................................................... 18

Support for Chlorine Reactions............................................................................................... 19

Updates to Rate Constants and Mechanisms........................................................................... 26

Adjusted Product Mechanisms................................................................................................ 28

Updated Aromatics Mechanisms................................................................................................... 31

Reactions of Alkylbenzenes with OH ..................................................................................... 33

Representation of Unsaturated Dicarbonyl Products............................................................... 42

Aromatic Ring Retaining Products.......................................................................................... 50

Non-Alkylbenzene Aromatics................................................................................................. 51

Reactions with Chlorine .......................................................................................................... 51

Mechanisms for Amines................................................................................................................ 55

Miscellaneous Assigned Mechanisms ........................................................................................... 57

Lumped Molecule Representations................................................................................................ 60

Lumped Mechanisms for Airshed Models........................................................................................... 61

Adjustable Parameter Mechanisms................................................................................................ 61

Fixed Parameter Mechanism.......................................................................................................... 61

Emissions Assignments ................................................................................................................. 65

MECHANISM EVALUATION ................................................................................................................. 67

Methods................................................................................................................................................ 71

Data Presented...................................................................................................................................... 77

Results.................................................................................................................................................. 79

Results for Chamber Characterization Experiments...................................................................... 79

Results for Mechanism Evaluation Experiments........................................................................... 79

Overall Performance in Simulating Entire Dataset ................................................................. 79

Evaluation Experiments for Individual VOCs ........................................................................ 80

Evaluation Experiments for Mixtures ..................................................................................... 92

Mechanism Performance for Direct Reactivity Experiments...................................................... 100

UPDATED REACTIVITY SCALES ....................................................................................................... 101

Methods.............................................................................................................................................. 101

Results................................................................................................................................................ 103

Predicted Ozone Formation in the Scenarios............................................................................... 103
TABLE OF CONTENTS (continued)

v

Updated Ozone Reactivity Scales................................................................................................ 105

Updated Uncertainty Estimates.................................................................................................... 106

SUMMARY AND RECOMMENDATIONS........................................................................................... 109

Summary of Project Accomplishments.............................................................................................. 109

Recommendations.............................................................................................................................. 114

REFERENCES ......................................................................................................................................... 121

APPENDIX A. GENERAL MECHANISM LISTING TABLES ............................................................ 135

APPENDIX B. MECHANISM AND REACTIVITY LISTINGS FOR INDIVIDUAL VOCS .............. 176

APPENDIX C. MECHANISM EVALUATION TABULATIONS AND PLOTS .................................. 270

APPENDIX D. SUPPLEMENTARY MATERIAL AVAILABLE ......................................................... 376

APPENDIX E. CHANGE LOG................................................................................................................ 377
vi

LIST OF TABLES

Table 1. Reactions where the rate constants or photolysis rates changed by more than 5% or 

that were added or removed in the standard base mechanism relative to SAPRC-99. .......... 11

Table 2. Products formed in the reactions of the chemical operators used to represent peroxy 

radical reactions in the SAPRC-07 mechanism. .................................................................... 14

Table 3. Group additivity parameters used for estimating rate constants for abstraction 

reactions by OH and NO3 radicals and by Cl atoms. ............................................................. 20

Table 4. Rate constants for reactions with chlorine atoms for organic compounds used to 

derive parameters for group-additivity estimates................................................................... 24

Table 5. Group additivity rate constants and factors used for estimating rates of addition of Cl 

atoms to double bonds............................................................................................................ 26

Table 6. Branching ratio assignments for chlorine-substituted alkoxy radicals made to 

generate mechanisms for the reactions of chlorine with representative alkenes.................... 27

Table 7. Assigned mechanisms for Crigiee Biradicals used for deriving mechanisms for 

reactions of O3 with alkenes................................................................................................... 29

Table 8. Compounds whose Averaged Conditions MIR reactivities changed by more than 

20% when adjustable product mechanisms were employed. ................................................. 31

Table 9. Measured or estimated yields of known products for benzene and methylbenzene 

reactions that were incorporated in the SAPRC-07 aromatics mechanisms.......................... 34

Table 10. Rate constants and assumptions used to estimate fractions of reaction of on and off 

the aromatic ring for the reactions of OH with aromatic compounds or groups of 

compounds for which mechanistic parameters have been derived. ....................................... 40

Table 11. Model species used to represent non-nitrate products from the reactions of OH 

radicals at aromatic rings for various types of ring structures. Yields are normalized 

to OH ring addition only, excluding nitrate formation........................................................... 43

Table 12. Estimated yields for unsaturated dicarbonyl products in the OH reactions of the 

methylbenzenes for which -dicarbonyl yield data are available.......................................... 44

Table 13. Mechanism estimation assignments made for representative unsaturated dicarbonyl 

compounds for the purpose of generating mechanisms for the aromatic 

fragmentation product model species AFG1-3. ..................................................................... 46

Table 14. Discussion of mechanisms for the non-alkylbenzene aromatic compounds that for 

which mechanistic assignments have been derived. The rate constants and additional 

documentation are given in Table B-4 and the reactions are given in Table B-2 in 

Appendix B. ........................................................................................................................... 51

Table 15. Assignments made for alkoxy radical intermediates predicted to be formed in the 

photooxidation mechanisms of the amines. ........................................................................... 56

Table 16. Discussion of mechanisms for miscellaneous compounds that were not derived using 

the procedures discussed previously in this report. The rate constants, reactions, and 

additional documentation are given in Table B-2, and Table B-4 through Table B-6 

in Appendix B. ....................................................................................................................... 58
LIST OF TABLES (continued)

vii

Table 17. List of model species used in the lumped mechanism for airshed models for 

representing the various types of emitted VOCs.................................................................... 62

Table 18. Compounds and weighting factors used to derive the parameters for the ALK and 

ARO model species in the fixed parameter mechanism for airshed models.......................... 64

Table 19. Compounds and weighting factors used to derive the parameters for the OLE and 

TERP model species in the fixed parameter mechanism for airshed models ........................ 65

Table 20. Summary of environmental chambers whose data were used for mechanism 

evaluation............................................................................................................................... 68

Table 21. Summary of types of experiments used for mechanism evaluation. ....................................... 70

Table 22. Chamber wall effect and background characterization parameters used in the 

environmental chamber model simulations for mechanism evaluation. ................................ 73

Table 23. Summary of mechanism evaluation results using chamber experiments for individual 

compounds and mixtures. ...................................................................................................... 84

Table 24. Scenarios used for reactivity assessment, with updated calculated maximum O3, 

Integrated OH, and MIR, MOIR, and EBIR NOx inputs. .................................................... 102

Table 25. List of compounds and mixtures whose reactivities in the MIR scale changed by 

more than 30%. .................................................................................................................... 107

Table A-1. List of model species used in the standard base SAPRC-07 mechanism. The lumped 

model species added for the fixed parameter lumped mechanism for airshed models 

are also listed........................................................................................................................ 135

Table A-2. Listing of reactions and rate parameters in the base SAPRC-07 mechanism. ..................... 139

Table A-3. Absorption cross-sections and quantum yields for the all photolysis reactions in the 

base mechanism. (Available in electronic form only).......................................................... 162

Table A-4. List of model species used in the base chlorine SAPRC-07 mechanism. ............................ 162

Table A-5. Listing of reactions and rate parameters added to represent the reactions of chlorine 

species in the SAPRC-07 mechanism. ................................................................................. 163

Table A-6. Absorption cross-sections and quantum yields for the all photolysis reactions added 

for the chlorine chemistry mechanism. ................................................................................ 169

Table A-7. Listing of reactions and rate parameters used for the lumped model species in the 

fixed parameter version of the lumped SAPRC-07 mechanism. ......................................... 172

Table B-1. Listing of detailed model species, their representation in the model, and calculated 

atmospheric reactivity values in various reactivity scales ................................................... 177

Table B-2. Listing of mechanisms for all VOCs for which mechanism assignments have been 

derived. (Available in electronic form only)........................................................................ 209

Table B-3. Listing of adjusted product mechanisms for all VOCs for which such mechanisms 

have been derived. (Available in electronic form only)....................................................... 209
LIST OF TABLES (continued)

viii

Table B-4. Listing of compounds for which mechanisms have been derived. 1. OH radical rate 

constants at 300oK, mechanism types, and structures used for compounds with 

generated mechanisms. ........................................................................................................ 210

Table B-5. Listing of compounds for which mechanisms have been derived. 2. Rate constants 

for reactions with O3, NO3, and O3P at 300oK, where applicable. ....................................... 235

Table B-6. Listing of compounds for which mechanisms have been derived. 3. Absorption 

cross-sections, quantum yields, and mechanisms for photolysis reactions, where 

applicable. ............................................................................................................................ 241

Table B-7. Listing of compounds for which mechanisms have been derived. 4. Rate constants 

and mechanisms for reactions with chlorine atoms, where used. ........................................ 244

Table B-8. Absorption cross sections used for the photolysis reactions for represented 

photoreactive VOCs that are not in the base mechanism..................................................... 252

Table B-9. Lumped molecule representations used in the SAPRC-07 mechanism. .............................. 256

Table B-10. Listing of components of complex mixtures for which atmospheric reactivities have 

been calculated. (Available in electronic form only)........................................................... 269

Table B-11. Assignments of explicitly represented compounds to lumped model species in the 

fixed parameter mechanism. (Available in electronic form only)........................................ 269

Table C-1. List of environmental chamber experiments used in the mechanism evaluation. . 

(Available in electronic form only)...................................................................................... 270
ix

LIST OF FIGURES

Figure 1. Effect of using the adjustable product mechanisms vs. the standard fixed product 

mechanisms on incremental reactivities in the "Averaged Conditions" MIR scale for 

those VOCs for which adjustable product mechanisms could be derived. ............................ 31

Figure 2. Reactions of the OH - aromatic ring adduct that are assumed in the current 

mechanism. The example shown is for benzene, but analogous reactions are 

assumed for the alkylbenzenes............................................................................................... 37

Figure 3. Nitrate yield factors used for estimating aromatic oxidation mechanisms.............................. 39

Figure 4. Action spectra for photodecompositions of 2-buene-1,4-dial, 4-oxo-2-penteneal and 

used for the model species AFG1 and AFG2......................................................................... 50

Figure 5. Distribution of ([O3]-[NO]) model errors for the radical source characterization 

experiments. ........................................................................................................................... 81

Figure 6. Distribution of O3 model errors for the NOx offgasing characterization experiments ............ 82

Figure 7. Distributions of ([O3]-[NO]) model errors for all of the single VOC - NOx and 

mixture - NOx experiments used in the mechanism evaluation. ............................................ 83

Figure 8. Experimental and calculated effects of CO addition in representative toluene and 

m-xylene NOx experiments carried out in the UCR EPA chamber. ...................................... 91

Figure 9. Plots of model errors in simulations of miscellaneous mixture - NOx experiments 

carried out in various chambers. ............................................................................................ 94

Figure 10. Plots of model errors in simulations of miscellaneous surrogate - NOx experiments 

carried out in various UCR chambers and in the TVA chamber. .......................................... 95

Figure 11. Plots of model errors in simulations of surrogate - NOx experiments carried out in 

the UNC chamber................................................................................................................... 96

Figure 12. Plots of model errors in simulations of the standard base case surrogate - NOx

irradiations carried out in conjunction with the incremental reactivity experiments in 

the ETC and DTC (blacklight), and CTC and XTC (arc light) chambers............................. 97

Figure 13. Plots of model errors in simulations of the surrogate - NOx experiments carried out 

in the UCR EPA chamber. ..................................................................................................... 98

Figure 14. Plots of model errors in simulations of 6-hour ([O3]-[NO]) against initial ROG 

surrogate /NOx ratio. .............................................................................................................. 99

Figure 15. Model performance in simulating the direct reactivity data of Carter and Malkina 

(2002)................................................................................................................................... 100

Figure 16. Plots of maximum O3 concentrations calculated for the various scenarios used for 

reactivity assessment against the initial ROG levels in the scenarios.................................. 104

Figure 17. Change in maximum O3 concentrations in the scenarios used for reactivity 

assessment, calculated using SAPRC-07 compared to SAPRC-99. .................................... 105

Figure 18. Plots of incremental reactivities in the MIR scale computed using the updated 

mechanism against those reported previously by Carter (2003a). ....................................... 106
LIST OF FIGURES (continued)

x

Figure C-1. Plots of experimental and calculated environmental chamber reactivity results for 

carbon monoxide.................................................................................................................. 271

Figure C-2. Plots of experimental and calculated environmental chamber reactivity results for 

ethane and propane............................................................................................................... 272

Figure C-3. Plots of experimental and calculated environmental chamber reactivity results for nbutane................................................................................................................................... 273

Figure C-4. Plots of experimental and calculated environmental chamber reactivity results for nhexane and the Surg-3 MIR1 experiments for n-octane. ..................................................... 274

Figure C-5. Plots of experimental and calculated environmental chamber reactivity results for noctane (excluding the Surg-3 MIR1 experiments, which are on Figure C-4). ..................... 275

Figure C-6. Plots of experimental and calculated environmental chamber reactivity results for ndodecane............................................................................................................................... 276

Figure C-7. Plots of experimental and calculated environmental chamber reactivity results for ntetradecane ........................................................................................................................... 277

Figure C-8. Plots of experimental and calculated environmental chamber reactivity results for npentadecane and n-hexadecane. ........................................................................................... 278

Figure C-9. Plots of experimental and calculated environmental chamber reactivity results for 

isobutane, 2,2,4-trimethyl pentane, and 2,6-dimethyl octane. ............................................. 279

Figure C-10.Plots of experimental and calculated environmental chamber reactivity results for 2-

methyl nonane and 3,4-diethyl hexane................................................................................. 280

Figure C-11.Plots of experimental and calculated environmental chamber reactivity results for 

cyclohexane and hexyl cyclohexane. ................................................................................... 281

Figure C-12.Plots of experimental and calculated environmental chamber reactivity results for 

octyl cyclohexane................................................................................................................. 282

Figure C-13.Plots of model errors in simulations of the ethene - NOx environmental chamber 

experiments. ......................................................................................................................... 283

Figure C-14.Plots of experimental and calculated environmental chamber reactivity results for 

ethene. .................................................................................................................................. 284

Figure C-15.Plots of model errors in simulations of the propene - NOx environmental chamber 

experiments. ......................................................................................................................... 285

Figure C-16.Plots of experimental and calculated environmental chamber reactivity results for 

propene................................................................................................................................. 286

Figure C-17.Plots of model errors in simulations of the 1-buteme and 1-hexene - NOx

environmental chamber experiments. .................................................................................. 287

Figure C-18.Plots of model errors in simulations of the trans-2-butene and isobutene - NOx

environmental chamber experiments. .................................................................................. 288

Figure C-19.Plots of experimental and calculated environmental chamber reactivity results for 

isobutene and trans-2-butene................................................................................................ 289
LIST OF FIGURES (continued)

xi

Figure C-20.Plots of model errors in simulations of the isoprene - NOx environmental chamber 

experiments. ......................................................................................................................... 290

Figure C-21.Plots of experimental and calculated environmental chamber reactivity results for 

isoprene ................................................................................................................................ 291

Figure C-22.Plots of model errors in simulations of the terpene - NOx environmental chamber 

experiments. ......................................................................................................................... 292

Figure C-23.Plots of experimental and calculated environmental chamber reactivity results for -

and -pinene and d-limonene............................................................................................... 293

Figure C-24.Plots of experimental and calculated environmental chamber reactivity results for 

cyclohexene.......................................................................................................................... 294

Figure C-25.Plots of experimental and calculated environmental chamber reactivity results for 

styrene.................................................................................................................................. 294

Figure C-26.Plots of model errors in simulations of the benzene and benzene + CO - NOx

environmental chamber experiments. .................................................................................. 295

Figure C-27.Plots of experimental and calculated environmental chamber reactivity results for 

benzene................................................................................................................................. 296

Figure C-28.Plots of model errors in simulations of the toluene and toluene + CO - NOx

environmental chamber experiments. .................................................................................. 297

Figure C-29.Plots of model errors in simulations of the ethylbenzene - NOx environmental 

chamber experiments. .......................................................................................................... 298

Figure C-30.Plots of experimental and calculated environmental chamber reactivity results for 

toluene and ethylbenzene..................................................................................................... 299

Figure C-31.Plots of model errors in simulations of the m-xylene and m-xylene + CO - NOx

environmental chamber experiments. .................................................................................. 300

Figure C-32.Plots of model errors in simulations of the o-xylene - NOx environmental chamber 

experiments. ......................................................................................................................... 301

Figure C-33.Plots of model errors in simulations of the p-xylene - NOx environmental chamber 

experiments. ......................................................................................................................... 302

Figure C-34.Plots of experimental and calculated environmental chamber reactivity results for mxylene (additional experiments shown on Figure C-35). ..................................................... 303

Figure C-35.Plots of experimental and calculated environmental chamber reactivity results for mxylene (with variable surrogate conditions), o-xylene, and p-xylene. ................................. 304

Figure C-36.Plots of model errors in simulations of the 1,2,3-trimethylbenzene - NOx

environmental chamber experiments. .................................................................................. 305

Figure C-37.Plots of model errors in simulations of the 1,2,4-trimethylbenzene - NOx

environmental chamber experiments. .................................................................................. 306

Figure C-38.Plots of model errors in simulations of the 1,3,5-trimethylbenzene and 1,3,5-

trimethylbenzene + CO - NOx environmental chamber experiments................................... 307

Figure C-39.Plots of experimental and calculated environmental chamber reactivity results for 

1,2,3-, 1,2,4- and 1,3,4-trimethylbenzenes........................................................................... 308
LIST OF FIGURES (continued)

xii

Figure C-40.Plots of model errors in simulations of the naphthalene, 2,3-dimethylnaphthalene, 

and tetralin - NOx environmental chamber experiments...................................................... 309

Figure C-41.Plots of model errors in simulations of the acetylene - NOx environmental chamber 

experiments. ......................................................................................................................... 310

Figure C-42.Plots of experimental and calculated environmental chamber reactivity results for 

acetylene............................................................................................................................... 311

Figure C-43.Plots of experimental and calculated environmental chamber reactivity results for 

methanol and ethanol. .......................................................................................................... 312

Figure C-44.Plots of experimental and calculated environmental chamber reactivity results for 

isopropyl alcohol.................................................................................................................. 313

Figure C-45.Plots of experimental and calculated environmental chamber reactivity results for tbutyl alcohol......................................................................................................................... 314

Figure C-46.Plots of experimental and calculated environmental chamber reactivity results for 1-, 

2-, and 3-octanol. ................................................................................................................. 315

Figure C-47.Plots of experimental and calculated environmental chamber reactivity results for 

ethylene glycol. .................................................................................................................... 316

Figure C-48.Plots of experimental and calculated environmental chamber reactivity results for 

propylene glycol................................................................................................................... 317

Figure C-49.Plots of experimental and calculated environmental chamber reactivity results for 

dimethyl ether and diethyl ether........................................................................................... 318

Figure C-50.Plots of experimental and calculated environmental chamber reactivity results for 

methyl t-butyl ether.............................................................................................................. 319

Figure C-51.Plots of experimental and calculated environmental chamber reactivity results for 1-

methoxy-2-propanol............................................................................................................. 320

Figure C-52.Plots of experimental and calculated environmental chamber reactivity results for 2-

ethoxyethanol and 2-(2-ethoxyethoxy) ethanol (DGEE). .................................................... 321

Figure C-53.Plots of experimental and calculated environmental chamber reactivity results for 2-

butoxyethanol....................................................................................................................... 322

Figure C-54.Plots of experimental and calculated environmental chamber reactivity results for 2-

(2-butoxyethoxy)-ethanol..................................................................................................... 323

Figure C-55.Plots of experimental and calculated environmental chamber reactivity results for 

methyl acetate. ..................................................................................................................... 324

Figure C-56.Plots of experimental and calculated environmental chamber reactivity results for 

ethyl acetate.......................................................................................................................... 325

Figure C-57.Plots of experimental and calculated environmental chamber reactivity results for 

isopropyl and t-butyl acetates............................................................................................... 326

Figure C-58.Plots of experimental and calculated environmental chamber reactivity results for 

methyl isobutyrate................................................................................................................ 327

Figure C-59.Plots of experimental and calculated environmental chamber reactivity results for 

methyl pivalate..................................................................................................................... 328
LIST OF FIGURES (continued)

xiii

Figure C-60.Plots of experimental and calculated environmental chamber reactivity results for nbutyl acetate. ........................................................................................................................ 329

Figure C-61.Plots of experimental and calculated environmental chamber reactivity results for 

dimethyl carbonate and methyl isopropyl carbonate............................................................ 330

Figure C-62.Plots of experimental and calculated environmental chamber reactivity results for 

propylene carbonate. ............................................................................................................ 331

Figure C-63.Plots of experimental and calculated environmental chamber reactivity results for 1-

methoxy-2-propyl acetate..................................................................................................... 332

Figure C-64.Plots of experimental and calculated environmental chamber reactivity results for 

dimethyl succinate and dimethyl glutarate........................................................................... 333

Figure C-65.Plots of experimental and calculated environmental chamber reactivity results for 

the Texanol® isomers. ......................................................................................................... 334

Figure C-66.Plots of model errors in simulations of the furan - NOx environmental chamber 

experiments. ......................................................................................................................... 335

Figure C-67.Plots of model errors in simulations of the methyl furan - NOx environmental 

chamber experiments. .......................................................................................................... 336

Figure C-68.Plots of model errors in simulations of the benzyl alcohol and benzyl alcohol + CO -

NOx environmental chamber experiments. .......................................................................... 337

Figure C-69.Plots of experimental and calculated environmental chamber reactivity results for 

benzyl alcohol. ..................................................................................................................... 338

Figure C-70.Plots of model errors in simulations of the formaldehyde - NOx environmental 

chamber experiments. .......................................................................................................... 339

Figure C-71.Plots of experimental and calculated environmental chamber reactivity results for 

formaldehyde. ...................................................................................................................... 340

Figure C-72.Plots of model errors in simulations of the acetaldehyde - NOx environmental 

chamber experiments. .......................................................................................................... 341

Figure C-73.Plots of experimental and calculated environmental chamber reactivity results for 

acetaldehyde......................................................................................................................... 342

Figure C-74.Plots of model errors in simulations of the acrolein and methacrolein (MA) - NOx

environmental chamber experiments. .................................................................................. 343

Figure C-75.Plots of experimental and calculated environmental chamber reactivity results for 

benzaldehyde........................................................................................................................ 344

Figure C-76.Plots of model errors in simulations of the acetone - NOx environmental chamber 

experiments. ......................................................................................................................... 345

Figure C-77.Plots of experimental and calculated environmental chamber reactivity results for 

acetone. ................................................................................................................................ 346

Figure C-78.Plots of model errors in simulations of the methyl ethyl ketone (MEK), 2-pentanone 

(MPK) and 2-heptanone - NOx environmental chamber experiments. ................................ 347

Figure C-79.Plots of experimental and calculated environmental chamber reactivity results for 

methyl ethyl ketone.............................................................................................................. 348
LIST OF FIGURES (continued)

xiv

Figure C-80.Plots of experimental and calculated environmental chamber reactivity results for 2-

pentanone. ............................................................................................................................ 349

Figure C-81.Plots of experimental and calculated environmental chamber reactivity results for 4-

methyl-2-pentanone and 2-heptanone.................................................................................. 350

Figure C-82.Plots of experimental and calculated environmental chamber reactivity results for 

cyclohexanone...................................................................................................................... 351

Figure C-83.Plots of model errors in simulations of the methyl vinyl ketone - NOx environmental 

chamber experiments. .......................................................................................................... 352

Figure C-84.Plots of experimental and calculated ([O3]-[NO]), cresol, and PAN concentrations 

in the cresol - NOx environmental chamber experiments..................................................... 353

Figure C-85.Plots of experimental and calculated environmental chamber reactivity results for mcresol.................................................................................................................................... 353

Figure C-86.Plots of experimental and calculated environmental chamber reactivity results for 

para toluene isocyanate. ....................................................................................................... 354

Figure C-87.Plots of experimental and calculated environmental chamber reactivity results for 

2,4-toluene diisocyanate (TDI1) and 2,6-toluene diisocyanate (TDI2). .............................. 355

Figure C-88.Plots of experimental and calculated environmental chamber reactivity results for nmethyl-2-pyrrolidone. .......................................................................................................... 356

Figure C-89.Plots of experimental and calculated environmental chamber reactivity results for npropyl bromide and n-butyl bromide. .................................................................................. 357

Figure C-90.Plots of experimental and calculated environmental chamber reactivity results for 

trichloroethylene. ................................................................................................................. 358

Figure C-91.Plots of model errors in simulations of the 1,3-dichloropropene and 1,3-

dichloropropene + n-butane - NOx environmental chamber experiments............................ 359

Figure C-92.Plots of experimental and calculated environmental chamber reactivity results for 

the 1,3-dichloropropenes...................................................................................................... 360

Figure C-93.Plots of experimental and calculated environmental chamber reactivity results for 2-

(chloromethyl)-3-chloro-propene......................................................................................... 360

Figure C-94 Plots of model errors in simulations of the chloropicrin (CP) – alkane - NOx and the 

chlorine + alkane - NOx experiments. .................................................................................. 361

Figure C-95.Plots of experimental and calculated environmental chamber reactivity results for 

chloropicrin. ......................................................................................................................... 362

Figure C-96.Plots of experimental and calculated environmental chamber reactivity results for 

chlorine. Note that chlorine was added to the "base case" experiment after four hours 

of irradiation......................................................................................................................... 362

Figure C-97.Plots of experimental and calculated environmental chamber reactivity results for 

hexamethyldisiloxane, d4 cyclosiloxane, and hydroxymethyldisiloxane. ........................... 363

Figure C-98.Plots of experimental and calculated environmental chamber reactivity results for 

carbon disulfide and methyl isothiocyanate......................................................................... 364
LIST OF FIGURES (continued)

xv

Figure C-99.Plots of experimental and calculated O3, NO, DMSO and formaldehyde in the 

dimethyl sulfoxide - NOx environmental chamber experiments.......................................... 365

Figure C-100. Plots of experimental and calculated environmental chamber reactivity results 

for dimethyl sulfoxide.......................................................................................................... 365

Figure C-101. Plots of experimental and calculated environmental chamber reactivity results 

for s-ethyl dipropylthiocarbamate (EPTC)........................................................................... 366

Figure C-102. Plots of experimental and calculated environmental chamber reactivity results 

for the mineral spirits samples studied for Safety-Kleen (Carter et al, 1997e).................... 367

Figure C-103. Plots of experimental and calculated environmental chamber reactivity results 

for Exxon Exxol® D95 Fluid and Exxon Isopar® M Fluid studied for ExxonMobil 

(Carter et al, 2000e). ............................................................................................................ 368

Figure C-104. Plots of experimental and calculated environmental chamber reactivity results 

for oxo-decyl Acetate fluid studied for ExxonMobil (Carter et al, 2000e).......................... 369

Figure C-105. Plots of experimental and calculated environmental chamber reactivity results 

for VMP Naphtha sample studied by Carter and Malkina (2005) and the Kerosene 

sample studied by Carter and Malkina (2007). .................................................................... 370

Figure C-106. Plots of experimental and calculated environmental chamber reactivity results 

for the dearomatized alkanes mixed, predominately C10-C12 (ASTM-1C), synthetic 

isoparaffinic alkane mixture, predominately C10-C12 (ASTM-3C1), Reduced 

Aromatics Mineral Spirits (ASTM-1B), and Regular mineral spirits (ASTM-1A) 

solvents studied by Carter and Malkina (2005). .................................................................. 371

Figure C-107. Plots of experimental and calculated environmental chamber reactivity results 

for the aromatic-100 solvent studied by Carter and Malkina (2005). .................................. 372

Figure C-108. Plots of experimental and calculated environmental chamber reactivity results 

for ethanolamine and isopropyl amine. In order to obtain the fits shown, the initial 

amine concentrations had to be adjusted to optimize the model fits to the reactivity 

data....................................................................................................................................... 372

Figure C-109. Plots of experimental and calculated environmental chamber reactivity results 

for t-butyl amine and 2-amino-2-methyl-1-propanol. In order to obtain the fits 

shown, the initial amine concentrations had to be adjusted to optimize the model fits 

to the reactivity data............................................................................................................. 373

Figure C-110. Plots of selected experimental and calculated concentration-time plots for the 

methyl iodide - NOx, methyl iodide - CO - NOx, and methyl iodide - O3 experiments. ...... 374

Figure C-111. Plots of experimental and calculated environmental chamber reactivity results 

for the methyl iodide experiments of Carter (2007)............................................................. 375
1

EXECUTIVE SUMMARY

Background

Airshed models are essential for the development of effective control strategies for reducing

photochemical air pollution because they provide the only available scientific basis for making 

quantitative estimates of changes in air quality resulting from changes in emissions. The chemical 

mechanism is an important component of the model that represents the processes by which emitted 

volatile organic compound (VOC) pollutants and oxides of nitrogen (NOx) react to form secondary 

pollutants such as ozone (O3) and other oxidants. If the mechanism is incorrect or incomplete in 

significant respects, then the model's predictions of secondary pollutant formation may also be incorrect, 

and its use might result in implementation of inappropriate or even counter-productive air pollution 

control strategies.

One airshed model application where the accuracy of the chemical mechanism is important is the 

calculation of reactivity scales that measure relative impacts of different types of VOCs on ozone 

formation. VOCs differ significantly in their impacts on O3 formation, and regulations that take this into 

account are potentially much more cost-effective than those that regulate all VOCs equally. In view of 

this, several VOC regulations implemented (or being considered) in California take reactivity into 

account. The current California regulations use the Maximum Incremental Reactivity (MIR) scale 

calculated using the SAPRC-99 chemical mechanism. 

The SAPRC-99 mechanism includes representations of atmospheric reactions of almost 780 types 

of VOCs for reactivity assessment, and is widely used in other airshed modeling applications for research 

and regulatory applications. Although this represented the state of the art at the time it was developed, 

since then there has been continued progress in basic atmospheric chemistry, and new information has 

become available concerning the reactions and O3 impacts of many individual VOCs. In addition, the 

California Air Resources Board (CARB) is obligated to update the reactivity scales used in its regulations 

approximately every three years so they reflect the current state of the science. Since the mechanism was 

developed in 1999, updates to the mechanism and the reactivity scale are now due.

Another reason for updating the SAPRC mechanism is to make it more suitable for prediction of 

secondary particulate matter (PM), which is another air quality issue of concern. SAPRC-99, like most 

other mechanisms used in current airshed models, incorporates simplifications and approximations that 

may be appropriate for O3 modeling, but that restricts its capability to represent how secondary organic 

aerosol (SOA) formation is affected by chemical conditions. This needs to be addressed.

In view of this, the CARB funded us to provide an update to the SAPRC-99 mechanism used for 

modeling and VOC reactivity assessment, and to provide some needed improvements and enhancements. 

This report documents this mechanism, its evaluation against available environmental chamber data, and 

the updated reactivity scales that were developed.

Accomplishments

The major accomplishment of this project is the development of the SAPRC-07 chemical 

mechanism and its associated reactivity scales, which are documented in this report. Specific 

accomplishments are summarized as follows.

Base mechanism updated. All the reactions and rate constants in the mechanism have been 

reviewed based on results of current evaluations, and updated as needed. Most of the rate constant 

changes were relatively small, but a few errors were found and corrected and some potentially significant 

changes occurred. These have been assessed in the evaluations against chamber data.
2

Aromatics mechanisms reformulated. The mechanisms for the aromatic ring fragmentation 

reactions were reformulated to be more consistent with estimated explicit mechanisms, and to give 

predictions that are somewhat more consistent with available data. However, although an improvement 

over that used in SAPRC-99, the updated mechanism is still simplified in many respects, and is still not 

completely consistent with all of the available data 

Chlorine chemistry added. A representation of chlorine chemistry has been added to the 

mechanism as an optional capability. In addition to improving the ability of airshed models to simulate air 

quality in regions impacted by chlorine emissions, the representation of chlorine chemistry has resulted in 

reduced uncertainties in reactivity estimates for chlorinated VOCs.

Capability for adaptation to SOA predictions improved. The method that the mechanism used to 

represent the reactions of peroxy radicals was reformulated so that effects of changes in NOx conditions 

on organic product formation can be more accurately represented. Because development of SOA 

mechanisms was beyond the scope of this project, the current mechanism does not fully take advantage of 

this capability, but it provides a framework upon which improved SOA mechanisms can be developed.

Mechanisms for many types of VOCs added or improved. The number of types of VOCs for 

which reactivity estimates have been made has been increased by over 20%, and the methods used to 

estimate mechanisms for a number of compounds were improved. This has involved enhancements of the 

capabilities of the mechanism estimation and generation system that is used to derive many of the 

mechanisms, and deriving estimated mechanisms for new classes of VOCs. A few errors found in the 

SAPRC-99 mechanism for some VOCs were corrected.

Updated mechanism evaluated against chamber experiments. The updated mechanism was 

comprehensively evaluated by comparing predictions with results of all environmental chamber 

experiments used for SAPRC-99 evaluation, plus the results of more recent UCR experiments, and 

experiments in other chambers. The results are summarized below.

Reactivity scales updated. The updated mechanism used to calculate MIR and other reactivity 

scales for all the ~1100 types of VOCs that are currently represented. Uncertainty classifications were 

also updated as part of this work. It is recommended that these be used to supercede the reactivity values 

distributed previously.

The mechanism developed in this project was implemented for the box model calculations used 

for reactivity scale calculations, and the data files used in this implementation can serve as the basis for 

implementing in more comprehensive airshed models such as CMAQ or CAMx. The data files are being 

made available at the project web site at http://www.cert.ucr.edu/~carter/SAPRC.

Results

Evaluation Results. In general, the performance of the updated mechanism in simulating the 

available environmental chamber data for individual compounds was comparable to SAPRC-99, though 

there were some differences. Some uncertain parameters for some compounds that were adjusted to fit the 

data for SAPRC-99 had to be re-adjusted for this mechanism. The updated aromatic mechanism simulated 

most of the experiments about as well as SAPRC-99, but some discrepancies observed with the previous 

version were reduced. Model performance was improved in simulating data for some compounds whose 

mechanisms were not changed, but biases were slightly increased with others. This is attributed to 

changes in the base mechanism, but the specific causes have not been determined. 

One area of potential concern is that the mechanism update caused a slight increase in overall 

biases in model simulations of experiments with mixtures of VOCs. These changes are small compared to 

the 30% variability of the fits overall – which is less than the average biases – but because of the large 

number of such experiments (>1500 total) it may be statistically significant. The mechanism update also 

did not solve the problem, noted previously for other mechanisms, of underpredicting O3 formation and 
3

NO oxidation in ambient surrogate - NOx experiments carried out at relatively low NOx levels in the new

UCR EPA chamber. These biases cannot be attributed to problems with individual VOCs, whose 

experiments are generally reasonably well simulated.

Preliminary assessment of impacts of updates on predictions of ambient ozone. Results of box 

model simulations of 1-day urban scenarios used for the reactivity scales indicate that the mechanism 

update caused changes in maximum ozone concentrations ranging from a ~10% decrease to a ~5% 

increase, with the predicted O3 decreasing by about 5% on average. The largest increase appears at the 

lower ROG/NOx ratios, but other factors appear to be equally important. However, the scenarios used in 

the reactivity assessment calculations are highly simplified representations of ambient conditions, and 

comprehensive models are needed to fully assess the impacts of this update on ambient ozone and control 

strategy predictions.

Reactivity Scale Update. For most VOCs, the reactivity scale update did significantly affect the 

reactivity values, with the average change in relative MIR values for the VOCs on the previous scales, 

being on the order of 10%. However, the MIR value changed by more than 5% for 56% of the VOCs 

given in the previous tabulation. The MIR change was less than 30% for approximately 93% of these 

VOCs, but 35 VOCs had changes greater than 35% and 5 VOCs had changes greater than a factor of 2.

The latter consisted of halogenated compounds and one compound where a rate constant error was 

corrected.

Recommendations

Although the accomplishments of this project were significant, there were some objectives of this 

project that could not be met within the available time and resource, and there are other areas where 

additional work is recommended. These are summarized below.

Aromatics Mechanisms. Although the aromatics mechanisms developed in this work represent an 

improvement, problems remain and additional work is needed. Work was begun during this project in 

developing a more explicit aromatics mechanism, and new environmental chamber data useful for this 

effort was obtained. Work in this area needs to continue. 

Chlorine and Halogen Mechanisms. Uncertainties remain in the mechanisms of halogenated 

compounds. Estimation methods need to be developed for reactions of halogen-containing radicals, and 

reactivities of halogenated oxidation products need to be assessed. Reactivity data are available for only a 

limited number of such compounds, and the available data indicates problems that need to be addressed. 

Mechanisms for bromine chemistry need to be developed.

Mechanism Generation System. An important component of the current mechanism is the 

mechanism generation and estimation system that is used to derive the mechanisms for most of the nonaromatic VOCs that are represented. However, because of time constraints we were unable to update most 

of the estimation methods incorporated in the system, except for the initial VOC rate constants and those 

related to chlorine chemistry. This needs to be done. The capability of the system needs to be enhanced to 

more reliably estimate mechanisms for additional classes of VOCs and intermediates, such as halogenated 

radicals, aromatics, and aromatic products. This will make it valuable for future mechanism 

improvements and reactivity scale updates. Finally, the system needs to be undergo peer review and be 

documented in the peer-reviewed literature.

Adaptation to SOA Predictions. Although the capability of the mechanism for improved SOA 

predictions has been enhanced, the potential of this capability has not been exploited. Recommendations 

in this regard include adding new species to the mechanism to represent low volatility products, 

implementing methods in the mechanism generation system to estimate volatility and incorporate them in 

the mechanisms so derived, and evaluating the predictions against SOA formation measured in chamber 

experiments. 
4

Mechanism Performance Issues. The reason that the mechanism has biases in simulations of 

mixture experiments, while simulating single compound experiments reasonably well, needs to be 

investigated. This is necessary to assess the implications on ambient simulations of the biases in the 

simulations of the mixture experiments that were found, and for developing methods to reduce these 

biases. The reason for the relatively poor performance of the mechanisms in simulating the University of 

North Carolina outdoor chamber database also needs to be investigated. Although existing tools involved 

in sensitivity, uncertainty, and process analysis may be useful, new analysis methods probably need to be 

developed. This is an area where original research is needed.

Mechanism Evaluation Database. Although the database of chamber experiments useful for 

mechanism evaluation is very extensive and comprehensive in some respects, there are gaps and problems 

that need to be addressed. There are a number of classes of compounds where reactivity chamber data are 

needed to reduce mechanism uncertainties. Incremental reactivity experiments need to be developed that 

are more sensitive to reactions of organic oxidation products, which affect predicted reactivities in 

ambient scenarios much more than in chamber experiments. The current chamber dataset is not adequate 

for evaluating effects of temperature on mechanism performance. Experiments are needed for testing 

mechanisms for predictions of SOA formation, particularly under lower pollutant conditions more 

representative of ambient conditions than are most PM chamber data.

Mechanism Condensation. One of the objectives of this project that was not accomplished was to 

develop a condensed version of the mechanism to serve as an alternative to CB4/CB05 for modeling 

applications where computer speed is more important than chemical detail. This still needs to be done.

Reactivity Scenarios. The scenarios used for deriving the reactivity scales developed in this work 

are poorly documented, oversimplified, and do not represent current ambient conditions. Evaluations 

carried out by the Reactivity Research Working Group (RRWG) indicate that this methodology could be 

improved in a number of respects, particularly the scenarios and modeling methods. This update is way 

overdue, and may result in changes in relative reactivity values that are greater than those resulting from 

updates to the mechanism.

Next Mechanism Update. The CARB is still committed to updating its regulatory reactivity scale 

on a periodic basis. This will obviously need to include updated reactivity scenarios, as indicated above. 

Another problem is that the developer of the SAPRC mechanisms and the MIR scale is now semi-retired, 

and may be completely retired by the time the next update is needed, and it is unclear who will be 

carrying out this work in the future. Funding agencies need to show an interest in providing support for 

this type of mechanism development on a sufficiently consistent basis that it will attract younger 

researchers into this field. As it is now, support for mechanism development is relatively limited, and not 

of the type needed for the long-term commitment that this type or research requires.
5

INTRODUCTION

Airshed models are essential for the development of effective control strategies for reducing

photochemical air pollution because they provide the only available scientific basis for making 

quantitative estimates of changes in air quality resulting from changes in emissions. The chemical 

mechanism is the portion of the model that represents the processes by which emitted primary pollutants, 

such as volatile organic compounds (VOCs) and oxides of nitrogen (NOx), interact in the gas phase to 

form secondary pollutants such as ozone (O3) and other oxidants. This is an important component of 

airshed models because if the mechanism is incorrect or incomplete in significant respects, then the 

model's predictions of secondary pollutant formation may also be incorrect, and its use might result in 

implementation of inappropriate or even counter-productive air pollution control strategies.

One airshed model application where the accuracy of the chemical mechanism is particularly 

important is the assessment or implementation of control strategies to encourage use of VOCs that have 

lower impacts on ozone or other secondary pollutant formation than VOCs that are currently emitted. 

Such strategies require a means to quantify the impacts, or "reactivities" of the VOCs with respect to O3

or other measures of air quality. There are several examples of control strategies where accurate O3

reactivity estimates are important. In the California Air Resources Board (CARB)’s "Low Emissions 

Vehicle/Clean Fuels" regulations, "reactivity adjustment factors" are used to place exhaust emissions 

standards for alternatively-fueled vehicles on an equal ozone impact basis as those for vehicles using

conventional gasoline (CARB, 1993). More recently, the CARB implemented reactivity-based regulations 

for aerosol coatings (CARB, 2000), and is considering expanding such regulations to other types of 

stationary sources (e.g., CARB, 2006, 2007). In addition, the EPA has used O3 impacts of VOCs 

calculated for various environments among the factors they consider when evaluating proposals to exempt 

various compounds from controls as ozone precursors (Dimitriades, 1999).

The MIR scale initially adopted in the CARB vehicle regulation was calculated using the 

SAPRC-90 chemical mechanism (Carter, 1990), but it has since been recalculated using an updated 

version of this mechanism, designated SAPRC-99 (Carter, 2000, 2003a). This mechanism has assigned or 

estimated mechanisms for over 500 types of VOCs. Although other state-of-the-art mechanisms are 

available for airshed model applications (e.g., Stockwell et al, 1997; Yarwood et al, 2005, Jenkin et al, 

2003; Saunders et al, 2003), the SAPRC mechanisms were used for this purpose because they are the only 

mechanisms that represent a large number of VOCs that was comprehensively evaluated against 

environmental chamber data. However, although the SAPRC-99 mechanism represented the state of the 

art at the time it was developed, since then there has been continued progress in basic atmospheric 

chemistry, and new information has become available concerning the reactions and O3 impacts of many 

individual VOCs. In addition, the CARB is obligated to update the reactivity scales used in its regulations 

approximately every three years so they reflect the current state of the science. Since the last update was 

made in 2003 (Carter, 2003a), updates to the scale are now due.

In addition to calculation of reactivity scales for regulatory applications, a condensed version of 

the SAPRC-99 mechanism (Carter, 2000b) is widely used in comprehensive airshed models for prediction 

of effects of emissions on secondary pollutant formation in regional and urban atmospheres. Such 

regional models are required for many research and regulatory applications, so they should represent the 

current state of the science. In the United States, the two alternative mechanisms most generally used in 

comprehensive airshed models are the Carbon Bond 4 (CB4) (Gery et al, 1988) and the SAPRC-99 

mechanism, and the two mechanisms have been found to give quite different predictions in some cases. 

The use of CB4 is preferred for many model applications because of it compact nature and because it is 

more computationally efficient, but SAPRC-99 is preferred in applications where chemical accuracy is a 

priority because it is more chemically detailed and more comprehensively evaluated against available 

environmental chamber data. CB4 has recently been updated to "Carbon Bond 05" (CB05) (Yarwood et 
6

al, 2005; Sarwar et al, 2008), and this is now being implemented in such models. Therefore, SAPRC-99 

needs to be updated so it can continue to be a viable alternative to the Carbon Bond mechanisms for 

applications where chemical accuracy is a priority.

Another reason for updating the SAPRC mechanism is to make it more suitable for prediction of 

secondary particulate matter (PM). Fine particulate matter pollution an important issue because of the 

major health impacts it is believed to cause, and secondary PM is a major contribution to this problem. 

The formation of secondary PM is even more complex and incompletely understood than the formation of 

ozone. Models for prediction of secondary PM have appended aerosol models to gas-phase mechanisms 

such as SAPRC-99 and CB4, but the treatment is necessarily parameterized and approximate because of 

the condensation approaches incorporated in these mechanisms. These approaches may be appropriate for 

ozone modeling, but are not necessarily appropriate for prediction of secondary organic aerosol. For 

example, such mechanism use lumped species to represent oxidation products based on their gas-phase 

reactivity, but without considerations of volatility, which is the major factor in secondary organic aerosol 

(SOA) formation. In addition, SAPRC-99, like CB4 and CB05, uses a condensed method to represent the 

many peroxy + peroxy radical reactions that does not readily permit models to represent how organic 

product distributions may change under very low NOx conditions where these reactions are important. 

Recent data (e.g., Song et al, 2005) indicate that, at least for aromatics, secondary PM formation may be 

much more dependent on NOx conditions than represented in current models. The condensation methods 

used in current mechanisms need to be modified to be more suitably adapted for models for PM 

prediction

Based on these considerations, the California Air Resources Board funded us to develop and 

document an updated version of the SAPRC mechanism, and use it to derive updated MIR and other 

VOC ozone reactivity scales. The specific objectives of the project were as follows:

 Update rate constants and reactions to current state of science.

 Improve mechanisms for aromatics to incorporate new data and improve performance in 

simulating available chamber data.

 Conduct environmental chamber experiments as appropriate to support this effort.

 Add chlorine chemistry, to support modeling areas impacted by chlorine emissions and also 

calculating reactivities of chlorinated organics.

 Update and enhance the mechanism generation system used to derive the mechanisms for most of 

the VOCs (Carter, 2000a). This includes updating the estimation methods and assignments as 

needed, and also enhancing the capabilities of the system, e.g., to support generating explicit 

mechanisms for aromatics and chlorine atom reactions;

 Improve capability of the mechanism to be adapted to secondary PM models

 Increase the number of VOC mechanisms to include more compounds present in emissions 

inventories or otherwise of interest to the CARB.

 Develop new condensed mechanisms from the detailed version (including a highly condensed 

version as an alternative to CB4).

 Make the mechanism available for implementation in airshed models

 Calculate updated reactivity scales and update associated uncertainty classifications.

The major accomplishments of this project are the development of a completely updated version 

of SAPRC-99, which is designated SAPRC-071, and the update of the associated MIR and other reactivity 

 

1

SAPRC stands for "Statewide Air Pollution Research Center", which is the unit at the University of 

California at Riverside where the SAPRC mechanisms were initially developed. This unit has since been 
7

scales, and their uncertainty classifications. The bulk of this report consists of the documentation of this 

mechanism and its evaluation, and the reactivity scales. The final section of this report includes a 

summary of the accomplishments of this project, the objectives that were not fully addressed, 

recommendations for future research.

 

renamed to "Air Pollution Research Center" (APRC), so strictly speaking this acronym is no longer 

meaningful. However, this designation for these mechanisms is retained for continuity.
8

MECHANISM DOCUMENTATION

The major components of the SAPRC mechanisms are the base mechanism used to represent the 

reactions of the inorganic reactants and the common organic oxidation products and radicals, the 

representation of the reactions of the individual VOCs, the lumped mechanism used for complex mixtures 

in airshed models, and the emissions assignments necessary for implementing the mechanism in airshed 

models. The general structure of this mechanism is essentially the same as that for SAPRC-99 mechanism 

documented by Carter (2000a), except that in this case chlorine chemistry is added and can be 

incorporated in the base and lumped mechanisms as an option, and is incorporated in representations and 

reactivity calculations for halogenated VOCs as needed. Each of these components, and their updates 

relative to SAPRC-99 are discussed in this section of this report.

Reference is made to the comprehensive documentation of the SAPRC-99 mechanism (Carter, 

2000a) for documentation of the features of the mechanism that were retained in this version, so that 

document must be considered an integral part of the documentation of this mechanism. Appendices to the 

report include the tabulations or data plots that are too large to include in the main body of the text, and 

additional information, such as complete listings of the mechanisms of the over 700 types of VOCs that 

are explicitly represented, is available in electronic form at the SAPRC mechanism website at 

http://www.cert.ucr.edu/~carter/SAPRC.

Base Mechanism

The base mechanism is the portion of the mechanism that represents the reactions of the inorganic 

species, the common organic products, and the intermediate radicals leading to these products, including 

those formed from the initial reactions of the represented VOCs not in the base mechanism. Most of the 

VOCs that can be separately represented are not in the base mechanism, but can be added to the 

mechanism, either as explicit reactions for individual VOCs or as lumped model species whose 

parameters are derived from the mixture of detailed model species they represent, as needed in the model 

application. However, a few VOCs are represented explicitly and incorporated in the base mechanism, 

either because they are also common organic oxidation products that are represented explicitly, or are 

sufficiently important in emissions inventories and have sufficiently different mechanisms than most 

other VOCs that representation with lumped model species is inappropriate. These include formaldehyde, 

acetaldehyde, acetone, ethylene, isoprene, and (new to this version) benzene and acetylene. This portion 

of the mechanism is discussed in this section.

Listing of Standard Base Mechanism and Summary of Changes

The "Standard Base Mechanism" is the portion of the base mechanism excluding the optional 

additional reactions used to represent chlorine chemistry, and is the portion that is directly comparable to 

the SAPRC-99 base mechanism. Table A-1 in Appendix A gives the list of model species used in the 

standard base SAPRC-07 mechanism. These include the inorganic reactants, common reactive organic 

product species, chemical operators used to represent peroxy radical reactions (discussed below), and 

explicitly represented primary organics. Except as discussed below, the species used are the same as in 

the base SAPRC-99, though some model species have been renamed to be more compatible with some 

airshed model software systems. The changes, and additions, are as follows:

 The set of lumped peroxy radical species and chemical operators was changed because as 

discussed in the "Project Summary" section, above, a different method was used to represent 

peroxy radical reactions. SAPRC-99 used three active chemical operators (RO2-R., RO2-N., and 

R2O2.) to represent the effects of peroxy radical reactions on NOx and organic nitrates. The 

updated mechanism uses two active chemical operators (RO2C and RO2XC) to represent the 
9

effects of peroxy radical reactions on NOx and 34 steady-state operators to represent the effects 

on formation of organic products (not counting the 3 used in the added chlorine mechanism).

Two additional model species were added to represent the reactions of the higher hydroperoxides 

that were previously lumped with one generic hydroperoxide species in SAPRC-99. These higher 

hydroperoxides are expected to have different reactivities and SOA formation potentials than 

propyl hydroperoxide, which was used as the basis for the single generic hydroperoxide in 

SAPRC-99.

 Although three active model species are still used to represent the reactions of the unsaturated 

aromatic ring fragmentation products, the types of compounds they represent have been changed. 

This is discussed in conjunction with the discussion of the revised aromatic mechanisms, below.

 The reactions of formic acid, acetic acid, and the lumped higher organic acids were added to the 

mechanism. These species were in SAPRC-99 as inert tracers, but their reactions with OH 

radicals were added to this mechanism because they may be non-negligible loss processes in 

some regional modeling applications.

 Acetylene and benzene are now represented explicitly in this mechanism. This is because both 

compounds are relatively important in emissions inventories, their reactivities are quite different 

than the other compounds with which they previously were lumped (monoalkylbenzenes and low 

reactivity alkanes, respectively), and are not well represented by other species used in the lumped 

mechanism. In addition, explicit simulations of benzene are of interest for toxics modeling, and 

acetylene can provide a useful tracer for vehicle emissions.

Although the objective of this update was to provide a mechanism with similar or, if appropriate, 

greater level of detail as SAPRC-99, a few SAPRC-99 model species were judged to be unnecessary and 

were removed from this version. These are as follows.

 Phenol was removed from the mechanism because it is important only in the oxidation of 

benzene, and representing it by the lumped cresol species (CRES) did not significantly affect 

results of simulations of benzene, whose mechanism is very uncertain in any case.

 The SAPRC-99 model species BZNO2-O, used in the mechanism for the reaction of NO3 with 

lumped nitrophenols, was removed. It was found that representing it with the phenoxy model 

species used in the cresol mechanism gave model simulations that were essentially the same, 

especially considering the large uncertainty in the nitrophenol and cresol mechanisms.

 The SAPRC-99 model species CCO-OOH and RCO-OOH, used to represent various peroxy 

acids formed in the reactions of acyl peroxy radicals with HO2, were removed. These are 

represented by the reactions of the corresponding acid model species. It was judged that separate 

representation of these species was not necessary, though this could be changed in future versions 

of the mechanism if desired.

The reactions and rate parameters used in the base mechanism are given in Table A-2 in 

Appendix A, and Table A-3 gives the absorption cross sections and quantum yields used for the 

photolysis reactions listed in this table. Footnotes to Table A-2 indicate the source of the rate constants 

and mechanisms used. As indicated there, most of the updated rate constants are based on results of the 

IUPAC (2006) and NASA (2006) evaluations, though a number of other sources were also used as the 

basis for the updates. The major changes to the inorganic and common organic radical and product 

mechanisms are discussed further below. The changes to the mechanisms for the explicitly represented 

species are discussed later in conjunction with the mechanisms for the other individual VOCs.

Table 1 shows the changes in rate constants or atmospheric photolysis rates for this version of the 

base mechanism compared to SAPRC-99, for the cases where the rate constants or photolysis rates were 

changed by more than 5%. Reactions used to represent unsaturated aromatic ring fragmentation products, 

or reactions of chemical operators used to represent peroxy radical reactions are not shown because the 
10

representations are not comparable on a reaction-by-reaction basis; these are discussed below or later in 

this report. Specific changes of potential interest are as follows.

 The most important single change to the base mechanism may be the ~19% increase in the rate 

constant for the OH + NO2 reaction, based on the results of the recent NASA (2006) evaluation. 

This affected the mechanism evaluation against the chamber experiments because it required rederiving some chamber effects parameters and also some uncertain mechanistic parameters 

derived to fit chamber data. It is also expected to result in somewhat lower O3 predictions in 

ambient simulations, though this may be offset somewhat by the changes in the parameters 

adjusted to fit chamber data.

 The ~7% increase in the NO2 photolysis rate under atmospheric conditions has no effect on NO2

photolysis rates used in chamber simulations because all photolysis rates are normalized to 

measured NO2 photolysis rates. However, rates of other photolysis reactions in chamber 

simulations will decrease accordingly.

 There was a relatively large increase in the calculated atmospheric photolysis rates for the -

dicarbonyl aromatic ring fragmentation products. However, this will not result in increases in 

calculated reactivities of aromatics because of changes that were made to the representation of the 

other reactive aromatic fragmentation products, discussed later in this report.

 The ~30% increase in the calculated photolysis rates for methacrolein and the model species used 

to represent C5 aldehyde products formed from isoprene did not seem to have a significant effect 

on simulations of isoprene chamber experiments or calculations of the atmospheric reactivity of 

this important biogenic compound. Despite the relatively large decrease in the peroxy + HO2 rate 

constant, this reaction is still calculated to be the major loss process for peroxy radicals 

competing with reaction with NO under low NOx conditions.

 The photolysis of PAN was added to the mechanism at the request of Deborah Luecken of the 

EPA. Although not important in urban simulations, this reaction may be important under low 

temperature conditions such as occur at higher altitudes.

 New information available concerning the reactions of nitrophenols indicates that the major 

atmospheric loss processes are photolysis and reactions with OH (see footnotes for these 

reactions on Table A-2). The speculative reaction of nitrophenols with NO3 was deleted, though it 

may still occur to some extent.

 As discussed below, the mechanism for PROD2 is based on mechanism for various C5-C9

ketones. The updated mechanism gives better simulations of incremental reactivity environmental 

chamber experiments for higher ketones if lower photolysis rates for higher ketones are assumed 

(see discussion of mechanisms of individual VOCs and the evaluation against chamber 

experiments later in this report). The overall quantum yield for photolyses of C7+ ketones are set 

to a sufficiently low value that photolysis is unimportant. This is reflected in the average overall 

quantum yield used for PROD2.

 As indicated above, several model species were removed and the base mechanism now explicitly 

represents the reactions of some additional compounds. These changes should have relatively 

small effects on most simulations except that atmospheric simulations will now simulate these 

species explicitly, rather than ignoring their reactions (as with the acids) or lumping them with 

other compounds. Note that this change does not, by itself, affect reactivity calculations for these 

compounds because the compound of interest (or the compound used to represent them if the 

"lumped molecule" approach is used) is always represented explicitly in reactivity calculations.
11

Table 1. Reactions where the rate constants or photolysis rates changed by more than 5% or that 

were added or removed in the standard base mechanism relative to SAPRC-99. 

Rate constant or photolysis rate [a] Reaction [b] Notes 

SAPRC-07 SAPRC-99 Change [c]

7.23e-1 6.69e-1 8% NO2 + HV = NO + O3P 1

1.64e-12 2.45e-12 -33% O3P + NO = NO2

1.03e-11 9.70e-12 6% O3P + NO2 = NO + O2

3.24e-12 1.79e-12 81% O3P + NO2 = NO3 2

2.02e-14 1.87e-14 8% O3 + NO = NO2 + O2

1.24e-12 1.53e-12 -19% NO2 + NO3 = N2O5

5.69e-2 6.74e-2 -16% N2O5 = NO2 + NO3

1.80e-39 N2O5 + H2O + H2O = #2 HNO3 + H2O 3

1.91e+0 1.59e+0 20% NO3 + HV = NO + O2

1.99e-10 2.20e-10 -10% O1D + H2O = #2 OH

3.28e-11 2.87e-11 14% O1D + M = O3P + M

1.14e-1 1.27e-1 -10% HONO + HV = OH + NO

- 1.60e-2 HONO + HV = HO2 + NO2

5.95e-12 6.42e-12 -7% OH + HONO = H2O + NO2

1.05e-11 8.81e-12 19% OH + NO2 = HNO3 1

2.28e-13 2.08e-13 10% OH + CO = HO2 + CO2

7.41e-14 6.78e-14 9% OH + O3 = HO2 + O2

8.85e-12 8.36e-12 6% HO2 + NO = OH + NO2

1.12e-12 1.36e-12 -18% HO2 + NO2 = HNO4

1.07e-1 9.61e-2 11% HNO4 = HO2 + NO2

5.42e-4 4.69e-4 16% HNO4 + HV = Products

4.61e-12 4.98e-12 -7% HNO4 + OH = H2O + NO2 + O2

1.69e-15 1.89e-15 -11% HO2 + O3 = OH + #2 O2

1.80e-12 1.70e-12 6% HO2H + OH = HO2 + H2O

4.65e-12 5.12e-12 -9% MEO2 + HO2 = COOH + O2

4.50e-13 MEO2 + HO2 = HCHO + O2 + H2O

2.16e-13 2.61e-13 -17% MEO2 + MEO2 = MEOH + HCHO + O2

1.31e-13 1.08e-13 21% MEO2 + MEO2 = #2 {HCHO + HO2}

7.63e-12 1.45e-11 -47% Peroxy + HO2 = Products 4

9.37e-12 1.04e-11 -10% MECO3 + NO2 = PAN

6.27e-4 7.04e-4 -11% PAN = MECO3 + NO2

6.12e-5 PAN + HV = Products 1

1.97e-11 2.12e-11 -7% MECO3 + NO = MEO2 + CO2 + NO2

2.30e-12 4.00e-12 -43% MECO3 + NO3 = Products 2,5

1.06e-11 9.53e-12 11% MECO3 + MEO2 = Products 5

1.56e-11 7.50e-12 108% MECO3 + Peroxy = Products 2,4,5

5.48e-4 5.90e-4 -7% PAN2 = RCO3 + NO2

2.08e-11 2.78e-11 -25% RCO3 + NO = Products

7.63e-12 1.45e-11 -47% BZO + HO2 = CRES

3.80e-11 BZNO2-O. + NO2 = inert products 6

1.49e-11 BZNO2-O. + HO2 = NPHE 6

1.00e-3 BZNO2-O. = NPHE 6

2.76e-3 2.32e-3 19% HCHO + HV = #2 HO2 + CO

8.47e-12 9.19e-12 -8% HCHO + OH = HO2 + CO + H2O
Table 1 (continued)

12

Rate constant or photolysis rate [a] Reaction [b] Notes 

SAPRC-07 SAPRC-99 Change [c]

1.49e-11 1.57e-11 -6% CCHO + OH = MECO3 + H2O

6.74e-15 3.82e-15 76% RCHO + NO3 = HNO3 + RCO3

3.24e-5 4.16e-5 -22% ACET + HV = Products

1.69e-4 1.42e-4 19% MEK + HV = Products

6.78e-12 1.10e-11 -38% ROOH + OH = Products

3.18e-3 1.08e-3 193% GLY + HV = HCHO + CO

1.56e-2 1.10e-2 42% MGLY + HV = HO2 + CO + MECO3

2.67e-2 1.90e-2 41% BACL + HV = #2 MECO3

2.63e-11 PHEN + OH = products 6

3.78e-12 PHEN + NO3 = products 6

3.50e-12 - NPHE + OH = BZO + XN 1

3.78e-12 NPHE + NO3 = products 1

1.08e-3 NPHE + HV = HONO + #6 XC 1

1.08e-2 NPHE + HV = #6 XC + XN 1

1.20e-11 1.29e-11 -7% BALD + OH = BZCO3

2.84e-11 3.35e-11 -15% MACR + OH = Products

1.28e-18 1.19e-18 8% MACR + O3 = Products

3.54e-15 4.76e-15 -26% MACR + NO3 = Products

1.97e-4 1.36e-4 45% MACR + HV = Products

1.99e-11 1.87e-11 6% MVK + OH = Products

5.36e-18 4.74e-18 13% MVK + O3 = Products

7.50e-5 6.97e-5 8% MVK + HV = Products

1.97e-4 1.36e-4 45% IPRD + HV = Products

4.69e-6 1.90e-5 -75% PROD2 + HV = Products 1

7.20e-12 7.80e-12 -8% RNO3 + OH = Products

4.50e-13 HCOOH + OH = HO2 + CO2 7

7.26e-13 CCOOH + OH =products 7

1.20e-12 RCOOH + OH = products 7

1.64e-11 - R6OOH + OH = products 7

3.94e-4 - R6OOH + HV = products 7

1.08e-10 - RAOOH + OH = products 7

3.94e-4 RAOOH + HV = products 7

7.56e-13 ACETYLEN + OH = products 7

1.16e-20 ACETYLEN + O3 = products 7

1.22e-12 BENZENE + OH = products 7

[a] Rate constants are for T=300oK and are in molecule, cm3sec-1units. Photolysis rates are calculated 

for direct overhead sunlight based on the actinic fluxes used in the reactivity scale calculations 

(Carter, 1994a,b).

[b] Reactions used to represent unsaturated aromatic ring fragmentation products, and reactions of

chemical operators used to represent peroxy radical reactions, are not directly comparable in the two 

mechanisms. They are discussed separately later in this report.

[c] Notes concerning changes for reaction. See also text and footnotes to Table A-2

1 See text for a discussion of this change.

2 This is a relatively minor process under most conditions of interest, so the change should not have 

a significant effect on most model predictions.
Table 1 (continued)

13

3 This reaction is added to represent the expected humidity dependence of this process.

4 "Peroxy" refers to the various model species used to represent various types of peroxy radicals or 

peroxy radical operators.

5 The same rate constants are used for all the higher acyl peroxy radical model species.

6 This model species was deleted. See text.

7 The reactions of these compounds were added to the base mechanism. See text.

Note that the discussion given above of expected effects of these changes on model simulations is 

based on expectations that have not, in most cases, been verified by actual model sensitivity calculations. 

Such sensitivity calculations would be useful to assess the effects of various changes, and help focus on 

areas where basic research may be useful.

Representation of Peroxy Radical Operators

Because of the large number of peroxy radicals that are involved even in condensed atmospheric 

chemistry mechanisms, it is generally not practical to represent the many possible peroxy + peroxy

reactions explicitly, especially considering that under most conditions, especially conditions favorable for 

O3 formation, most of these reactions are relatively unimportant. Even highly explicit mechanisms such as 

the MCM (Jenkin et al, 2003; Saunders et al, 2003) use an approximate method to represent the many 

peroxy + peroxy cross reactions involving a chemical operator representing the total peroxy radical 

concentration. The RADM-2 and RACM mechanisms (Stockwell et al, 1990, 1997) have separate peroxy 

radical species for each VOC or VOC product model species whose reactions form peroxy radicals, but 

neglect peroxy + peroxy reactions except for those involving HO2 and methyl peroxy radicals. Because of 

the large number of reactions and model species involved even with the more approximate RADM-2 

representation, SAPRC-99 represents methyl peroxy radicals explicitly, but uses a limited number of 

"chemical operators" to represent effects of peroxy radical reactions on NOx and radicals, and represents 

the organic products formed when higher peroxy radicals react with other peroxy radicals by those 

formed when they react with NOx. The CB4/05 mechanisms use a similar, though somewhat more 

condensed approach.

Use of these condensed representations of peroxy radical reactions has been shown to have 

relatively little effects on predictions of O3 formation and overall gas-phase reactivity because they

involve no approximation when the major fate of peroxy radicals is reaction with NO, as is the case when 

O3 formation occurs, and because they give reasonably good representations of how NO to NO2

conversions, organic nitrate formation, and regeneration of radicals change when NOx levels are reduced 

to the point where the competing peroxy + peroxy become non-negligible. However the representations 

incorporated in SAPRC-99 and CB4/05 do not represent the changes in organic oxidation products that 

occur when these peroxy + peroxy reactions become non-negligible, since they use the set of products 

formed in the peroxy + NO reaction as the surrogate for the generally different products formed in the 

competing reactions. The inability of this representation to represent the formation of hydroperoxides 

formed in the peroxy + HO2 reaction is of particular concern, because these are predicted to be the major 

competing products formed under low NOx conditions (e.g., see Carter, 2004), and as discussed above are 

believed to be important precursors to secondary organic aerosol (SOA) formation.

Therefore, the peroxy radical representation used in SAPRC-99 is not satisfactory for use of the 

mechanism for prediction of SOA formation, and for this reason was changed as part of this update. The 

peroxy radical operator method implemented in SAPRC-99 is described in the SAPRC-99 documentation 

(Carter, 2000a). Briefly, it involves the operator RO2-R. to represent the reactions converting NO to NO2

forming HO2, RO2-N. to represent reactions with NO forming organic nitrates, and R2O2. to represent 

extra NO to NO2 conversions involved in multi-step peroxy radical reactions. Since it uses the set of 
14

products formed in the NO reaction to represent the products in the competing peroxy + peroxy reactions, 

it uses no additional model species for this purpose except for the inclusion of a generic "ROOH" species 

to represent reactions at the hydroperoxide group formed in the peroxy + HO2 reaction (with the set of 

products formed in the NO reaction also being formed in the HO2 reaction.)

The SAPRC-07 representation is similar in that operators are also used to represent the effects of 

peroxy radicals on NOx, with "RO2C" representing NO to NO2 conversions and "RO2XC" representing 

NO consumption that occurs in conjunction with nitrate formation, but uses separate chemical operator 

model species to represent the formation of radicals and oxidation products, and how they depend on 

which peroxy radical reactions are occurring. Three sets of chemical operators are used for this purpose: 

"xPROD" species are used to represent the formation of the alkoxy radical products resulting when the 

peroxy radical react with NO, NO3, and (in part) RO2; "yPROD" species are used to represent the 

formation of hydroperoxides formed when peroxy radicals react with HO2 or H-shift disproportion 

products formed when peroxy radicals react with acyl peroxy radicals or (in part) with RO2; and 

"zRNO3" species are used to represent the formation of organic nitrates when peroxy radicals react with 

NO or the alkoxy radical formed (in part) in RO2 + RO2 reactions. The products formed in the reactions of 

these operators are summarized on Table 2. Table A-2 and footnotes to Table A-2 indicate how they are 

implemented in the model.

Table 2. Products formed in the reactions of the chemical operators used to represent peroxy 

radical reactions in the SAPRC-07 mechanism.

Reaction RO2C RO2XC xPROD yROOH zRNO3

NO - NO + NO2 [a] - NO [a] PROD RNO3

NO3 - NO3 + NO2 [a] PROD PROD2 + HO2 [b]

HO2 ROOH

RO2· 

 RO·. PROD PROD2 + HO2 [b]

H-Shift MEK or PROD2 [c]

RC(O)O2· PROD PROD2 + HO2 [b]

[a] "-NO" or "-NO3" means that the reaction consumes these reactions. If this is not shown, it means that 

the reaction should not consume any reactant other than the peroxy radical operator. For example, the 

reaction of RO2C with HO2 would be simulated as "RO2C + HO2  HO2".

[b] This represents products formed from alkoxy radicals formed in the absence of NOx that are not 

represented by xPROD model species because they are not used for the portions of the reactions that 

form organic nitrates in the presence of NOx. The present version of the mechanism has only a single 

zRNO3 species, and uses PROD2 for this purpose. HO2 is used to represent the radicals formed.

[c] The model species used to represents the H-shift disproportion products depends on the size of 

molecules being represented by yROOH. For the operators forming the ROOH model species used 

for 4 or fewer carbons, MEK is used for these processes. For operators forming larger hydroperoxides 

(R6OOH or RAOOH), PROD2 is used.
15

Note that in this representation the total yield of RO2C or RO2C + RO2XC may be greater than 

unity in multi-step processes involving formation of secondary peroxy radicals that cause additional NO 

to NO2 conversions or nitrate formation. However, radical conservation requires that the sum of RO2XC 

and all xPROD operators where PROD is a radical be equal to 1 in VOC + radical (e.g., VOC + OH) 

reactions, and the sum of all yROOH species must be equal to the total yield of all peroxy radicals formed 

in the initial reaction.

The main approximation involved in this representation concerns the treatment of the cases of 

multi-step mechanisms where the peroxy radicals undergo reactions to form other peroxy radicals, which 

can react with NO or other peroxy radicals, etc. This would result in different (generally intermediate) 

branching ratios in the competitions of the peroxy radical reactions in terms of the overall products. In 

this representation it is assumed that the overall branching ratios, e.g., the extent to which hydroperoxides 

are formed from peroxy + HO2 reactions, are the same in multi-step as in single step mechanism. 

Removing this approximation would require a much more complex mechanism, with more operators or 

model species, than is appropriate given its level of importance. Note that this approximation is 

incorporated in all mechanisms that use the more approximate peroxy radical representations, such as 

SAPRC-99 or CB4/05. 

Although this representation can otherwise potentially give the same predictions as fully explicit 

mechanisms, it is not particularly intuitive from a chemical perspective. It involves using separate model

species for each type of product that is formed, and its "reactions" do not have a straightforward 

correspondence to explicit reactions. An alternative method, that is more straightforward to understand in 

terms of actual chemical processes (and gives the same predictions), is to use separate model species for 

each group of peroxy radicals formed from the reactions of each of the various VOCs, and represent the 

competing overall reactions of these lumped groups of peroxy radicals with NO, NO3, HO2, RCO3, and 

other peroxy radicals. Chemical operators would still be needed to represent NO to NO2 conversions in 

multi-step processes and to determine a total RO2 concentration for calculating peroxy + peroxy rates, but 

the result would be closer to the actual chemical processes that occur. This is the approach used in the 

RADM2/RACM mechanisms (Stockwell et al, 1990, 1997), with the problem of representing peroxy + 

peroxy reactions dealt with by ignoring all but reactions with methyl peroxy; which is not a bad 

approximation (Carter and Lurmann, 1990).

Although we considered use of the RADM2 approach for this mechanism, we had to abandon it 

because it was incompatible with the "lumped parameter" approach incorporated in the SAPRC 

mechanisms for flexible representation of the hundreds of individual VOCs or deriving parameters for 

lumped model species based on the specific compounds they represent. This representation involves 

having a numerical parameter represent each of the product or radical model species involved in their 

overall reactions, including NO to NO2 conversions and NO consumptions. This is not readily adaptable 

to the RADM2 peroxy radical representation because the overall products are not associated directly with 

the reacting VOCs but with their peroxy radicals, and the yield of peroxy radicals from VOCs can vary. 

On the other hand, it is readily adaptable to the peroxy radical representation incorporated in SAPRC-07, 

where each overall product is still directly related to each reacting VOC.

Base Chlorine Mechanism

The model species added to the base mechanism to represent the atmospheric reactions of 

chlorine species are listed on Table A-4 in Appendix A. These include 8 model species to represent active 

inorganic reactants and radicals, 2 to represent chlorine-containing oxidation products, 3 steady state 

chemical operators to represent formation of chlorine species in peroxy radical reactions, and 2 chlorinecontaining inert tracer species. Table A-5 gives the reactions and rate parameters used in the base chlorine 

mechanism, and Table A-6 gives the absorption cross sections and quantum yields for the photolysis 

reactions listed in this table. Footnotes to Table A-5 and indicate the source of the rate constants and 
16

mechanisms used. As indicated there, most of the rate constants are based on results of the IUPAC (2006) 

and NASA (2006) evaluations, though several other sources were also used in some cases.

Except for the updated rate constants and photolysis data, the base inorganic chlorine mechanism 

is very similar to that developed previously by Carter et al (1996a, 1997b). The major difference is the 

addition of separate model species to represent the reactions of chlorinated aldehydes and ketones that 

may be formed in the reactions of chlorinated VOCs. Carter and Malkina (2007) found that the 

reactivities of the 1,3-dichloropropenes are significantly underpredicted if the standard aldehyde model 

species are used to represent the reactions of the chloroacetaldehyde predicted to be formed, but 

satisfactory simulations are obtained if a separate model species is used, using the NASA (2006)-

recommended absorption cross sections and quantum yields for this compound. This is because this 

compound is calculated to photolyze ~15 times faster than acetaldehyde and ~4.5 times faster than the 

lumped higher aldehyde model species used in the standard base mechanism. This model species 

(CLCCHO) is also used to represent the reactions of other -chloroaldehydes, which are assumed to be 

similarly photoreactive. Because chloroacetone is calculated to photolyze ~7 times faster than MEK and 

even more for higher ketones, a chloroacetone (CLACET) model species is added to represent the 

reactions of -chloroketones. However, -chloro- aldehydes and ketones and other chlorinated aldehydes 

are still represented by the generic higher aldehyde or ketone species (RCHO, MEK, or PROD2) in the 

standard mechanism.

Chlorine atoms react rapidly with most reactive VOCs and any complete chlorine mechanism 

must include a representation of their reactions, at least for the VOCs present in the chamber experiments 

with chlorine-containing species, and for the explicit and lumped VOC species used in atmospheric 

models. The mechanisms for these reactions are discussed in conjunction with the mechanisms for 

individual VOCs and lumped mechanisms for airshed models, below.

Representation of Organic Products

The set of model species to represent the reactions of the organic oxidation products are given in 

Table A-1 in Appendix A. Some of these are compounds represented explicitly (e.g. formaldehyde) and 

some are lumped species whose mechanisms are derived based on that for a compound or group of 

compounds chosen as representative. In the latter case, the compound or compounds used to derive the 

mechanisms for the lumped species are given in Table A-1 and in applicable footnotes to Table A-2. 

Except for the additional species added to represent higher hydroperoxides and the removal of phenol and 

the organic peroxyacids (now lumped with cresols or organic acids, respectively), this mechanism uses 

essentially the same set of model species to represent the organic products, and the same set of 

compounds to derive their mechanisms in the case of lumped species, as does SAPRC-99. Therefore the 

discussion of these species, and the choice of representative compounds used to derive the mechanisms of 

the lumped species, given in the SAPRC-99 documentation (Carter, 2000a) are still applicable. However, 

the rate constants and in some cases the products used for the reactions of these species or representative 

compounds were updated, and the reactions of these species with chlorine atoms were added and 

incorporated in the base chlorine mechanism discussed above.

The optional added chlorine mechanism given in Table A-5 includes the reactions of Cl atoms 

with most of the model species used reactive organic products in the base mechanism. Although reactions 

of Cl with some organic product species have been omitted1, the processes represented should be 

sufficient for most ambient and chamber simulations, where the major sinks for the chlorine atoms or the 

product species are other reactions. As indicated above the added chlorine mechanism also includes 

model species for chlorinated aldehydes and ketones that may be formed from the reactions of chlorinated 

VOCs. The mechanism also includes the reactions of chlorine atoms with these compounds.

 

1 The reactions of Cl atoms with the following model species have been omitted: HCOOH, CCOOH, 

RCOOH, COOH, BACL, NPHE, AFG1, AFG2, and AFG3.
17

Mechanisms for Individual VOCs

An important distinguishing feature of the current SAPRC mechanisms is their ability to 

optionally include separate representations of the atmospheric reactions of many hundreds of different 

types of VOCs. Generally these are not all included in the airshed model at the same time, but selected 

individual compounds can be represented explicitly for the purpose of calculating reactivity scales or for 

toxics modeling, or mechanisms for groups of compounds can be used for deriving parameters for lumped 

model species used for representing complex mixtures such as ambient emissions. The current mechanism 

has separate explicit representations for 734 types of VOCs, making it the most comprehensive in terms 

of types of VOCs than any current gas-phase atmospheric mechanism. In addition, for deriving reactivity 

scales or representations of complex mixtures, 304 additional types of VOCs are represented using the 

"lumped molecule approach", where their impacts are estimated by assuming they are the same, on a per 

molecule basis, of an explicitly represented VOC. This yields a total of 1038 types of VOCs that are 

represented by a "detailed model species" in the mechanism.

A listing of all of the detailed model species in the SAPRC-07 in the mechanism, their molecular 

weights and general representation method (explicit or lumped molecule) is given in Table B-1 in 

Appendix B. That table also gives codes for availability of mechanism evaluation data, calculated ozone 

reactivity values, and reactivity uncertainty classifications. Table B-2 and Table B-4 through Table B-6

give the reactions and rate parameters for all the explicitly represented VOCs, Table B-3 gives the 

mechanisms for those VOCs where "adjusted product" mechanisms (discussed below) were used in the 

reactivity calculations, Table B-7 gives the mechanisms for the reactions of chlorine with the VOCs that 

were used in developing the fixed parameter lumped mechanism discussed in the following section. In

addition to giving the OH radical rate constants and references for all VOCs that are explicitly represented 

in the mechanism, Table B-4 gives codes indicating the general type of mechanism used for each, and 

gives the structures used for compounds whose mechanisms were derived using the mechanism 

generation system. Footnotes to Table B-2 and Table B-4 through Table B-7 document the sources of the 

rate constants used, and Table B-8 gives the absorption cross sections and quantum yields for those that 

are photoreactive and have different absorption cross sections and quantum yields than those used in the 

base mechanism. Table B-9 gives the lumped molecule assignments used for the types of VOCs that are 

represented using this approximation. The derivations of these mechanisms are discussed further in the 

remainder of this section.

Mechanism Generation and Estimation System

A major tool used in the derivation of the SAPRC-99 mechanisms for individual VOCs was the 

automated mechanism generation and estimation software system that is described in the SAPRC-99 

documentation (Carter, 2000a). Given the structure of the molecule, available information concerning 

applicable rate constants and branching ratios, and various estimation methods, this system can derive 

fully explicit mechanisms for the atmospheric reactions of many classes of VOCs in the presence of NOx, 

and then use these mechanisms to derive the appropriate representations of the VOCs in terms of the 

model species in the base mechanism. This was used to derive the SAPRC-99 mechanisms for the acyclic 

and monocyclic alkanes, acyclic and monocyclic monoalkenes, many classes of oxygenates including 

alcohols, ethers, glycols, esters, aldehydes, ketones, glycol ethers, carbonates, etc, and the organic nitrates. 

Although many of the estimated rate constants and rate constant ratios are highly uncertain, this procedure 

provided a consistent basis for deriving "best estimate" mechanisms for chemical systems which are too 

complex to be examined in detail in a reasonable amount of time. The system allows for assigning or 

adjusting rate constants or branching ratios in cases where data are available, or where adjustments are 

necessary for model simulations to fit chamber data. Therefore, it could be used for deriving fully detailed 

mechanisms for VOCs that fully incorporate whatever relevant data are available, relying on various 

estimation methods only when information is not otherwise available. The program also outputs 

documentation for the generated mechanism, indicating the source of the estimates or assumptions or 

explicit assignments that were used.
18

This SAPRC-99 mechanism generation system, with some enhancements and updates as described 

below, was also used for deriving mechanisms for many of the VOCs in the SAPRC-07 mechanism. Since 

this system is comprehensively documented by Carter (2000a) and most of the estimation methods were not 

updated as part of this project, in this section we will restrict our discussion to the changes, updates, and 

enhancements that were made as part of this project and utilized when deriving the updated mechanisms for 

the individual VOCs. These are described below

Enhanced Capabilities for VOCs and Reactions

During the period of this project, the capabilities of the mechanism generation system 

were enhanced to support generating mechanisms for VOCs and radicals that could not previously be 

processed. These are briefly summarized below. These enhancements, and the associated estimates and 

branching ratio assignments, will be described in more detail in a future report when the current system is 

more comprehensively documented.

 Reactions of VOCs with chlorine atoms can now be generated. This is discussed in the following 

subsection.

 The ability to represent compounds with more than one ring has been added. This required 

revising the way structures were identified. Because of this, mechanisms for terpenes can now be 

generated. This is also useful in generating estimated mechanisms for aromatics, discussed below.

 The ability to represent compounds with more than one double bond has been added. This also 

required revising the way structures were identified. However, estimation methods for reactions 

of compounds with conjugated or cumulated double bonds were not developed, and automatically 

generated rate constants and branching ratios for OH and NO3 reactions of such compounds are 

not necessarily chemically reasonable, and reactions of O3 with compounds with more than one 

double bond are still not supported. Explicit assignments have to be made for such reactions, as 

was the case with, for example, isoprene and 1,3-butadiene.

 The ability to estimate reactions of unsaturated radicals has been added. The system recognizes 

allylic resonance and the probability of reaction at various positions of alkyl radicals with allylic

resonance is estimated by assuming that the probability of reaction at a particular structure is 

proportional to exp(Hf/RT), where Hfis the estimated heat of formation of the structure, R is the 

gas constant, and T is the temperature. If the heat of formation cannot be estimated, equal 

probability for reaction at all positions (or the positions with the most conjugated double bonds if 

there are more than one double bond) is assumed. 

 Reactions involving H-atom abstractions are now considered when generating mechanisms for 

reactions of OH, NO3, and Cl with alkenes. These previously had to be assumed to be negligible 

because of lack of support for generating mechanisms for unsaturated radicals. These are still 

neglected if they are estimated to occur less than 1% of the time, as is generally the case in OH 

and NO3 reactions. However, abstraction reactions are generally not negligible in chlorine + 

alkene reactions, as discussed below. 

 The ability to generate mechanisms for amines (compounds with >N-, -NH-, or -NH2 groups) was 

added. The new amine mechanisms, and their evaluation against chamber data, are documented 

by Carter (2008a). The available kinetic data indicates that reaction with OH occurs by H-atom 

abstraction from the amino group and that the rate of H-atom abstraction from the carbon next to 

the amino group is significantly enhanced, and group-additivity estimates for rates of reaction at 

these positions were derived. The data of Aschmann and Atkinson (1998) on N-methyl 

pyrrolidinone (NMP) indicate that reaction of amines with NO3 radicals may also occur to a nonnegligible extent, and estimates (albeit highly uncertain) of NO3 reactions for amines in general 

were derived. Methods for estimating rate constants and mechanisms for reactions of amines with 

O3 were also developed. A more complete discussion and documentation of the amine 

mechanisms are given by Carter (2008a).
19

 The ability to represent alkynes was added. The mechanisms for OH reactions were assumed to 

be analogous to that derived for acetylene (Carter et al, 1997c, Carter, 2000a).

 The ability to represent alkylbenzenes and their initial reactions has also been added. However, 

our ability to estimate these reactions has not evolved to the point where this can be used to 

generate reliable mechanisms useful for modeling, and this has been used primarily as a research 

tool in working towards eventually developing more explicit mechanisms for aromatics. This 

work, which is still underway, was useful in deriving the updated condensed mechanisms for 

aromatics discussed later in this section.

The enhanced capabilities required group additivity estimates deriving rate constants for 

additional types of abstraction reactions that were not previously supported, such as abstractions from 

compounds with double bonds, abstractions from aromatics, and abstraction reactions by NO3 radicals 

and Cl atoms. As discussed previously (e.g., see Kwok and Atkinson, 1995 or Carter, 2000a), rate 

constants for abstraction processes can be estimated using

 GroupsSubstituents on Group Total Rate Constant Group Rate Constant Correction Factor

where "group" refers to various parts of the molecule for which group additivity assignments are made. 

Group additivity parameters used for estimating abstraction reactions are given in Table 3. The 

assignments for abstractions by OH are the same as used previously (Carter, 2000a), with assignments for 

reactions of aromatics or amines added as indicated by footnotes to the table. The assignments for the 

NO3 reactions are primarily from Atkinson (1991). The assignments for abstractions by chlorine atoms 

are discussed in the following section.

Support for Chlorine Reactions

As indicated above, in order to support the extension of the mechanism to represent 

chlorine chemistry, the mechanism generation system was enhanced to generate mechanisms for chlorine 

+ VOC reactions. Since the reactions of Cl radicals with VOCs are similar to those of OH. This general 

procedure can be readily adapted to generate mechanisms for Cl + VOC reactions. This requires (1) 

making group-additivity estimates for all the possible initial reactions of Cl with VOCs, (2) generating 

mechanisms for the Cl-containing radicals that can be formed when Cl adds to double bonds, and (3) 

generating mechanisms for the radicals formed. The general procedures are discussed in detail by Carter 

(2000a). The specific adaptations to chlorine atom reactions are discussed below.

Chlorine can react with VOCs either by abstracting a hydrogen atom to form HCl and the 

corresponding alkyl radical, or by adding to a double bond. For abstraction reactions, the rate constants 

can be estimated using group additivity methods, with the rate constant being determined by the sum of 

the abstraction rate constant assigned to the group, multiplied by substituent correction factors for each 

non-hydrogen substituent on the group, summed over all groups with hydrogen atoms (e.g., see Kwok and 

Atkinson, 1995 or Carter, 2000a). Note that the correction factor for methyl substitution is arbitrarily set 

at unity, with the factors for the other substituents being determined based on differences in rate constants 

at groups that are only methyl substituted.
20

Table 3. Group additivity parameters used for estimating rate constants for abstraction reactions 

by OH and NO3 radicals and by Cl atoms.

Table 3a. Abstraction rate constants assigned to groups

Group OH [a] NO3 Cl

k(300) A B D Notes [b] k(300) Notes k(300) Notes

CH3 1.39e-13 4.49e-18 2 320 1,2 7.00e-19 9 3.43e-11 13

CH2 9.41e-13 4.50e-18 2 -253 1,2 1.50e-17 9 6.77e-11 13

CH 1.94e-12 2.12e-18 2 -696 1,2 8.20e-17 9 4.46e-11 13

OH 1.42e-13 2.10e-18 2 85 1,2 0 10 0 10

CHO 1.56e-11 5.55e-12 0 -311 1,3 2.84e-15 [c] 11 6.64e-11 13

HCO(O) 0 1,4 0 10 0 12

OH(O) 5.30e-12 7.82e-17 2 85 5 0 10 0 10

CH3(Bz) [d] 4.92e-13 6 7.00e-19 12 3.43e-11 12

CH2(Bz) [d] 1.88e-12 7 1.50e-17 12 6.77e-11 12

CH(Bz) [d] 1.33e-12 8 8.20e-17 12 4.46e-11 12

CH3(NHx) [e] 1.67e-11 22 ~6.2e-14 24 [f]

CH2(NHx) [e] 1.84e-11 22 ~4.4e-14 24 [f]

CH(NHx) [e] 2.01e-11 23 ~9.9e-14 24 [f]

NH2 1.41e-11 22 ~5.2e-14 24 [f]

NH 3.17e-11 22 ~5.7e-14 24 [f]

[a] Temperature dependences for OH rate constants given by k(T) = A BTexp(-D/T), where T is in oK.

[b] Notes for derivations of the group rate constants and substituent correction factors are given below 

(Note [a] with Table 3b).

[c] The temperature dependence of this group rate constant is given by 1.40e-12 x exp(-1860/T).

[d] "Bz" refers to any aromatic carbon. 

[e] Applicable for x=0,1,2.

[f] Group rate constants for reactions of chlorine with amines were not derived

Table 3b. Group correction factors for abstraction reactions

Group

Substituent Correction Factor

OH NO3 Cl

Factor Note [a] Factor Note Factor Note

CH3 1 1,2,14 1 17 0 14

CHx (x<3) 1.23 1,2 1.34 11 0.95 13

CHx(CO) 3.90 1,2 1.34 17 0.95 17

CHx(CO-O) 1.23 1,2 1.34 17 0.95 17

CHx(Cl) 0.36 1,2 1.34 17 0.19 19

CHx(Br) 0.46 1,2 1.34 17 0.95 17

CHx(F) 0.61 1,2 1.34 17 0.95 17

OH 3.50 1,2 0 18 1.07 13

CHO 0.75 1,2 0.18 11 0.40 13

CO 0.75 1,2 0.89 11 0.04 13

CO(O) 0.31 15 0 12 0.04 17
Table 3 (continued)

Table 3b. Substituent Correction Factors (continued)

21

Group

Substituent Correction Factor

OH NO3 Cl

Factor Note [a] Factor Note Factor Note

CO(OH) 0.74 1,2 0 12 0.04 17

O 8.40 1,2 0 18 1.07 20

O(CO) 1.60 1,2 0 18 1.07 17

O(HCO) 0.90 1,15 0 18 1.07 17

O(NO2) 0.04 1,2 0 18 1.07 17

O(OH) 16.26 5 1 18 1.07 17

NO2 0.00 1,2 0 12 n/a

F 0.09 1,2 0 12 0.01 21

Cl 0.38 1,2 0 12 0.01 13

Br 0.28 1,2 0 12 n/a

I 0.53 1,2 0 12 n/a

C=C 1.00 1,2 1 17 0.95 13

ONO2 0.04 1,2 0 12 0.12

Bz 1 14 1 17 2.03 13

NH2, NH, N 1 14 1 14 [b]

[a] Notes for derivations of the group rate constants and group correction factors are as follows:

1 Same as used in SAPRC-99

2 Kwok and Atkinson (1995)

3 Based on IUPAC (1997) recommendations for acetaldehyde and propionaldehyde

4 Reaction at formate group assumed to be negligible based on tabulated formate rate constants.

5 Derived to fit the NASA (2006) recommended rate constant and branching ratio for reaction of 

OH with methyl hydroperoxide. This results in an unusually large group substituent factor.

6 Average of estimated rate constants per methyl group for the alkylbenzenes for which aromatic 

aldehyde yields have been derived. Reaction at the methyl group is estimated based on the 

aromatic aldehyde yield and the total rate constant.

7 Derived from the difference for the total rate constants for ethylbenzene and toluene, assuming 

the same rate constant for addition to the aromatic ring and the estimated rate constant at the 

methyl group in ethylbenzene.

8 Derived from the difference for the total rate constants for isopropyl benzene and toluene, and pcymene and p-xylene, assuming the same rate constant for addition to the aromatic ring and the 

estimated rate constants for reactions at the methyl groups in isopropyl benzene and p-cymene.

9 From Atkinson (1991). Derived from the correlation between NO3 and OH radical rate constants.

10 Assumed to be negligible.

11 Derived from the IUPAC (1997) recommended rate constant for acetaldehyde.

12 No explicit assignment made. By default, the system uses the same assignment as for standard 

CH3, CH2, or CH groups.

13 Derived in this work from measured chlorine + VOC rate constants. See text and Table 4

14 Assigned.

15 From Kwok et al (1996).

16 Adjusted to fit OH + ethyl and propyl formate rate constants (Wallington et al, 1988b)
22

17 No assignment made. This is the default value used by the mechanism generation system, and 

may not be appropriate.

18 This is the assignment incorporated into the current system. It may not be appropriate. It is not 

used as the basis for estimating NO3 rate constants for any detailed model species.

19 Based on chloroacetaldehyde only

20 Estimated to be approximately the same as the factor for OH.

21 Estimated to be approximately the same as the factor for Cl.

22 Derived to give the best fits to the available kinetic data for simple amines and alcohol amines for 

which kinetic data are available, as indicated in Table 3c. In order to fit the data for tertiary

amines, it is necessary to assume that OH reacts with an enhanced rate at groups next to the 

amino group, and in order to fit the data for amines, such as AMP and t-butyl amine, that do not 

have abstractable hydrogens next to the amino group it is necessary to assume that reaction also 

occurs at a significant rate at the NH or NH2 groups.

23 No data are available for which to derive group-additivity estimates for this type of group. The 

group rate constant is estimated by linear interpolation from those used for CH3(NHx) and 

CH2(NHx).

24 The only kinetic data concerning the reactions of NO3 radicals with amines is for N-methyl-2-

pyrrolidinone (NMP), where a relatively high rate constant of 1.26 x 10-13 cm3 molec-1s

-1

is 

measured (Aschmann and Atkinson, 1999). This suggests that this reaction is also rapid for other 

amines. We assume that this is an H-atom abstraction reaction, forming HNO3. For lack of other 

data, use the rate constant for NMP as the basis for estimating the group rate constants for 

reaction at the -CH2(N) or CH3(N) groups. The group rate constants for reactions at other amine 

groups, including NH and NH2, are estimated assuming that the ratios of rate constants for 

reactions at the various groups are the same for the NO3 reaction as derived for the OH reaction. 

This is highly uncertain.

[b] Group rate constants for reactions of chlorine with amines were not derived

Table 3c. Experimental and best fit estimated rate constants for the reactions of OH radicals with 

amines that were used as the basis for deriving structure-reactivity estimates

Compound OH Rate Constant (10-11 cm3 molec-1

s

-1

)

Measured value, reference Avg Calc Diff

Methyl amine 1.73 1 2.20 2 1.97 3.08 36%

Dimethyl amine 6.49 1 6.54 3 6.52 6.51 0%

Trimethyl amine 3.58 1 6.09 3 4.84 5.01 4%

Ethyl amine 2.38 1 2.77 3 2.58 3.59 28%

N,N-Dimethylethanolamine (DMAE) 9.00 4 4.70 5 6.85 6.02 -14%

t-Butyl amine 1.18 6 1.18 1.79 34%

2-Amino-2-methyl-1-propanol (AMP) 2.80 5 2.80 2.19 -28%

References for measured rate constants:

1 Carl and Crowley (1998) 4 Anderson and Stephens (1988)

2 Atkinson et al. (1977) 5 Harris and Pitts (1983)

3 Atkinson et al. (1978) 6 Koch et al (1996)
23

For addition to double bonds, we assume that the rate constant is determined only by the 

number of non-hydrogen substituents about the double bond, with correction factors used for some nonalkyl substituents such as halogens. Although this doesn't affect the rate constant, for the purpose of 

estimating mechanisms it is also necessary to assign factors for the fractions that react at each position 

around the double bond. This has to be estimated because we are aware of no data available concerning 

this.

The organic + Cl atom rate constants that were used as the basis for deriving group-additivity

estimates for the mechanism generation system are given in Table 4, with footnotes indicating the sources 

of the rate constants used. (Note that the rate constants in Table 4 are restricted to those used for deriving 

the group-additivity methods, and does not include compounds for which the estimation method was not 

developed to support. See Table B-7 for the chlorine atom rate constants for all the VOCs in the 

mechanism.) Group additivity parameters found to give the best fits to the data on Table 4 are shown on 

Table 3, above, for the abstraction reactions, and on Table 5 for reactions at double bonds. The "Est'n 

error" column on Table 4 shows the extent to which the estimated rate constant agrees with the measured 

value, with positive numbers indicating overprediction, and vise-versa. If there is no entry in this column 

it means that the current estimation method is not applicable to those compounds. The group additivity 

parameters were determined by minimizing the sum-of-square relative errors in for the compounds listed 

on Table 4. In most cases the estimated rate constants agree with the measured values to better than 25%. 

However, cases with prefect agreement usually indicate that a parameter was determined only by the data 

for a single compound, so perfect agreement is not always evidence for the success of the method.

The Cl abstraction reactions form the same radicals as the corresponding reactions with 

OH, so the procedures for generating the subsequent reactions of those radicals formed have already been 

developed and described (Carter, 2000a). Therefore, for VOCs for which only the abstraction reaction is 

important, which include all saturated VOCs and also simple aldehydes, ketones, and esters, the derived 

mechanisms for the chlorine reactions are the same as those for the reaction with OH, except for the 

different branching ratios for the initial reactions because of the differences in the group additivity 

parameters, discussed above.

Although in principle the system could also derive mechanisms for the reactions of 

chlorine atoms with alkenes, in practice this proved difficult because at present the system does not 

contain the necessary thermochemical or kinetic assignments to estimate reaction rates for many of the 

chlorine-substituted alkoxy radicals predicted to be formed. The only way to deal with this is to make 

explicit assignments of branching ratios for the Cl-substituted radicals that cannot presently be handled by 

the system, which can be time consuming for large molecules because of the number of radicals that can 

be formed. For that reason, assignments were made only to permit the generation of mechanisms for the 

explicitly represented alkenes (ethylene and isoprene), those chosen as representative of the lumped 

model species used in airshed models (discussed later in this report), or those present in the chamber 

experiments relevant to evaluating mechanisms for the chlorine-containing compounds for which 

chamber data are available.

The alkoxy radical branching ratio assignments used to generate the chlorine + alkene 

mechanisms that were derived for this project are summarized on Table 6, with footnotes giving a brief 

indication of the basis of the assignments. In addition, except as indicated on Table 6, it is assumed that 

-chloro-alkoxy radicals predominantly decompose to form chlorine atoms, e.g., 

ClCH2O·  HCHO + Cl·

RCH(Cl)O·  RCHO + Cl·

RC(R')(Cl)O·  RC(O)R' + Cl·
24

Table 4. Rate constants for reactions with chlorine atoms for organic compounds used to derive 

parameters for group-additivity estimates.

Compound

Rate Constant Assignment [a] Note

[b]

Est'n 

k(298) A Ea (deg K) Error [c]

Methane 1.03e-13 6.60e-12 1240 1

Ethane 5.93e-11 8.30e-11 100 1 15%

Propane 1.37e-10 1.20e-10 -40 2 -3%

n-Butane 2.05e-10 2.05e-10 0 1 -5%

n-Pentane 2.80e-10 2 -8%

n-Hexane 3.40e-10 2 -6%

n-Heptane 3.90e-10 2 -3%

n-Octane 4.60e-10 2 -4%

n-Nonane 4.80e-10 2 5%

n-Decane 5.50e-10 2 3%

Isobutane 1.43e-10 2 0%

Neopentane 1.11e-10 1.11e-10 0 2 18%

Iso-Pentane 2.20e-10 2 -7%

2,3-Dimethyl Butane 2.30e-10 2 -6%

2-Methyl Pentane 2.90e-10 2 -8%

3-Methylpentane 2.80e-10 2 -4%

2,2,3-Trimethyl Butane 2.90e-10 2 -29%

2,4-Dimethyl Pentane 2.90e-10 2 -4%

2-Methyl Hexane 3.50e-10 2 -6%

2,2,3,3-Tetramethyl Butane 1.75e-10 2 12%

2,2,4-Trimethyl Pentane 2.60e-10 2 3%

Cyclohexane 3.50e-10 2 6%

Methylcyclohexane 3.90e-10 2 -2%

Propene 2.67e-10 4 -1%

1-Butene 3.39e-10 5 -3%

1-Pentene 4.05e-10 5 -4%

3-Methyl-1-Butene 3.52e-10 6 -4%

3-Methyl-1-Pentene 3.78e-10 6 6%

Isobutene 3.25e-10 6 9%

2-Methyl-1-Butene 3.82e-10 6 10%

cis-2-Butene 3.88e-10 6 -15%

trans-2-Butene 3.55e-10 4 -7%

2-Methyl-2-Butene 3.23e-10 6 7%

Cis 4-Methyl-2-Pentene 4.04e-10 6 0%

Toluene 6.20e-11 7 12%

m-Xylene 1.35e-10 7 3%

o-Xylene 1.40e-10 7 -1%

p-Xylene 1.44e-10 7 -4%

1,3,5-Trimethyl Benzene 2.42e-10 8 -14%

Methanol 5.50e-11 5.50e-11 0 1 -34%

Ethanol 1.00e-10 8.60e-11 -45 1 5%

Isopropyl Alcohol 8.60e-11 1 31%

n-Propyl Alcohol 1.62e-10 2.50e-10 130 1 3%

Acetic Acid 2.65e-14 1 0%

Acetaldehyde 8.00e-11 8.00e-11 0 1 0%

Propionaldehyde 1.23e-10 9 0%

Acetone 2.69e-12 7.70e-11 1000 10 0%

Methyl Ethyl Ketone 3.60e-11 1 2%

Methyl Chloride 4.89e-13 2.17e-11 1130 10 -7%

Dichloromethane 3.49e-13 7.40e-12 910 10 11%
Table 4 (continued)

25

Compound

Rate Constant Assignment [a] Note

[b]

Est'n 

k(298) A Ea (deg K) Error [c]

Chloroform 1.19e-13 3.30e-12 990 10 -7%

Vinyl Chloride 1.27e-10 11 4%

1,1-Dichloroethene 1.40e-10 11 -19%

Trans-1,2-Dichloroethene 9.58e-11 11 8%

Cis-1,2-Dichloroethene 9.65e-11 11 7%

Trichloroethylene 8.08e-11 11 -18%

Perchloroethylene 4.13e-11 11 9%

3-Chloropropene 1.30e-10 12 0%

Chloroacetaldehyde 1.29e-11 13 0%

[a] Rate constants and A factors in units of cm3 molec-1s

-1

. If no A factor or activation 

energy is given, rate constant is given only for 298K. Otherwise, 298K rate constant 

is calculated from A factor and activation energy.

[b] Notes:

1 IUPAC (2006) recommendation.

2 Atkinson (1997) recommendation.

3 This reaction is in the pressure falloff region under atmospheric conditions.

4 Average of values tabulated by Wang et al (2002). Value of Wang et al (2002) 

placed on an absolute basis using the Atkinson (1997)-recommended rate 

constant for n-heptane.

5 Average of value of Coquet et al (2000), placed on an absolute basis using the 

Atkinson (1997)-recommended n-hexane rate constant, and the value of Wang et 

al (2002), placed on an absolute basis using the Atkinson (1997)-recommended 

rate constant for n-heptane.

6 Value of Wang et al (2002), placed on an absolute basis using the Atkinson 

(1997)-recommended rate constant for n-heptane.

7 Average of values tabulated by Wang et al (2005).

8 Wang et al (2005).

9 Average of values listed by Le Crane et al (2005)

10 NASA (2006) recommendation.

11 From rate constants relative to n-butane from Atkinson and Aschmann (1987), 

placed on an absolute basis using the n-butane rate constant recommended by 

IUPAC (2006).

12 Average of values tabulated by Albaladejo et al (2003).

13 Average of values tabulated by Scollard et al (1993)

[c] (Estimated rate constant - measured rate constant) / measured rate constant.
26

Table 5. Group additivity rate constants and factors used for estimating rates of addition of Cl 

atoms to double bonds.

Group k(add) Add'n to most 

substituted end Note Group Substituent Correction Note

CH2=CH- 2.30e-10 35% 1,2 Alkyl 1 3

CH2=C< 2.89e-10 25% 1,4 -Cl 0.58 1

-CH=CH- 2.63e-10 50% 1,5 2 -Cl's 0.68 1

-CH=C< 2.47e-10 25% 1,4 -CH2Cl 0.56 1,6

>C=C< 2.47e-10 50% 1,5

1 Addition rate constant and substituent correction factor derived to minimize sum of 

squares error in predictions of Cl + alkene rate constants. (Optimization for group 

additivity parameters for abstraction reaction carried out at the same time.)

2 Assume same terminal bond addition fraction as used for the reaction of OH with 

propene (Carter, 2000a).

3 All alkyl substituents assumed to have the same factor. Unit factor assigned.

4 No information available concerning relative addition rates at the different positions. 

Assume addition at terminal position occurs about 25% of the time

5 Assume equal probability of addition, regardless of substituents.

6. Based on rate constant for 3-chloropropene.

These assignments, and therefore the mechanisms derived for the chlorine + alkene reactions that are 

based on them, are uncertain. However, reactions of alkenes with chlorine atoms are generally not major 

sinks either for chlorine or alkenes under most conditions, so these assumptions are probably not major 

sources of uncertainty in terms of overall model predictions.

Updates to Rate Constants and Mechanisms

Because of time and resource limitations, we were not able to update most of the 

estimation methods incorporated in the SAPRC-99 mechanism generation system used for this project, so 

most of the various estimation assignments given by Carter (2000a) are still applicable for this version. 

However, we did update the assignments for the rate constants for the initial reactions of the individual 

VOCs in those cases where rate constant measurement data are available, and these were used when 

generating the mechanisms for the applicable VOCs. Table B-2, and Table B-4 through Table B-6 and 

their footnotes indicate the rate constants used and the sources of those rate constants, where applicable.

Based on results of recent evaluations and also results the evaluation against chamber 

data, some updates were also made to assigned reactions of excited Criegee radicals involved in the ozone 

+ alkene reactions. The current assignments for Criegee biradical reactions are summarized on Table 7. 

Note that the amount of radical formation in the decomposition of the primary biradicals, which was 

adjusted based on simulations of chamber data, is somewhat higher than used in the SAPRC-99 

mechanism, but still lower than currently recommended radical yields for these reactions. This 

inconsistency, which is also seen in evaluations of the MCM, is discussed further by Pinho et al (2006).

Additional updates or modifications were made for mechanisms of some individual 

VOCs, based primarily on results of model simulations of chamber experiments. For example, the 

mechanism for the reaction of O

3

P with ethene was updated based on the Calvert et al. (2000) 
27

Table 6. Branching ratio assignments for chlorine-substituted alkoxy radicals made to generate 

mechanisms for the reactions of chlorine with representative alkenes. 

Used for Reaction Fract. Notes

Propene CH3CH(O·)CH2Cl + O2  CH3C(O)CH2Cl + HO2· 100% 1

CH3CH(CH2O·)Cl + O2  CH3CH(CHO)Cl + HO2· 100% 2

2-Butenes CH3CH(O·)CH(CH3)Cl + O2  CH3C(O)CH(CH3)Cl + HO2· 100% 3

1-Pentene CH3CH2CH2CH(O·)CH2Cl  ·CH2CH2CH2CH(OH)CH2Cl 100% 4

CH3CH2CH2CH(CH2O·)Cl  CH3CH(·)CH2CH(Cl)CH2OH 100% 4

CH3CH(O·)CH2CH(Cl)CH2OH  CH3CH(OH)CH2CH(Cl)CH(·)OH 100% 4

2-Pentenes CH3CH2CH(O·)CH(CH3)Cl  CH3CH2CHO + CH3CH(·)Cl 100% 5

CH3CH2CH(Cl)CH(O·)CH3  CH3CHO + CH3CH2CH(·)Cl 100% 5

Isoprene CH2=C(CH3)CH(·)CH2Cl + O2  CH2=C(CH3)CH(OO·)CH2Cl 60% 6

  CH3C(CH2OO·)=CHCH2Cl 41%

CH2=CH-C(·)(CH3)CH2Cl + O2  CH2=CH-C(OO·)(CH3)CH2Cl 44% 6

  CH3C(=CH-CH2OO·)CH2Cl 56%

CH2=C(CH3)CH(O·)CH2Cl + O2  CH2=C(CH3)C(O)CH2Cl + HO2· 100% 7

CH3C(=CH-CH2O·)CH2Cl + O2  CH3C(CH2Cl )=CHCHO + HO2· 100% 8

CH3C(CH2O·)=CH-CH2Cl + O2  CH3C(CHO)=CHCH2Cl + HO2· 50% 9

  CH3C(CH2OH)=CH-CH(·)Cl 50%

CH2=CH-C(O·)(CH3)CH2Cl  CH2=CHC(O)CH3 + .CH2Cl 100% 5

CH2=C(CHO)CH2O· + O2  CH2=C(CHO)CHO + HO2· 100% 10

CH2=C(CH3)CH(CH2O·)Cl + O2  CH2=C(CH3)CH(CHO)Cl + HO2· 50% 9

  CH2=C(CH2·)CH(Cl)CH2OH 50%

CH2=C(CH2O·)CH(Cl)CH2OH  CH2=C(CH2OH)CH(Cl)CH(·)OH 50% 9

 + O2  CH2=C(CHO)CH(Cl)CH2OH + HO2· 50%

CH2=CH-C(CH3)(CH2O·)Cl + O2  CH2=CH-C(CH3)(CHO)Cl + HO2· 100% 10

-Pinene CH3C(O·)*1CH(Cl)CH2CH*2CH2CH*1C*2(CH3)CH3  CH3C(O)CH(Cl)-

CH2CH*1CH2CH(·)C*1(CH3)CH3

100% 4,11

CH3C(O)CH(Cl)CH2CH(O·)CH2CHO  HCOCH2CHO + CH3C(O)-

CH(CH2·)Cl

100% 5

CH3C(O)CH(CH2O·)Cl  ·CH2C(O)CH(Cl)CH2OH 100% 4

.OCH2C(O)CH(Cl)CH2OH  HOCH2C(O)CH(Cl)CH(·)OH 100% 4

CH3C*1(Cl)CH(O·)CH2CH*2CH2CH*1C*2(CH3)CH3  CH3C(·)(Cl)CH*1-

CH2CH(CH2CHO)C*1(CH3)CH3

100% 4,11

2-(Chloromethyl)-3-chlororopene

ClCH2C(O·)(CH2Cl)CH2Cl  ClCH2C(O)CH2Cl + .CH2Cl 100% 12

·OCH2C(Cl)(CH2Cl)CH2Cl + O2  HCOC(Cl)(CH2Cl)CH2Cl + HO2· 100% 10

1,3-Dichloropropenes

ClCH2CH(O·)CH(Cl)Cl + O2  Cl-CH2C(O)CH(Cl)Cl + HO2· 100% 13

1 Assumed to be favored over decomposition on the basis of estimates for CH3C(O·)CH3 and the 

expectation that Cl-substitution makes radicals less stable

2 Assumed to be favored over decomposition on the basis of estimates for CH3CH2CH2O· and the 

expectation that Cl-substitution makes radicals less stable

3 Assumed to be favored over decomposition on the basis of estimates for the radical where H- replaces 

Cl- and the expectation that Cl-substitution makes radicals less stable

4. Isomerization is assumed to dominate over competing processes for this radical.
Table 6 (continued)

28

5 This decomposition is assumed to dominate based on estimates for similar radicals.

6 Branching ratios based on the mechanism of Fan and Zhang (2004)

7 Assumed to be fast on the basis of observation of this compound as a product in the isoprene -

chlorine reactions.

8 Although isomerizations might be expected to be more important than O2 reaction, this is assumed to 

dominate to account for the observed formation of CMBA as a product in the isoprene + chlorine 

reactions.

9 Reaction with O2 is assumed to be the dominant product when the radical is in the trans configuration, 

and isomerization is assumed to be the dominant process when it is in the cis configuration. Equal 

possibility of cis and trans configuration is assumed.

10 It is expected that the competing decomposition isn't favorable, so the reaction with O2 is assumed to 

dominate. However, this is uncertain.

11 The "*1" and "*2" symbols indicate join points for these cyclic radicals.

12 This appears to be the only available reaction.

13 Assumed to be favored over decomposition on the basis of estimates for CH3C(O·)CH3 and the 

expectation that Cl-substitution makes radicals less stable

recommendation, but it was still necessary to assume lower fragmentation yields than recommended in 

order to simulate the chamber data, as was the case for the reactions of O

3

P with other alkenes (Carter, 

2000a; Pinho et al, 2006). Overall nitrate yields that were derived based on simulations of chamber data 

had to be readjusted for a number of compounds because changes to the base mechanism apparently

caused the values of the nitrate yields that best fit the data to change somewhat. Assignments are made to 

the mechanism generation system to implement these adjustments where applicable.

Adjusted Product Mechanisms

Although the mechanism generation system derives fully explicit mechanisms, by default it 

lumps all the reactive products predicted to be formed into the set of organic product model species in the 

base mechanism, as indicated on Table A-1 in Appendix A. The mechanisms so derived are given in 

Table B-3 in Appendix B. Because the mechanisms used for the product species are fixed regardless of 

what VOC is being represented, these are referred to as "fixed product" mechanisms in the subsequent 

discussion. However, lumping the many types of reactive products into a few model species is an 

approximation, and some VOCs may form products that are not particularly well represented by any of 

the generic product model species. This could introduce inaccuracies to calculations of atmospheric 

reactivity scales. For this reason the mechanism generation system is also capable of deriving 

mechanisms for the major reactive products of the VOCs that could be used "adjustable product" 

mechanisms where the more reactive product species are represented by lumped (or explicit) product 

species whose mechanisms were derived based on the distribution of products they are being used to 

represent. Note that these adjustable mechanism products are only used on the mechanism for the 

particular VOC in the reactivity calculations, not for mechanisms of other VOCs in the base mechanism. 

The derivation and implementation of these adjustable product mechanisms is discussed by Carter et al 

(2000a). Since the same procedures were used for deriving the adjustable product mechanisms in this 

work, they are not discussed further here.
29

Table 7. Assigned mechanisms for Crigiee Biradicals used for deriving mechanisms for reactions 

of O3 with alkenes.

Reaction Fraction Discussion

H2COO[excited]  Branching ratios based on recommendations by 

Atkinson (1997), modified to be consistent with the 

OH yield in the IUPAC (2006) recommendations

H2COO[stab] 37%

HCO + OH 16%

CO2 + H2 12%

CO + H2O 35%

CH3CHOO[excited]  Atkinson (1997) recommendation.

CH3CHOO[stab] 15%

CH3· + CO + OH 54%

CH3· + CO2 + H 17%

CH4 + CO2 14%

RCX(X')CXOO[excited]  (R=Alkyl other than CH3; X, X' = H or alkyl): 

Available data concerning stabilization and 

decompositions of RCHOO Criegee biradicals are 

limited and inconsistent. In order to fit chamber data to 

fit results of 1-butene and 1-hexene experiments, it is 

necessary to assume that stabilization occurs ~85% of 

the time for 4+-carbon Criegee biradicals.

RCX(X')CXOO[stab] 85%

RCX(X')· + CO + OH 9.5%

RCX(X')· + CO2 + H 3.0%

RCHXX' + CO2 2.5%

XCX'H-COO[excited]-R  (X, X' = H or alkyl; R = alkyl): OH formation after 

hydroperoxide rearrangement assumed to be dominant 

process for disubstituted Criegee biradicals based on 

high OH yields, as discussed by Atkinson (1997). 

Relative importance of competing rearrangements 

estimated to be approximately proportional to 

estimated OH abstracting rate constant from Hdonating group. (Unchanged from SAPRC-99)

·CXX'-CO-R + OH 100%

Rt-COO[excited]-Rt'  (Rt = tertiary alkyl): Most reasonable decomposition 

mode is formation of CO2 and radicals. No information 

about reactions of disubstituted Criegee biradicals that 

cannot undergo the hydroperoxide rearrangement. 

Roughly estimate that most is stabilized. The 

decomposition fraction is a guess. It probably depends 

on size of the molecule, but this is not taken into 

account. (Unchanged from SAPRC-99)

Rt-COO[stab]-Rt' 90%

Rt· + Rt' + CO2 10%
30

Adjustable product mechanisms were derived for all VOCs whose reactions and product reactions 

could be completely generated using the mechanism generation system. To assess the effects of using 

adjustable product mechanisms on calculated atmospheric incremental reactivities, Figure 1 shows a 

comparison of incremental reactivities calculated for the "averaged conditions MIR scale" calculated 

using the two methods for all VOCs for which adjustable product mechanisms could be derived. 

[Incremental reactivity scales are discussed in the "Updated Reactivity Scales" section, below. Briefly, the 

Averaged Conditions MIR scale gives a good approximation of the MIR scale used in CARB regulations 

(CARB 1993, 2000) using a single scenario rather than the average of 39 MIR scenarios.] It can be seen 

that for most VOCs the adjustable mechanism reactivities are very close to the fixed mechanism values, 

with the average bias being -1% and the average error being 6%1. However, there were a number of 

compounds with non-negligible differences where use of the adjustable product mechanisms for reactivity 

calculations is appropriate. The compounds where the magnitude of the change was greater than 20% are 

listed in Table 8, with the reasons for the differences indicated for the top three compounds.

For the purpose of calculating reactivity scales, we used the adjustable product mechanism if the 

calculated reactivity difference in the averaged conditions MIR scale was greater than 8%, and the fixed 

product mechanism otherwise. The use of 8% is somewhat arbitrary, but given the uncertainties in 

mechanisms in general, and product mechanisms derived using the mechanism generation system in 

particular, we did not consider the added complexity to be appropriate if the effect of less than 

approximately this amount. Table B-3 in Appendix B gives the adjustable product mechanisms that were 

employed in the reactivity scale calculations as determined by this criterion. Note that the primary VOC 

rate constants and methods for deriving the mechanisms are the same as indicated in Table B-2 for the 

fixed parameter mechanism, so this documentation is not duplicated on this table. If the mechanism for a

 

1 The average bias is calculated as the average relative difference, while the average error is the average 

of the absolute magnitude of the relative difference.
31

Figure 1. Effect of using the adjustable product mechanisms vs. the standard fixed product 

mechanisms on incremental reactivities in the "Averaged Conditions" MIR scale for 

those VOCs for which adjustable product mechanisms could be derived.

Table 8. Compounds whose Averaged Conditions MIR reactivities changed by more than 20% 

when adjustable product mechanisms were employed.

Compound

Averaged Conditions MIR 

(gm O3 / gm VOC) Discussion

Fixed Adj'd Diff

2,3-Butanediol 2.51 4.41 75% High yield product reacts to form biacetyl

1,2-Dihydroxy hexane 2.01 2.54 26% Products react to form methyl glyoxal

Dimethoxy methane 1.25 0.93 -26% Product represented by PROD2 has a relatively 

low rate constant for this group

cis-5-Decene 2.96 3.73 26%

Glycerol 2.53 3.17 25%

4-Methyl-2-pentanol 2.15 2.61 21%

cis-4-Octene 3.94 4.79 22%

VOC is not given in Table B-3, the mechanism used in Table B-2 was used to calculate its reactivity. The 

reactivity listings on Table B-1 in Appendix B indicate those cases where adjustable products 

mechanisms were used.

Updated Aromatics Mechanisms

Although significant progress has been made in recent years concerning the atmospheric reactions 

of aromatics and their reactive products (e.g., Calvert et al, 2002, Barnes, 2006, and references therein), 

the aromatics continue to represent the major class of compounds for which insufficient information 

exists for deriving predictive and explicit mechanisms based on mechanistic considerations alone. The 

most important uncertainties concern the reactions of the aromatic ring fragmentation products, which 

0.1

1

10

0.1 1 10

Fixed Product Reactivity

(gm O3 / gm VOC)

Adjustabe product reactivity

Compounds

1:1 Line

0

50

100

150

200

< -25%

-25% - -15%

-15% - -5%

-5% - 5%

5% - 15%

15% - 25%

> 25%

Range of Difference

Number of V

O

Cs
32

include highly photoreactive compounds that make significant contributions to overall aromatic reactivity. 

SAPRC-99 mechanism incorporates a highly simplified and parameterized set of model species to 

represent these products, whose yields and photolysis rates are adjusted to fit chamber data. In addition, 

the mechanisms for the reactions of ring-retaining products such as phenols, cresols, and nitrophenols are 

also highly uncertain, and SAPRC-99 uses simplified and parameterized representations for these 

reactions as well. Other mechanisms currently used in airshed models (Gery et al, 1988, Yarwood et al, 

2005; Stockwell et al, 1990, 1997) also incorporate simplified and parameterized representations of 

aromatics, and although the MCM incorporates an attempt at a more explicit aromatics representation, its 

performance in simulating available environmental chamber data is so poor that it is not suitable for 

airshed modeling (Bloss et al, 2005).

The uncertain parameters in the SAPRC-99 aromatics mechanisms were optimized to give 

reasonably good simulations of results of aromatics - NOx and environmental chamber experiments, and 

the mechanisms so derived also gave generally satisfactory results of incremental reactivity experiments 

with aromatics (Carter, 2000a), including some experiments carried out after the SAPRC-99 mechanism 

was developed at lower NOx concentrations in the new UCR EPA chamber (Carter, 2004). However, 

Carter (2004) also found that the SAPRC-99 mechanism consistently underpredicts the extent of ozone 

enhancement caused by adding CO to aromatics - NOx irradiations, Carter and Malkina (2002) found that 

the mechanism overpredicts "direct reactivity" in experiments designed to be sensitive to the direct effects 

of the primary reactions of aromatics on NO to NO2 conversions. This suggests that there may be 

compensating errors in the SAPRC-99 aromatics mechanisms. In addition Carter (2004) found that 

SAPRC-99 (and also CB4) tends to underpredict ozone formation in at low ROG/NOx ratios and low NOx

concentrations in Surrogate - NOx experiments when the surrogate contains aromatics, but this is not seen 

in surrogates where the aromatics have been removed (unpublished results from this laboratory – also see 

"Mechanism Evaluation" section, below). Because of these problems, updating and improving the 

aromatics mechanisms was an important priority for this project.

The approach that was initially attempted to derive updated aromatics mechanisms was to derive 

fully (or at least nearly) explicit mechanisms for representative aromatic hydrocarbons and their oxidation 

products, and use these as a basis for deriving more condensed mechanisms that can be used for 

representing aromatics in general. However, this turned out to be unworkable in practice, at least within 

the time and resource constraints for this project. Developing fully explicit mechanisms that are entirely 

consistent with available data as given by Calvert et al (2002) is not possible because the low and 

inconsistent measured product yields can not account for complete reaction pathways, and mechanisms 

based on some of the data could not be made to give predictions that were consistent with the available 

environmental chamber reactivity data. This was found to be the case both for the initial aromatic ringopening reactions, where yields of the expected unsaturated dicarbonyl ring-opening products were found 

to be low, and the photolysis reactions of the unsaturated dicarbonyl products, where assuming relatively

high yields of non-radical products gave mechanisms that significantly underpredicted aromatic 

reactivities in chamber experiments. Also, mechanism incorporating new product data for phenols and 

cresols (Barnes, 2006; Berndt and Boge, 2003, Olariu et al, 2002) gave predictions that were inconsistent 

with the limited chamber data and therefore could not be used.

The approach that was therefore adopted for this version of the mechanism is to use a simplified 

but consistent and chemically reasonable model for the initial ring fragmentation reactions that give 

improved simulations of the direct reactivity data of Carter and Malkina (2002), and derive new 

mechanisms for the model species used to represent the unknown or uncertain aromatic ring 

fragmentation products based on estimated mechanisms for representatives of the unsaturated 1,4- and 

1,6-dicarbonyls expected to be formed. The only adjustable parameters employed concerned the ratio of 

photoreactive to un-photoreactive model species representing the unsaturated 1,4-dicarbonyls, which were 

adjusted to fit the data for the aromatics - NOx experiments for the individual compounds. This yielded 

mechanisms that performed as well as SAPRC-99 in simulating aromatics - NOx and aromatics 
33

incremental reactivity experiments, and that performed somewhat better in simulating the direct reactivity 

results of Carter and Malkina (2002). However, the problem of underpredicting the effects of adding CO 

to aromatics - NOx irradiations and underpredicting O3 formation in surrogate - NOx experiments at low 

NOx and low ROG/NOx conditions remained. Therefore, although the updated mechanisms are probably 

more chemically reasonable and consistent with somewhat more of the available data than was the case 

previously, not all of the problems could be resolved.

Reactions of Alkylbenzenes with OH

The major initial atmospheric reaction of aromatics is with OH radicals. Table 9 gives the 

measured or estimated product yields for the known products for the OH radical reaction that are used as 

the bases for the aromatics mechanisms developed in this work, with footnotes indicating the sources of 

these yields. The initial reactions can either be abstraction of H from side groups off the ring, or OH 

addition to the aromatic ring. The fractions reacted at the various positions, and their subsequent 

mechanisms, are derived as described below.

Reactions off the Aromatic Ring. The reactions following abstraction from the groups off 

the ring are exactly analogous to those in the alkane photo-oxidation system, and are assumed to proceed 

as shown below for toluene
34

Table 9. Measured or estimated yields of known products for benzene and methylbenzene 

reactions that were incorporated in the SAPRC-07 aromatics mechanisms

Compound

Yields and Notes [a]

Aromatic 

Aldehyde

Phenol or 

Cresol Glyoxal Methyl Glyoxal Biacetyl Nitrate yield [b]

Benzene 57% [1] 29% [2] 7.7% [3]

Toluene 6.5% [4] 18% [5] 24% [6] 15% [7] 10.6% [8]

Xylenes 13.6% [3]

o- 4.7% [9] 16% [10] 8.4% [11] 24% [11] 19% [12]

m- 4.1% [13] 16% [14] 10% [15] 38% [16]

p- 8.8% [17] 16% [18] 29% [19] 11% [20]

Trimethylbenzenes 16.2% [3]

1,2,3- 4.5% [21] 3.1% [22] 7.2% [23] 18% [23] 45% [24]

1,2,4- 3.6% [25] 2.2% [26] 7.4% [27] 41% [28] 11% [29]

1,3,5- 3.0% [30] 4.0% [31] 64% [34]

[a] Footnotes giving the sources of the assignments are as follows. Italic indicates estimated values.

1 Average of values of Berndt and Boge (2006) and Volkamer et al (2002).

2 The yields of Berndt and Boge (2006), which are reasonably consistent with previous studies 

(Calvert et al, 2002), are used.

3 Estimated based on carbon number and the nitrate yield derived for toluene as discussed in the 

text and shown on Figure 3.

4 Yields tabulated by Calvert et al (2002) range from 5-12%. Value used is average of data from 

studies published since 1989, which tend to be reasonably consistent as a group. This is lower 

than the 8.5% used in SAPRC-99

5 Total of yields for individual isomers from Calvert et al (2002)

6 Data tabulated by Calvert et al (2002) indicate a range of yields, from 4-24%, with Volkamer and 

co-workers (Volkamer, personal communication) reporting 35%. We tentatively use the value of 

Smith et al (1998), which is the highest tabulated by Calvert et al (2002) but still lower than the 

Volkamer value. The methyl glyoxal yield reported by Smith et al (1998) are in good agreement 

with the value used, which tends to support use of their data. Also, the mechanism estimation 

system estimates higher yields of glyoxal than methyl glyoxal will be formed from toluene.

7 Data tabulated by Calvert et al (2002) indicate a range of yields, but a number of recent studies 

are reasonably consistent in indicating yields of ~15%. The average of the data from the studies 

with the higher yields is used.

8 Derived from the ratio of the benzyl nitrate to the benzaldehyde yield as discussed in the text. 

Assumed that the same ratio is applicable to the other peroxy radicals in the toluene photooxidation system.

9 Most of the recent o-tolualdehyde yield data tabulated by Calvert et al (2002) are around 5%, and 

the value used is the average of those studies. A few studies indicate higher yields, but these are 

not used in computing the average.

10 The total dimethylphenol yields of Atkinson et al (1991) are used because they were conducted at 

the lowest NOx levels.

11 The data of Bandow and Washida (1985a) and Tuazon et al (1986) are in good agreement, and 

the average is used. The low value of Shepson et al (1984) is not used.

12 The low NOx limit value of Atkinson and Aschmann (1994) is used. It is reasonably consistent 

with data from other studies at lower NOx levels tabulated by Calvert et al (2002).
Table 9 (continued)

35

13 Most of the recent o-tolualdehyde yield data tabulated by Calvert et al (2002) are around 5%, and 

the value used is the average of those studies. A few studies indicate higher yields, but these are 

not used in computing the average.

14 Average of the total dimethylphenol data reported by Atkinson et al (1991) and Smith et al 

(1999). However, these two studies are not in particularly good agreement on yields for the 

individual isomers. The total is consistent with the value used for o-xylene.

15 Average of the data tabulated by Calvert et al (2002). There is not particularly agreement among 

the studies, but there are no obvious outliers.

16 Average of the data tabulated by Calvert et al (2002), excluding the low value of Tuazon and coworkers which is superceded by a more recent measurement from the same group.

17 Average of the various measurements tabulated by Calvert et al (2002). There is not particularly 

good agreement, but no obvious outliers to exclude from the average.

18 Average of 2,5-dimethylphenol yields of Atkinson et al (1991) and Smith et al (1999). Yields 

reported by Becker et al (1997) are lower and not used.

19 Average of yields reported by Bandow and Washida (1985a), Tuazon et al (1986) and Smith et al 

(1999).

20 The data tabulated by Calvert et al (2002) show some variation, but three studies give good 

agreement and indicate yields of about 10%. The value used is the average from those studies.

21 No data available. Estimated from the average rate constant per methyl group for the other 

methylbenzenes and the total OH rate constant.

22 No data available. The average of the assigned phenolic product yield for the other 

trimethylbenzenes is used.

23 The yields determined by Bandow and Washida (1985b) are used for consistency with 

assignment for biacetyl.

24 Average of Bandow and Washida (1985b) and Atkinson and Aschmann (1994). The slightly 

lower yield of Tuazon et al (1986) not used but may not be outside of range of uncertainty.

25 Sum of yields of 2,4-, 2,5-, and 3,4-dimethylbenzaldehyde from Smith et al (1999)

26 Sum of 2,4,5-, 2,3,5-, and 2,3,6-trimethylphenol from Smith et al (1999)

27 Average of glyoxal yields of Bandow and Washida (1985b) and Smith et al (1999) and 3-methyl3-hexene-2,5-dione of Smith et al (1999). The lower value of Tuazon et al (1986) is not used. 

Yields of glyoxal and 3-methyl-3-hexene-2,5-dione are assumed to be equal.

28 Average of Bandow and Washida (1985b) and Smith et al (1999). The value of Tuazon et al 

(1986) is not used because of the higher NOx levels and for consistency with other assignments.

29 Average of Bandow and Washida (1985b) and Atkinson and Aschmann (1994). The lower yield 

of Tuazon et al (1986) is not used but may not be outside of range of uncertainty.

30 The 3,5-dimethylbenzaldehyde yield from Smith et al (1999) is used.

31 The 2,4,6-trimethylphenol yield from Smith et al (1999) is used.

34 The yield from Bandow and Washida (1985b) is used. The data of Smith et al (1999) appear to be 

high and the data from Tuazon et al (1986) was not used for consistency with assignments for the 

other trimethylbenzenes.

[b] Nitrate yield for each peroxy reaction. Total nitrate yield is less because not all pathways involve 

peroxy reactions.
36

BzCH3 + OH  H2O + BzCH2·

BzCH2· + O2  BzCH2OO·

BzCH2OO· + NO  NO2 + BzCH2O· (Fraction = n7)

  BzCH2ONO2 (Fraction = 1-n7)

BzCH2O· + O2  BzCHO + HO2

or ethylbenzene

BzCH2CH3 + OH  H2O + BzCH(·)CH3

BzCH(·)CH3 + O2  BzCH(OO·)CH3

BzCH(OO·)CH3 + NO  NO2 + BzCH(O·)CH3 (Fraction = n8)

  BzCH(ONO2)CH3 (Fraction = 1-n8)

BzCH(O·)CH3 + O2  BzC(O)CH3 + HO2

Here, "Bz" refers to the aromatic ring, and n7 and n8 refer to the nitrate yields assumed for aromatics with 

7 or 8 carbons, which are derived as discussed below. In terms of SAPRC-07 model species, these overall 

processes are represented as

TOLUENE + OH  (1-n7) {RO2C + xBALD} + (n7) zRNO3 + yR6OOH

C2-BENZ + OH  (1-n8) {RO2C + PROD2} + (n8) Zrno3 + yR6OOH

In general, the model species "BALD" is used to represent aromatic aldehydes such as benzaldehyde and 

tolualdehyde, PROD2 is used to represent aromatic ketones such as methyl phenyl ketone and methyl 

benzyl ketone, RNO3 is used to represent the organic nitrates formed from peroxy + NO reactions in the 

aromatic and other systems, and R6OOH is used to represent the hydroperoxides formed in the reactions 

off the aromatic ring. 

Reactions on the Aromatic Ring. The major uncertainty concerning the reactions of 

aromatics with OH radicals concern the subsequent reactions after OH adds to the aromatic ring. 

Information and data concerning what is known about these processes is discussed by Calvert et al 

(2002), and that discussion is not duplicated here. The general model we assume for these reactions, 

which is probably an oversimplification of what really happens, is shown on Figure 2, using benzene as 

an example. The processes are assumed to be analogous for the substituted benzenes such as toluene, 

xylenes, etc., except that the number of reactions and products are much greater because of various 

possible positions of the substituents on the intermediates and the products.

The products that are known to be formed and whose yields have been quantified include 

the phenols and cresols, and the -dicarbonyls (phenol and glyoxal in the case or benzene). The formation 

of phenols is generally assumed to occur by OH abstraction of the initial OH - aromatic adduct, as shown 

on Figure 2 as "A". The observed yields of these phenolic products are then used to derive the branching 

ratio (a)/(1-a) as shown on the figure. The co-product is HO2, formed without the intermediacy of any

peroxy radicals and without any NO to NO2 conversions.

The processes forming the -dicarbonyls are more uncertain, but the most chemically 

reasonably process involves O2 addition to form a peroxy radical that then internally adds to the double 

bonds to form an allylic-stabilized bicyclic radical, which subsequently reacts to form the -dicarbonyl(s) 

as shown on Figure 2 as the processes leading to product set "B". The predicted co-products are the 

monounsaturated 1,4-dicarbonyls, such as the 2-butene 1,4-dial predicted for the benzene system. These 

products are indeed observed (Calvert et al, 2002, and references therein), though the total yields are 

generally much less than the total -dicarbonyl yields. This could be due to other, unknown, processes 

leading to the -dicarbonyls, or with problems with quantifying the unsaturated 1,4-dicarbonyls, which 

are highly reactive. In any case, because of lack of available information and chemically reasonable 
37

HC

HC

C

H

CH

C

C H

H

O

O

O

HC

HC

C

H

CH

HC

CH

O

O

OH HC 

HC

C

H

CH

C

C H

H

OH

O

O

 

HC

HC

C

H

CH

CH

 

C

H

OH

HC

HC

C

H

CH

 

CH

CH

OH

O

O

HC

HC

C

H

HC

CH

CH

OH

O

O

O

O

 

HC

HC

C

H

HC

CH

CH

OH

O

O

O

 

CH

HC

C

H

C

H

O

O

HC

CH

HO 

O

C

H

C

H

C

H

C

O H

O

HC

CH

O

O

OH

HC

HC

C

H

HC

CH

CH

OH

O

O

O N

O

O

HC

HC

C

H

HC

CH

CH

OH

O

O

O OH

HC

HC

C

H

CH

C

C H

H

OH

O

 

+

H

O2

+

O2 NO

NO2

+ + HO2

O2

O2

+ HO2

(1-a)

(a)

(1-b)

(b)

NO (n6)

(1-n6)

HO2

O2

A

D C B

E

(obs)

(obs)

NO NO2

Other Products

(x)

Figure 2. Reactions of the OH - aromatic ring adduct that are assumed in the current mechanism. 

The example shown is for benzene, but analogous reactions are assumed for the 

alkylbenzenes.

alternatives to explain the products that are observed, we assume that the processes leading to "B" as 

indicated on Figure 2 are the only processes in the forming the -dicarbonyls in the primary OH + 

aromatic reactions, and that the unsaturated 1,4-dicarbonyls are the corresponding co-products. The yields 

of the model species used to represent the unsaturated 1,4-dicarbonyls (discussed below) are then set as 

the total yields of the measured -dicarbonyl products. The total -dicarbonyl and phenolic product 

yields are used to determine the branching ratio indicated as (b)/(1-b) on Figure 2.

Note that this process that are assumed to account for the -dicarbonyl formation involve 

the intermediacy of a peroxy radical that converts NO to NO2 in the processes of forming these products, 

but that can also react with NO to form an alkyl nitrate ("C" on Figure 2), react with HO2 to form a highly 

oxygenated bicyclic hydroperoxide ("D" on Figure 2), or react with other peroxy radicals to form other 

products (not shown on the figure). The hydroperoxides formed in the HO2 reaction (e.g., "D") are 

represented by a separate model species RAOOH because they are expected to have higher PM formation 

potential than other hydroperoxides, though they could be lumped with R6OOH if SOA predictions are 

not important. The general procedures used for representing products formed from peroxy reactions in 

this mechanism have been discussed previously, and these procedures are employed for these -

dicarbonyl and mono-unsaturated 1,4-dicarbonyl products.
38

The sum of the measured yields of the phenolic and -dicarbonyl products from the OH 

addition reactions, the aromatic aldehydes from the abstraction reactions off the aromatic ring, and 

estimated nitrate yields from the peroxy + NO reactions (discussed below) is not sufficient to account for 

all the processes involved in the OH reactions of toluene, xylene, and trimethylbenzenes (Calvert et al, 

2002), so additional processes must also occur. The results of aromatic - NOx environmental chamber 

experiments at various NOx levels cannot be simulated by mechanisms that assume that yields of the 

photoreactive aromatic products such as -dicarbonyls or the monounsaturated 1,4-dicarbonyls are 

affected by total NOx levels, and most of the available product data for the -dicarbonyls from 

methylbenzenes do not indicate a NOx -dependence on -dicarbonyl yields at the NOx levels relevant to 

the atmosphere and the chamber experiments used for mechanism evaluation. This rules out mechanisms 

involving competitions between unimolecular reactions of peroxy radicals and reactions of peroxy 

radicals with NO, such as between (b) and (x) shown on Figure 2. 

An additional consideration concerning potential competing processes is the fact that the 

direct reactivity experiments of Carter and Malkina (2002) indicate that the SAPRC-99 mechanism has 

too many NO to NO2 conversions in the reactions of aromatics with OH. We were unable to come up with 

chemically reasonable mechanisms for -dicarbonyl, phenol or cresol, or aromatic aldehyde formation 

that involved fewer NO to NO2 conversions, which leaves only the remaining process(es) forming the 

remaining products. Because of this, and also to avoid introducing competitions between unimolecular 

and peroxy + NO reactions, we assume that the additional process involves a 6-member ring H-shift of 

the aromatic - OH - O2 adduct, giving rise to formation of a di-unsaturated 1,6-dicarbonyl and OH 

radicals, shown as process (1-b) and "E" on Figure 2. This is a competition between two unimolecular 

reactions and thus the photoreactive product yields are predicted to be independent of NOx, and the direct 

formation of OH radicals in this set of reactions involves two fewer NO to NO2 conversions than assumed 

for these unknown processes in the SAPRC-99 mechanism. Therefore, this is used in the current 

mechanism to represent all the processes that are not otherwise accounted for by the observed formation 

of aromatic aldehyde, phenolic, and -dicarbonyl products and the estimated formation of organic 

nitrates. The model species used to represent these di-unsaturated 1,6-dicarbonyls is discussed below. 

Estimation of Nitrate Formation Reactions. The mechanisms involving OH abstractions 

off the aromatic ring, and also the mechanism involving the formation of the -dicarbonyls and the 

monounsaturated 1,4-dicarbonyls all involve the intermediacy of peroxy radicals that can react with NO 

to form the corresponding nitrate. The only data available concerning nitrate formation from peroxy + NO 

reactions in alkylbenzene systems concerns the observed formation of benzyl nitrate in the toluene 

system, for which the average of the yields tabulated by Calvert et al (2002) is ~0.8%. This is attributed to 

the reaction of benzyl peroxy radicals with NO (shown above), for which the competing process is 

formation of the alkoxy radical that reacts with O2 to form benzaldehyde. Based on this and the 

benzaldehyde yield used in our toluene mechanism (discussed below), we derive an overall nitrate yield 

for the benzyl peroxy radical to be 10.6%. This can be compared with the 13.5% nitrate yield predicted by 

the mechanism generation system for 7 carbons for standard secondary alkylperoxy radicals formed in the 

alkane photooxidation system (Carter, 2000a). Based on this, we assume that nitrate yields for all peroxy 

radicals in aromatic systems, whether resulting from abstractions by OH off the ring or formation of -

dicarbonyls following OH + aromatic ring additions, are 78.5% those estimated for secondary alkyl 

peroxy radicals. Figure 3 shows the dependence of the nitrate yields on carbon number that is used when 

deriving aromatic mechanisms for SAPRC-07. The nitrate yields are assumed to range from ~8% for 

benzene (n6) to ~21% for aromatics with carbon numbers greater than ~13 (n13+).

Assignments of Branching Ratios and Product Yields. Table 9 gives the measured or 

estimated yields from the known products from benzene, toluene, the xylenes, and the trimethylbenzenes 

that are used as the basis for the aromatic mechanisms derived for this work. Footnotes to the table 
39

Figure 3. Nitrate yield factors used for estimating aromatic oxidation mechanisms

indicate the basis for the assignments or estimates used. These were used, in conjunction with the nitrate 

yield estimates derived above, as the basis for deriving the branching ratios for all the reactions in the 

mechanisms for these aromatics. Note that, as discussed above, the total yields of the model species used 

for the mono-unsaturated 1,4-dicarbonyls were set to the sum of the glyoxal, methyl glyoxal, and biacetyl 

yields shown on Table 9, and the yields of the model species representing the di-unsaturated 1,6-

dicarbonyls was set at 1 - the sum of the aromatic aldehyde, phenol or cresol, -dicarbonyl, and estimated 

nitrate yields.

For the other alkylbenzenes or model species used to represent groups of alkylbenzenes 

with similar structures and carbon numbers, the mechanisms were derived based on estimates for 

reactions at various positions on the molecule and other estimates, as follows. The total rate constants for 

abstraction reactions off the aromatic ring were derived using structure-reactivity estimates, using the OH 

abstraction rate parameters given on Table 3, above. These total non-ring rate constants are given for the 

various aromatic model species on Table 10, along with the substituents assumed for the various model 

species used to represent groups of compounds. The total rates for additions to the aromatic ring were 

estimated by assuming they were the same as to those derived for the methylbenzene with the most 

similar structure, as indicated on Table 10. The ring addition reactions for those compounds were derived 

from the total rate constant and the estimated extent of abstraction off the aromatic ring derived from the 

aromatic aldehyde and estimated off-ring abstraction rate constant derived from the aromatic aldehyde 

and estimated nitrate yield as indicated on Table 9. The fractions of ring additions vs. off-ring abstractions 

were derived from the ratio of the estimated rate constants for the two processes, and are shown on Table 

10. Note that for the compounds listed on Table 9 the mechanisms used the values derived based on the 

measured or estimated product yields shown on that table, not based on the estimated rate constants 

shown on Table 10. Table 10 shows the differences between the off-ring abstraction fractions derived 

using these two methods for these compounds. 

0%

5%

10%

15%

20%

25%

30%

6 7 8 9 10 11 12 13 14 15 16

Carbon number

Nitrate yield in Peroxy + N

O reaction

Nitrate yield factor used for secondary alkyl radical estimates

Derived from Benzyl Nitrate / Benzaldehyde yield ratios from toluene

Nitrate yield factors used for aromatics mechanism estimates
40

Table 10. Rate constants and assumptions used to estimate fractions of reaction of on and off the aromatic ring for the reactions of OH with 

aromatic compounds or groups of compounds for which mechanistic parameters have been derived.

Compound or detailed model 

species group

Rate Constant [a] Ring k 

Based on

Non-Ring Rxn. Substituents [c] Total Non-Ring Ring Expt [b] Est'd

Toluene 5.58e-12 4.92e-13 5.18e-12 Toluene 7% 9% methyl

o-Xylene 1.36e-11 9.85e-13 1.29e-11 o-Xyl. 5% 7% dimethyl

m-Xylene 2.31e-11 9.85e-13 2.20e-11 m-Xyl. 5% 4% dimethyl

p-Xylene 1.43e-11 9.85e-13 1.28e-11 p-Xyl. 10% 7% dimethyl

1,2,3-Trimethyl benzene 3.27e-11 1.48e-12 3.11e-11 124-TMB 5% trimethyl

1,2,4-Trimethyl benzene 3.25e-11 1.48e-12 3.11e-11 124-TMB 4% 5% trimethyl

1,3,5-Trimethyl benzene 5.67e-11 1.48e-12 5.47e-11 135-TMB 4% 3% trimethyl

Ethylbenzene 7.00e-12 2.05e-12 5.18e-12 Toluene 28% ethyl

n-Propyl benzene 5.80e-12 3.64e-12 5.18e-12 Toluene 41% 1-propyl

o-Ethyl toluene 1.19e-11 2.54e-12 1.29e-11 o-Xyl. 16% methyl ethyl

m-Ethyl toluene 1.86e-11 2.54e-12 2.20e-11 m-Xyl. 10% methyl ethyl

p-Ethyl toluene 1.18e-11 2.54e-12 1.28e-11 p-Xyl. 17% methyl ethyl

Isopropyl benzene 6.30e-12 1.68e-12 5.18e-12 Toluene 24% 2-propyl

1-Methyl-4-isopropylbenzene 1.45e-11 2.17e-12 1.28e-11 p-Xyl. 14% methyl 2-propyl

t-Butyl benzene 4.50e-12 5.13e-13 5.18e-12 Toluene 9% t-butyl

C10 monosubstituted benzenes 9.58e-12 4.40e-12 5.18e-12 Toluene 46% 0.33 n-butyl + 0.33 2-methyl-1-propyl + 0.34 1-methyl-1-propyl

C11 monosubstituted benzenes 1.10e-11 5.82e-12 5.18e-12 Toluene 53% 0.33 n-pentyl + 0.33 3-methyl-1-butyl + 0.34 1-methyl-1-butyl

C12 monosubstituted benzenes 1.24e-11 7.25e-12 5.18e-12 Toluene 58%

As above, but with -CH2- added

C13 monosubstituted benzenes 1.38e-11 8.67e-12 5.18e-12 Toluene 63%

C14 monosubstituted benzenes 1.53e-11 1.01e-11 5.18e-12 Toluene 66%

C15 monosubstituted benzenes 1.67e-11 1.15e-11 5.18e-12 Toluene 69%

C16 monosubstituted benzenes 1.81e-11 1.29e-11 5.18e-12 Toluene 71%

o-C10 disubstituted benzenes 1.64e-11

3.51e-12

1.29e-11 o-Xyl. 21%

m-C10 disubstituted benzenes 2.55e-11 2.20e-11 m-Xyl. 14% 0.25 methyl n-propyl + 0.25 methyl isopropyl + 0.5 diethyl

p-C10 disubstituted benzenes 1.64e-11 1.28e-11 p-Xyl. 21%

o-C11 disubstituted benzenes 1.82e-11

5.40e-12

1.29e-11 o-Xyl. 30% 0.34 methyl (2-metyl-1-propyl) + 0.33 ethyl isopropyl + 0.33 

ethyl n-propyl m-C11 disubstituted benzenes 2.74e-11 2.20e-11 m-Xyl. 20%

p-C11 disubstituted benzenes 1.82e-11 1.28e-11 p-Xyl. 30%

o-C12 disubstituted benzenes 1.90e-11

6.14e-12

1.29e-11 o-Xyl. 32% 0.25 methyl (3-methyl-1-butyl) + 0.25 ethyl (1-methyl-1-propyl) 

+ 0.25 propyl isopropyl + 0.25 ethyl n-butyl m-C12 disubstituted benzenes 2.82e-11 2.20e-11 m-Xyl. 22%

p-C12 disubstituted benzenes 1.90e-11 1.28e-11 p-Xyl. 32%

o-C13 disubstituted benzenes 2.05e-11

7.63e-12

1.29e-11 o-Xyl. 37% 0.25 ethyl (3-methyl-1-butyl) + 0.25 propyl (1-methyl-1-propyl) 

+ 0.25 (2-methyl-1-propyl) isopropyl + 0.25 ethyl n-pentyl m-C13 disubstituted benzenes 2.96e-11 2.20e-11 m-Xyl. 26%

p-C13 disubstituted benzenes 2.05e-11 1.28e-11 p-Xyl. 37%
Table 10 (continued)

41

Compound or detailed model 

species group

Rate Constant [a] Ring k 

Based on

Non-Ring Rxn. Substituents [c] Total Non-Ring Ring Expt [b] Est'd

o-C14 disubstituted benzenes 2.19e-11

9.05e-12

1.29e-11 o-Xyl. 41%

As above, but with -CH2- added

m-C14 disubstituted benzenes 3.11e-11 2.20e-11 m-Xyl. 29%

p-C14 disubstituted benzenes 2.19e-11 1.28e-11 p-Xyl. 41%

o-C15 disubstituted benzenes 2.33e-11

1.05e-11

1.29e-11 o-Xyl. 45%

m-C15 disubstituted benzenes 3.25e-11 2.20e-11 m-Xyl. 32%

p-C15 disubstituted benzenes 2.33e-11 1.28e-11 p-Xyl. 45%

o-C16 disubstituted benzenes 2.48e-11

1.19e-11

1.29e-11 o-Xyl. 48%

m-C16 disubstituted benzenes 3.39e-11 2.20e-11 m-Xyl. 35%

p-C16 disubstituted benzenes 2.47e-11 1.28e-11 p-Xyl. 48%

1,2,3-C10 trisubstituted benzenes 3.41e-11

3.03e-12

3.11e-11 124-TMB 9%

1,2,4-C10 trisubstituted benzenes 3.41e-11 3.11e-11 124-TMB 9% Dimethyl ethyl

1,3,5-C10 trisubstituted benzenes 5.77e-11 5.47e-11 135-TMB 5%

1,2,3-C11 trisubstituted benzenes 3.57e-11

4.60e-12

3.11e-11 124-TMB 13%

1,2,4-C11 trisubstituted benzenes 3.57e-11 3.11e-11 124-TMB 13% 0.5 dimethyl propyl + 0.5 methyl diethyl

1,3,5-C11 trisubstituted benzenes 5.93e-11 5.47e-11 135-TMB 8%

1,2,3-C12 trisubstituted benzenes 3.66e-11

5.47e-12

3.11e-11 124-TMB 15% 0.34 dimethyl 2-methyl-1-propyl + 0.33 methyl ethyl isopropyl 

+ 0.33 methyl ethyl n-propyl 1,2,4-C12 trisubstituted benzenes 3.66e-11 3.11e-11 124-TMB 15%

1,3,5-C12 trisubstituted benzenes 6.01e-11 5.47e-11 135-TMB 9%

1,2,3-C13 trisubstituted benzenes 3.81e-11

7.00e-12

3.11e-11 124-TMB 18% 0.34 methyl ethyl 2-methyl-1-propyl + 0.33 methyl ethyl n-butyl 

+ 0.33 methyl propyl isobutyl 1,2,4-C13 trisubstituted benzenes 3.81e-11 3.11e-11 124-TMB 18%

1,3,5-C13 trisubstituted benzenes 6.17e-11 5.47e-11 135-TMB 11%

1,2,3-C14 trisubstituted benzenes 3.93e-11

8.16e-12

3.11e-11 124-TMB 21% 0.25 methyl ethyl 3-methyl-1-butyl + 0.25 methyl n-propyl nbutyl + 0.25 ethyl isopropyl n-propyl 1,2,4-C14 trisubstituted benzenes 3.93e-11 3.11e-11 124-TMB 21%

1,3,5-C14 trisubstituted benzenes 6.28e-11 5.47e-11 135-TMB 13%

1,2,3-C15 trisubstituted benzenes 4.04e-11

9.31e-12

3.11e-11 124-TMB 23% 0.25 methyl ethyl 4-methyl-1-pentyl + 0.25 ethyl n-propyl 1-

methyl-1-propyl + methyl propyl 1-methyl-1-butyl + ethyl 

isopropyl 2-methyl-1-propyl

1,2,4-C15 trisubstituted benzenes 4.04e-11 3.11e-11 124-TMB 23%

1,3,5-C15 trisubstituted benzenes 6.40e-11 5.47e-11 135-TMB 15%

1,2,3-C16 trisubstituted benzenes 4.17e-11

1.06e-11

3.11e-11 124-TMB 25% 0.25 ethyl propyl 3-methyl-1-butyl + 0.25 ethyl propyl 1-methyl1-butyl + methyl propyl 1,3-dimethyl-1-butyl + 0.25 propyl 

isopropyl 2-methyl-1-propyl

1,2,4-C16 trisubstituted benzenes 4.17e-11 3.11e-11 124-TMB 25%

1,3,5-C16 trisubstituted benzenes 6.52e-11 5.47e-11 135-TMB 16%

[a] Rate constant in cm3 molec-1s

-1

. "Total" is total rate constant is rate constant used in the mechanism, either experimental or estimated. "Non-Ring" is total 

rate constant for abstraction at various positions off the aromatic ring, estimated using the group additivity factors shown in Table 4. "Ring" is estimated rate 

constant for addition to the aromatic ring, derived by assuming the same aromatic ring addition rate constant as the indicated compound.

[b] Derived from the measured yields of the expected non-ring abstraction product, corrected for estimated nitrate formation, relative to the total rate constant. 

These can be compared with the estimated ratios of non-ring reaction, derived from the estimated ring and non-ring rate constants.

[c] Substituents assumed when estimating rate constants for abstraction reactions off the aromatic ring.
42

The products formed from the off-ring abstraction reactions are represented by the 

organic nitrate model species RNO3 and either the aromatic aldehyde model species BALD or the 

reactive ketone model species PROD2, depending on the substituent. The RNO3 yield was derived from 

the carbon number as discussed above. If the substituent is a methyl group the reaction was expected to 

form an aromatic aldehyde and the product was represented by the benzaldehyde model species BALD. 

Otherwise, the products are assumed to be primarily ketones and are represented by PROD2.

The products used to represent those formed from the reactions following the addition to 

the aromatic ring were derived based on those derived for the corresponding reactions of ethylbenzene, a 

xylene, or a trimethylbenzene, depending on the structure of the compound or group of compounds being

represented. The ring-reaction products for ethylbenzene were used for the ring reactions products for the 

monoalkylbenzenes, the ring-reaction products for o-xylene were used for all 1,2-disubstituted benzenes, 

those for 1,2,3-trimethylbenzene were used for all the 1,2,3-trisubstituted benzenes, and similarly for the 

other isomers. The ring-reaction products for ethylbenzene were derived from those derived for toluene, 

taking into account estimated differences in off-ring reactions and nitrate yields, and with the ratio of the 

photoreactive and non-photoreactive model species used for the mono-unsaturated 1,4-dicarbonyls 

adjusted to fit the chamber data for ethylbenzene (see discussion of these products, below). The ring 

reaction products for the xylene and trimethylbenzene isomers were derived from the product data for 

those compounds as shown on Table 9, ratio of the photoreactive and non-photoreactive model species 

used for the monounsaturated 1,4-dicarbonyls adjusted to fit the chamber data for those compounds. 

These are summarized on Table 11.

The mechanistic assignments shown on Table 9, Table 10, Table 11 and Figure 3 were 

used to derive overall mechanisms for the individual aromatics or groups or aromatics as listed on Table 

10. The resulting overall rate constants are given on Table B-4 and the mechanisms are given in Table B2 in Appendix B. Footnotes to Table B-4 indicate the sources of the rate constants that were used.

Representation of Unsaturated Dicarbonyl Products

As discussed above, the co-products assumed to be formed with the -dicarbonyls in the 

ring opening products are the monounsaturated 1,4-dicarbonyls, and the ring opening reactions not 

involving these products are assumed to be di-unsaturated 1,6-dicarbonyls. For the benzene system, these 

consist of 2-butene-1,4-dial and 2,4-hexadienedial as shown on Figure 2, while for the methylbenzenes 

various methyl substituted isomers can be formed, with relative yields depending on the position of OH 

addition to the double bond, and also where the O2 adds to the OH - aromatic adduct. Estimated 

distributions of these products for the various methylbenzene isomers are shown on Table 12. These 

estimates were derived based on estimated fractions of reaction of OH radicals at various positions of the 

molecules and estimated branching ratios for O2 addition at the various positions of the OH + aromatic 

adducts, adjusted to be consistent with the observed yields of the -dicarbonyl co-products1.

This product distribution can serve as the basis for deriving explicit or semi-explicit 

mechanisms for the OH reactions of these aromatics. However, for airshed and reactivity simulations a 

more generalized mechanism, with a more limited number of model species, is needed. The model species 

used to represent these products in this version of the mechanism is indicated on Table 12. The reasoning 

behind this representation, and the derivations of their mechanisms, are discussed below. Note that this is 

the same number of model species used to represent uncharacterized ring fragmentation products in 

SAPRC-99, but in this case the mechanisms are derived based on estimations for actual compounds.

 

1 These estimates were made as part of the initial effort to derive explicit aromatics mechanisms, which is 

beyond the scope of the present report.
43

Table 11. Model species used to represent non-nitrate products from the reactions of OH radicals at 

aromatic rings for various types of ring structures. Yields are normalized to OH ring 

addition only, excluding nitrate formation.

Ring structure

A [a] B [b] B, C, D E

CRES + 

HO2 xGLY xMGLY xBACL xAFG1+2 [c]

AFG1/2 

[d]

xAFG3

[e]

Peroxy 

Total [f]

AFG3 + 

OH [e]

Benzene 12% 31% 31% 0.11 31% 31%

Toluene 34% 29% 18% 47% 1.00 29% 29%

Ethylbenzene [g] (based on toluene) 0.39 (same as toluene)

o-Xylene 21% 10% 29% 23% 62% 1.00 10% 10%

m-Xylene 25% 12% 46% 58% 2.33 12% 12%

p-Xylene 31% 37% 14% 14% 0.67 37% 37% 37%

1,2,3-Trimethylbenzene 9% 9% 23% 56% 88% 1.00 9% 9%

1,2,4-Trimethylbenzene 24% 9% 50% 14% 55% 0.25 19% 9% 9%

1,3,5-Trimethylbenzene 17% 79% 79% 1.00

[a] Pathway on Figure 2 that these model species are being used to represent.

[b] Yields depend on nitrate yield in peroxy + NO reactions, and are shown for nitrate yields of zero. Actual yields 

are (tabulated yields) x (1-nx), where "nx" refers to the nitrate yield for carbon number "x", determined as 

shown on Figure 3. The prefix "x" is used to indicate that they are formed following reactions of peroxy radicals 

with NO (see discussion of the base mechanism).

[c] This is the total yield of monounsaturated 1,4 dialdehydes or aldehyde-ketones, represented by xAFG1 + 

xAFG2.

[d] This is the ratio of the xAFG1 to xAFG2 yield, which is adjusted to aromatic - NOx chamber data for the 

indicated compound

[e] AFG3 is the model species used to represent both monounsaturated 1,4-diketones and di-unsaturated 1,6-

dicarbonyls.

[f] This is the total level of peroxy radicals in the reaction, and also the total NO to NO2 conversion + nitrate 

formation. The yield of RO2C, representing NO to NO2 conversion, is given by the tabulated value x (1-nx), 

and the nitrate yield, represented by RO2XC + zRNO3, is given by the tabulated value x (nx), where "nx" is the 

nitrate yield factor as indicated in Footnote [b]. The tabulated values also give the yields of yRAOOH, which is 

used to represent the 

[g] The yields are based on those derived for toluene, but are slightly different because of differences between the 

estimated and total rate constants. However, the AFG1/AFG2 yields (AFG1/2) were adjusted separately to fit 

the chamber experiments for ethylbenzene.

Available data and theories concerning the atmospheric reactions of these unsaturated 

dicarbonyl ring-opening products are discussed by Calvert et al (2002). These compounds react at 

significant rates with OH radicals and O3 and information is available concerning the rate constants for 

representative compounds. These compounds can also photolyze at significant rates under atmospheric 

conditions, and absorption cross-section data are also available for representative compounds. The 

quantum yields are more uncertain but measurements of photolysis consumption rates have been made in 

the Euphore outdoor chamber that can serve as a basis for estimating overall quantum yields for 

consumption by photolysis. The extent to which these photolysis reactions form radicals is a very 

important factor affecting the contribution of these products to the overall reactivity of the aromatic 

starting material. The limited product and environmental chamber reactivity data indicate that photolysis 

to form radicals is important for the mono-unsaturated 1,4-dialdehydes and aldehyde-ketones, but that the 

photolysis of the mono-unsaturated 1,4-diketones and the di-unsaturated 1,6-dicarbonyls is much less 
44

Table 12. Estimated yields for unsaturated dicarbonyl products in the OH reactions of the 

methylbenzenes for which -dicarbonyl yield data are available.

Ring fragmentation product 

compound or type of compound

Methylbenzene Reactant

Toluene Xylenes Trimethylbenzenes

o- m- p- 1,2,3- 1,2,4- 1,3,5-

Aldehydes and aldehyde-ketones (Represented by AFG1 and AFG2)

2-Butene-1,4-dial 0.15 0.19

2-Methyl-2-butene-1,4-dial 0.12 0.19 0.11 0.11

2,3-Dimethyl-2-butene-1,4-dial 0.03 0.12

4-Oxo-2-penteneal 0.11 0.24 0.19 0.45

2-Methyl-4-oxo-2-penteneal 0.10 0.10 0.64

3-Methyl-4-oxo-2-penteneal 0.05 0.18 0.11

2,3-Dimethyl-4-oxo-2-penteneal 0.07

Diketones (Represented by AFG3)

3-Methyl-3-hexene-2,5-dione 0.29 0.08

Diunsaturated dicarbonyls (Represented by AFG3)

Methyl-substituted 1,4-

hexadienedials 0.22 0.09 0.09 0.12 0.03 0.05

6-Oxo-2,4-hepadienedial and 

methyl substituted isomers 0.09 0.08 0.15 0.15 0.03 0.15 0.16

3,5-Octadiene-2,7-dione and 

methyl substituted isomers 0.03 0.03 0.03

efficient, or forms primarily non-radical products. Calvert et al (2002), and references therein, should be 

consulted for details.

Based on this information, we use two model species, designated AFG1 and AFG2, to 

represent the highly photoreactive mono-unsaturated dialdehydes and aldehyde-ketones, and a separate 

model species, AFG3, to represent the less photoreactive unsaturated diketones and di-unsaturated 

dicarbonyls. Because the overall quantum yields for photolyses of the mono-unsaturated dialdehydes and 

aldehyde-ketones to form radicals are very important in affecting overall reactivity but are uncertain and 

may vary from compound to compound, these are treated as adjustable parameters in the mechanism. This 

is implemented by using two model species for these compounds that have exactly the same mechanisms, 

except that one (AFG1) photolyzes to form radicals, while the other (AFG2) photolyzes at the same rate 

but forms non-radical products. The total yields of these model species are set at the total estimated 

monounsaturated aldehyde yield as indicated on Table 12, while the yield of one relative to the other are 

adjusted to predict overall reactivities that are consistent with results of environmental chamber 

experiments with the various aromatics. This is equivalent to adjusting separately the overall quantum 

yields for formation of radical vs. non-radical products for photoreactive dicarbonyls for each compound 

without having to use a separate model species for each compound.

As indicated in footnotes to Table A-2 in Appendix A, the mechanisms for AFG1 and 

AFG2 was derived based on those estimated for the representative dialdehydes and diketones 2-butene 

1,4-dial 2-methyl-2-butene-1,4-dial, 4-oxo-2-petenal, and 2-methyl-4-oxo-2-pentenal, and the mechanism 

for AFG3 was derived based on those estimated for the represented di-unsaturated dicarbonyl products 3-

methyl 2,4-hexene-1,6-dial, 6-oxo-2,4-heptadienal, and 3,5-octadien-2,7-dione. The relative contributions 

of each are based on relative yields of these and similar products from the methylbenzenes, as indicated 

on Table 12. Use of a separate model species, based on mechanisms for 3-methyl-3-hexene-2,5-dione, to 

represent the mono-unsaturated diketones was examined in an initial version of this mechanism. 

However, but it was found that lumping it with the model species used for the di-unsaturated dicarbonyls 
45

gave essentially the same reactivity predictions for p-xylene and 1,2,4-trimethylbenzene, the only 

compounds for which reactivity data are available where these products are predicted to be formed. 

Therefore, it was determined that use of a separate model species to represent these mono-unsaturated 

diketones was not necessary.

The mechanisms for the reactions of these model species with OH and O3 were derived 

using the enhanced mechanism generation system, using assignments for the specific compounds that are 

given on Table 13. The reactions of these species with NO3 and O

3

P were assumed to be negligible 

compared to the other processes and are not included in the mechanism. The mechanism for the 

photolysis of AFG1 to form radicals is based on the assignments for the initial reactions that are also 

given on Table 13. Specific mechanisms were not generated for the photolyses of AFG2 to form stable 

products; the unspecified products formed are assumed to be moderately reactive and are represented by 

the model species PROD2. The overall mechanisms that were derived for these model species using this 

method are given with the listing of the base mechanism on Table A-2 in Appendix A.

The absorption cross sections and quantum yields for the photolyses of AFG1 and AFG2 

were derived from those for 2-butene-1,4-dial and 4-oxo-2-pentenal, assuming those for 2-methyl-2-

butene-1,4-dial and 2-methyl-4-oxo-2-pentenal are the same as those for 2-butene-1,4-dial and 4-oxo-2-

pentenal, respectively. The derivations of the absorption cross sections and quantum yields used are 

indicated on Table 13, and plots of the action spectra (absorption cross sections x overall quantum yields) 

for these two compounds are shown on Figure 4, where they are compared with that derived for AFG1 

and AFG2, which is the weighed average based on ratios of these compounds used to derive the rate 

constants and mechanisms for the other reactions (see footnotes to Table A-2 in Appendix A). The action 

spectrum for AFG1,2 most closely resembles that for 4-oxo-2-pentenal because of the higher absorption 

cross sections and quantum yields and also because of the higher weighting of the aldehyde-ketone 

products (68%) compared to the dialdehyde products (32%).

Note that although this representation uses the same number of model species as SAPRC99 to represent the unspecified non--dicarbonyl aromatic ring opening products, the meaning and the 

mechanisms of these species is different. In SAPRC-99 the model species DCB1 is used to represent nonphotoreactive product species, DCB2 represents photoreactive products with action spectra like -

dicarbonyls, and DCB3 represents photoreactive products with action spectra like acrolein. The yields of 

DCB1 for various aromatics were set more or less arbitrarily, while those for DCB2 and DCB3 were 

adjusted to fit the aromatics - NOx chamber data, with species with the different action spectra being 

needed to simulate experiments using differing light sources. In this mechanism, the total yields are set 

based on other product data or estimates that are independent of the chamber data, and only the 

AFG1/AFG2 yield ratio is adjusted to fit the chamber data. Note that the action spectra are derived 

independently of the chamber data, with no adjustments to account for reactivity differences using 

chambers with different light sources. This resulted in some cases in the SAPRC-07 mechanism not 

performing as well as SAPRC-99 in simulating blacklight chamber data, but in general model 

performance was satisfactory, indicating that the un-adjustable action spectra used in the model may be 

appropriate. This is discussed further in the "Mechanism Evaluation Results" section, below.
46

Table 13. Mechanism estimation assignments made for representative unsaturated dicarbonyl 

compounds for the purpose of generating mechanisms for the aromatic fragmentation 

product model species AFG1-3.

Compound, reaction, and rate parameters Fraction

2-Butene-1,4-dial

OH Rate Constant = 5.29e-11 cm3 molec-1s

-1

HCOCH=CHCHO + OH  HCOCH(·)CH(CHO)OH 44%

HCOCH=CHCHO + OH  H2O + HCOCH=CHC(O)· 56%

Rate constant from Bierbach et al (1994). Branching ratios estimated by assuming that 

abstraction from CHO has a rate constant per CHO group as estimated acrolein.

O3 Rate Constant = 1.60e-18 cm3 molec-1s

-1

HCOCH=CHCHO + O3  HCOCHOO[excited] + HCOCHO

Rate constant from Liu et al (1999).

h Photolysis Set = BUTEDIAL, Quantum Yield = 0.723

HCOCH=CHCHO + h  HCOCH=CHC(O)· + H. 50%

HCOCH=CHCHO + h  HCO· + HCOCH=CH. 50%

The absorption coefficients are from Liu et al (1999) (file provided by Ken Sexton, 

University of North Carolina), normalized as discussed by Calvert et al (2002). The 

quantum yield is set to give the photolysis rate, relative to NO2, of 0.18, based on data 

of Sorensen and Barnes (1998). Only the radical formation pathways (used for AFG1) 

are shown on this table -- stable compounds formed by AFG2 are represented by 

PROD2 regardless of the compounds used to derive the mechanisms. The radicalproducing processes are uncertain, and the two shown are assumed to be most likely 

and to be equally important.

2-Methyl-2-butene-1,4-dial

OH Rate Constant = 9.63e-11 cm3 molec-1s

-1

CH3C(CHO)=CHCHO + OH  CH3C(·)(CHO)CH(CHO)OH 52%

CH3C(CHO)=CHCHO + OH  CH3C(CHO)(OH)CH(·)CHO 17%

CH3C(CHO)=CHCHO + OH  H2O + CH3C(CHO)=CHC(O)· 31%

The rate constant and branching ratios derived from estimated rate constants for 

reactions at various locations. Reaction by abstraction from CHO assumed to have 

same rate constant per CHO as assumed for acrolein. Addition to the double bond is 

calculated from OH addition rate constants for 1,4-butanedial x methacrolein / 

acrolein. The relative rates of addition at the various positions are assumed to be the 

same as used by the mechanism generation system for alkenes with 3 substituents 

about the double bond.

O3 Rate Constant = 6.66e-18 cm3 molec-1s

-1

CH3C(CHO)=CHCHO + O3  CH3COO[excited]CHO + HCOCHO 70%

CH3C(CHO)=CHCHO + O3  HCOCHOO[excited] + CH3C(O)CHO 30%

The rate constant is estimated from the O3 rate constants for 1,4-butanedial x 

methacrolein / acrolein. The branching ratios were derived by the mechanism 

generation system based on assignments for trisubstituted alkenes.

h Photolysis Set = BUTEDIAL, Quantum Yield = 0.723

CH3C(CHO)=CHCHO + h  H. + CH3C(CHO)=CHC(O)· 25%

CH3C(CHO)=CHCHO + h  H. + CH3CH=C(CHO)C(O)· 25%

CH3C(CHO)=CHCHO + h  HCO· + CH3C(CHO)=CH. 25%
Table 13 (continued)

47

Compound, reaction, and rate parameters Fraction

CH3C(CHO)=CHCHO + h  HCO· + CH3C(·)=CHCHO 25%

The photolysis reaction is assumed to have the same absorption cross-section and 

overall quantum yield as used for 2-butene-1,4-dial. The radical formation reactions 

shown above are assumed to have equal probability.

4-Oxo-2-penteneal

OH Rate Constant = 5.67e-11 cm3 molec-1s

-1

CH3C(O)CH=CHCHO + OH  CH3C(O)CH(OH)CH(·)CHO 37%

CH3C(O)CH=CHCHO + OH  CH3C(O)CH(·)CH(CHO)OH 37%

CH3C(O)CH=CHCHO + OH  H2O + CH3C(O)CH=CHC(O)· 26%

Rate constant from Bierbach et al (1994). Branching ratios estimated based on ratio of 

total rate constant relative to the rate constant for abstraction from CHO based on that 

derived for acrolein. Equal probability OH addition at the two positions about the 

bond is assumed.

O3 Rate Constant = 4.80e-18 cm3 molec-1s

-1

CH3C(O)CH=CHCHO + O3  CH3C(O)CHOO[excited] + HCOCHO 50%

CH3C(O)CH=CHCHO + O3  HCOCHOO[excited] + CH3C(O)CHO 50%

Rate constant from Liu et al (1999). Equal probability of reaction assumed for the two 

possible routes.

h Photolysis Set = 4OX2PEAL, Quantum yields = 1.

CH3C(O)CH=CHCHO + h  HCOCH=CHC(O)· + CH3· 25%

CH3C(O)CH=CHCHO + h  H. + CH3C(O)CH=CHC(O)· 25%

CH3C(O)CH=CHCHO + h  HCOCH=CH. + CH3C(O)· 25%

CH3C(O)CH=CHCHO + h  HCO· + CH3C(O)CH=CH. 25%

Absorption cross-sections from Calvert et al (2002). A high quantum yield is indicated 

by the photolysis rate measurements made in the Euphore chamber by Sørensen and 

Barnes (1998), and a unit quantum yield is assumed. Equal probability of reaction is 

assumed for the various possible radical formation routes shown above.

2-Methyl-4-oxo-2-pentenal

OH Rate Constant = 8.61e-11 cm3 molec-1s

-1

CH3C(O)CH=C(CH3)CHO + OH  CH3C(O)CH(OH)C(·)(CH3)CHO 62%

CH3C(O)CH=C(CH3)CHO + OH  CH3C(O)CH(·)C(CH3)(CHO)OH 21%

Rate constant and branching ratios are derived from estimated rate constants for 

reactions at various locations. Reaction by abstraction from CHO assumed to have 

same rate constant as the analogous reaction of acrolein. Addition to double bond 

calculated from OH addition rate constants for 4-oxo-2-pentenal x methacrolein / 

acrolein. The reaction shown is assumed to be the major addition process.

O3 Rate Constant = 2.00e-17 cm3 molec-1s

-1

CH3C(O)CH=C(CH3)CHO + O3  CH3C(O)CHOO[excited] + CH3C(O)CHO 30%

CH3C(O)CH=C(CH3)CHO + O3  CH3COO[excited]CHO + CH3C(O)CHO 70%

The rate constant estimated from O3 rate constants for 4-oxo-2-pentenal x 

methacrolein / acrolein. The branching ratios were derived by the mechanism 

generation system based on assignments for trisubstituted alkenes.

h Photolysis Set = 4OX2PEAL, Quantum yields = 1.

CH3C(O)CH=C(CH3)CHO + h  CH3· + CH3C(CHO)=CHC(O)· 25%
Table 13 (continued)

48

Compound, reaction, and rate parameters Fraction

CH3C(O)CH=C(CH3)CHO + h  H. + CH3C(O)CH=C(CH3)C(O)· 25%

CH3C(O)CH=C(CH3)CHO + h  CH3C(O)· + CH3C(CHO)=CH. 25%

CH3C(O)CH=C(CH3)CHO + h  HCO· + CH3C(·)=C(CH3)CHO 25%

The photolysis reaction is assumed to have the same absorption cross-section and 

overall quantum yield as used for 4-oxo-2-pentenal. The radical formation reactions 

shown above are assumed to have equal probability.

3-methyl 2,4-hexene-1,6-Dial

OH Rate Constant = 1.20e-10 cm3 molec-1s

-1

CH3C(=CHCHO)CH=CHCHO + OH  H2O + CH3C(=CHC(O)·)CH=CHCHO 12%

CH3C(=CHCHO)CH=CHCHO + OH  H2O + CH3C(=CHCHO)CH=CHC(O)· 12%

CH3C(=CHCHO)CH=CHCHO + OH  CH3C(=CHCHO)CH(·)CH(CHO)OH 75%

Rate constant and branching ratios estimated from sum of estimated rate constants for 

reactions at various positions. Rate constant for abstraction from CHO assumed to be 

same as for analogous reaction of acrolein. Rate constant for addition to double bond 

estimated from addition rate constant estimated from addition rate constant for 2,4-

hexene-1,6-dial x rate constant for isoprene / rate constant for 1,3-butadiene. The 

addition rate constant for 2,4-hexene-1,6-dial is estimated from the total rate constant 

of 9.00e-11cm3 molec-1s

-1

for that compound and the estimated rate constant for 

reaction at the CHO groups, based on the rate constant estimated for acrolein. The 

total rate constant for 2,4-hexene-1-6-dial is representative of values reported by Klotz 

et al (1995, 1999) for the trans,trans and the cis,trans isomers. The addition reaction 

shown is assumed to be the major process.

O3 Rate Constant = 2.01e-17 cm3 molec-1s

-1

CH3C(=CHCHO)CH=CHCHO + O3  CH3C(O)CH=CHCHO + 

HCOCHOO[excited]

25%

CH3C(=CHCHO)CH=CHCHO + O3  HCOCHO + CH3COO[excited]-CH=CHCHO 25%

CH3C(=CHCHO)CH=CHCHO + O3  HCOCHO + 

CH3C(CHOO[excited])=CHCHO

25%

CH3C(=CHCHO)CH=CHCHO + O3  CH3C(CHO)=CHCHO + 

HCOCHOO[excited]

25%

The rate constant is estimated from rate constants for 2,4-hexene-1,6-dial x isoprene / 

1,3-butadiene. The rate constant used for 2,4-hexene-1,6-dial is 1.00e-17 cm3 molec-1

s

-1

, based on the upper limit rate constant of Klotz et al (1995). Equal probability is 

assumed for reactions at the various positions, as shown above.
Table 13 (continued)

49

Compound, reaction, and rate parameters Fraction

6-oxo 2,4-heptadienal

OH Rate Constant = 7.51e-11 cm3 molec-1s

-1

CH3C(O)CH=CH-CH=CHCHO + OH  H2O + CH3C(O)CH=CH-CH=CHC(O)· 20%

CH3C(O)CH=CH-CH=CHCHO + OH  CH3C(O)CH=CH-CH(·)CH(CHO)OH 40%

CH3C(O)CH=CH-CH=CHCHO + OH  CH3C(O)CH(OH)CH(·)CH=CHCHO 40%

The rate constant and branching ratios estimated from estimated rate constants for 

reactions at various positions. Rate constant for abstraction from CHO assumed to be 

same as for analogous reaction of acrolein. Rate constant for addition to double bond 

assumed to be the same as the analogous reaction of 1,4-hexadiene-1,6-dial, derived as 

indicated above for 3-methyl-2-4-hexene-1,6-dial. The addition reactions shown are 

assumed to be the major processes, and equal probability for each is assumed.

O3 Rate Constant = 1.00e-17 cm3 molec-1s

-1

CH3C(O)CH=CH-CH=CHCHO + O3  CH3C(O)CHO + 

HCOCH=CHCHOO[excited]

25%

CH3C(O)CH=CH-CH=CHCHO + O3  HCOCH=CHCHO + 

CH3C(O)CHOO[excited]

25%

CH3C(O)CH=CH-CH=CHCHO + O3  HCOCHO + 

CH3C(O)CH=CHCHOO[excited]

25%

CH3C(O)CH=CH-CH=CHCHO + O3  CH3C(O)CH=CHCHO + 

HCOCHOO[excited]

25%

The rate constant is assumed to be the same as that assigned for 3,4-hexene-1,6-dial, 

based on the upper limit data of Klotz et al (1995). Equal probability of reaction at the 

various positions is assumed.

3,5-octadien-2,7-dione

OH Rate Constant = 6.02e-11 cm3 molec-1s

-1

CH3C(O)CH=CH-CH=CHC(O)CH3 + OH  CH3C(O)CH=CHCH(·)CH(OH)C(O)CH3

100%

The rate constant for addition to the double bond is assumed to be the same as that 

derived for 2,4-hexadiene-1,6-dial, as indicated above for 3-methyl-2,4-hexene-1,6-

dial. The reaction shown is assumed to be the major process.

O3 Rate Constant = 1.00e-17 cm3 molec-1s

-1

CH3C(O)CH=CH-CH=CHC(O)CH3 + O3  CH3C(O)CHO + 

CH3C(O)CH=CHCHOO[excited]

50%

CH3C(O)CH=CH-CH=CHC(O)CH3 + O3  CH3C(O)CH=CHCHO + 

CH3C(O)CHOO[excited]

50%

The rate constant is assumed to be the same as that assigned for 3,4-hexene-1,6-dial, 

based on the upper limit data of Klotz et al (1995). Equal probability of reaction at the 

various positions is assumed.
50

Figure 4. Action spectra for photodecompositions of 2-buene-1,4-dial, 4-oxo-2-penteneal and used 

for the model species AFG1 and AFG2.

Aromatic Ring Retaining Products

In addition to ring fragmentation, aromatics also react to form products where the 

aromatic ring is retained, such as phenols, cresols, aromatic aldehydes, and nitrophenols. Mechanisms for 

these species are included in the base mechanism, and are given in Table A-2 in Appendix A. The general 

methods used to represent these products are the same as employed in SAPRC-99, though rate constants 

and some mechanisms were updated. The various types of products that are represented, and changes 

relative to SAPRC-99, are summarized briefly below. Footnotes to Table A-2 document these reactions in 

more detail.

Phenols and Cresols. Although SAPRC-99 had a separate model species for phenol, in 

this mechanism the phenol and cresol model species are lumped together because representing phenol was 

found not to have a significant affect on model predictions for benzene, the only compound that forms 

phenol as a primary product in its reactions. The major atmospheric reactions of these compounds are 

with OH and NO3 radicals, with the latter generally being the more important sink under most conditions. 

Because very little was known about the mechanisms of these reactions at the time SAPRC-99 was 

developed, SAPRC-99 had very simplified and parameterized representations of these mechanisms, 

adjusted to fit results of a single o-cresol - NOx environmental chamber experiment. However, recently 

Berndt and Boge (2003) and Olairu et al (2003) determined that the major products of the reactions of OH 

with these compounds were various dihydroxybenzenes, and Olariu et al (2000) obtained rate constants 

for these compounds indicating that they were very reactive. However, if it was assumed that these were 

the major products of the OH + cresol reaction then the mechanism could not simulate the results of the ocresol - NOx chamber experiment. Because of this it was decided to defer updating the mechanism used 

for these compounds until more information is available, and the general parameterization used in 

SAPRC-99 for the reactions of the cresols was retained. The rate constants were updated and the 

parameters in the mechanism were re-adjusted to fit the data for the current mechanism.

Nitrophenols. As with SAPRC-99, the nitrophenol model species (NPHE) is used to 

represent the products formed in the NO3 + cresol reactions. In SAPRC-99 it was assumed that the major 

reactions of nitrophenols were with OH and NO3 radicals, as was the case with cresols. However, recent 

Wavelength (nm)

Action Spectrum (cm

-2

)

1e-21

1e-20

1e-19

1e-18

1e-17

300 350 400 450 500

2-butene-1,4-dial

4-Oxo-2-penteneal

AFG1 and AFG2

0.0e+0

5.0e-19

1.0e-18

1.5e-18

2.0e-18

2.5e-18

300 350 400 450 500
51

data presented by Barnes (2006) and Bejan et al (2006) indicate that photolysis is a major loss process for 

nitrophenols, with some of the photolysis resulting in the formation of HONO, but most forming 

unspecified products. Evidence was not given for significant reaction of nitrophenols with NO3 radicals, 

though the possibility that it may occur at least to some extent cannot necessarily be ruled out. Based on 

this, the current mechanism includes photolysis as a major sink for nitrophenols, and assumes that its 

reaction with NO3 radicals is not significant.

Aromatic Aldehydes. Benzaldehyde and similar aromatic aldehydes may be formed when 

OH abstracts from methyl groups of methylbenzenes, and these continue to be represented using the 

benzaldehyde (BALD) model species. Its mechanism is the same as used in SAPRC-99, though the rate 

constants were updated. The mechanism incorporates updated absorption cross sections for its photolysis 

to unspecified products, but the overall photodecomposition rate was not changed.

Non-Alkylbenzene Aromatics

The alkylbenzenes are not the only types of aromatics for which mechanisms were 

derived. Mechanism assignments were also made for styrenes, naphthalenes, tetralin, various halo- and 

nitro-benzenes, phthalates, and other aromatic-containing compounds. The derivation of the mechanisms 

for these compounds is summarized on Table 14, the rate constants are given in Table B-2 and Table B-4, 

and the mechanisms are given in Table B-2 in Appendix B. As indicted on Table B-4, some of these are 

based on the general procedures derived for the alkylbenzenes as discussed above, while others (e.g., 

styrenes, naphthalenes, tetralin, and the isocyanates) appear to have quite different mechanisms. In those 

cases mechanisms are derived based on considerations for the individual compounds (as with the 

styrenes), or parameterized mechanisms, that were adjusted to fit environmental chamber data, were used. 

Other non-alkylbenzene aromatics are represented using the lumped molecule method 

based on mechanisms for aromatics for which mechanism assignments were made. These are discussed in 

the "Lumped Molecule Representation" section, below.

Reactions with Chlorine

Alkylbenzenes. The low rate constant for the reaction of chlorine atoms with benzene 

(1.3 x 10-16 cm3 molec-1s

-1

, Sokolov et al, 1998), indicates that the only significant reactions of Cl with 

aromatics are abstractions off the aromatic ring. The rate constants for these reactions have been 

measured for some of the methylbenzenes (see Table 4) and can be estimated for other alkylbenzenes 

using the group-additivity parameters given on Table 3. The products formed are expected to be aromatic 

aldehydes that are represented using the benzaldehyde (BALD) model species if the reaction is on a 

methyl group, or primarily various aromatic ketones that are represented by the lumped higher ketone 

model species (PROD2), plus organic nitrates formed in the peroxy + NO reaction or hydroperoxides 

formed in the peroxy + HO2 reaction. These result from reactions of the same radicals formed when OH 

radicals react off the aromatic ring, and the mechanisms can be derived in the same way, except for the 

different branching ratios for the initial reactions at the various positions, where applicable.

Chlorine + alkylbenzene mechanisms were derived in this manner for all the 

alkylbenzenes that are used to derive parameters for the lumped model species ARO1 and ARO2, as 

discussed below. The rate constants and mechanisms so derived are given in Table B-7 in Appendix B. 

Table 14. Discussion of mechanisms for the non-alkylbenzene aromatic compounds that for which 

mechanistic assignments have been derived. The rate constants and additional 

documentation are given in Table B-4 and the reactions are given in Table B-2 in 

Appendix B. 

Compound Reacts With (reaction type)
Table 14 (continued)

52

Styrene OH, O3, NO3, O3P (double bond reaction only)

Mechanism as described by Carter et al (1999b) was used, except for some minor rate constants 

updates and the overall nitrate yield being increased from 13% to 18% to improve simulations of 

incremental reactivity data with styrene with the current mechanism. Results of model simulations of 

the chamber experiments with this compound are summarized on Table 23 in the Mechanism 

Evaluation Results section.

-Methyl styrene OH, O3, NO3, O3P (double bond addition only)

Assumed to react analogously to the mechanism derived for styrene. The nitrate yield in the OH 

reaction was increased to correspond to the additional carbon.

Monochlorobenzene OH (100% ring addition)

p-Dichlorobenzene OH (100% ring addition)

Hexafluorobenzene OH (100% ring addition)

Nitrobenzene OH (100% ring addition)

The products formed in the reactions of these compounds are represented by those formed from in the 

reactions of OH with benzene. The appropriate measured rate constants for the compounds were used.

Benzotrifluoride OH (100% ring addition)

p-Trifluoromethyl-Cl-benzene OH (100% ring addition)

The reaction is assumed to proceed only by addition of OH to the aromatic ring. The products formed 

are represented by those formed in the ring-addition reactions of toluene, as shown on Table 11. The 

nitrate yields in the reactions of the peroxy radicals are also assumed to be the same as used for 

toluene.

Benzyl Alcohol OH (70% ring addition)

The mechanism and environmental chamber data for this compound are discussed by Carter et al 

(2005a). The measured concentrations of benzaldehyde in the chamber experiments are consistent 

with a fraction reacted by abstraction from the -CH2OH of 30%, which is assumed in the mechanism. 

This is formed by O2 reacting with the BzCH(·)OH radical forming benzaldehyde + HO2 without NO 

to NO2 conversions or nitrate formation. The products formed following the addition to the aromatic 

ring are assumed to be the same as used for ethylbenzene, as shown on Table 11. The nitrate yield 

factor derived for toluene is used for the peroxy reactions involved in the ring addition mechanism. 

Results of model simulations of the benzyl nitrate experiments are summarized on Table 23 in the 

Mechanism Evaluation Results section.

Methoxybenzene; Anisole OH (93% ring addition)

m-Nitrotoluene OH (60% ring addition)

The fraction reacting by addition to the aromatic ring is estimated from the difference between the 

measured total OH rate constant and the rate constant for abstraction off the ring estimated using 

group-additivity methods as shown on Table 3. The products formed following ring addition are 

represented by those formed from ring addition to toluene, as shown on Table 11. The products 

formed from reaction off the ring are represented by the lumped higher oxygenated product PROD2 

in the case of methoxybenzene and by the aromatic aldehyde species BALD in the case of mnitrotoluene. The nitrate yield factor of toluene was assumed.

2-Phenoxyethanol; Ethylene glycol phenyl ether OH (54% ring addition)

The total rate constant was estimated by the sum of the estimated rate constants for addition to the 

aromatic ring and abstraction reactions off the aromatic ring. The latter was estimated using the 

group-additivity methods shown in Table 3, and the products formed were derived using the estimates 

and procedures incorporated in the mechanism generation system. The rate constant and products for 
Table 14 (continued)

53

the ring addition reaction were assumed to be the same as derived for methoxybenzene, as discussed 

above.

1,2-Diacetyl benzene OH (100% ring addition)

100% ring addition is assumed – reaction on the methyl group is assumed to be relatively slow. The 

products formed are represented by those formed in the mechanism for OH ring addition to o-xylene, 

except that the nitrate yield factor for a C10 compound, shown on Figure 3, was used.

Phthalic anhydride OH (100% ring addition)

The rate constant was assumed to be the same as the measured rate constant for 1,2-diacetyl benzene. 

The products formed are also represented by those formed in the mechanism for OH ring addition to 

o-xylene, except that the nitrate yield factor for a C8 compound, shown on Figure 3, was used. 

Diethyl phthalate OH (71% ring addition)

Dibutyl phthalate OH (47% ring addition)

The total rate constant was estimated by the sum of the estimated rate constants for addition to the 

aromatic ring and abstraction reactions off the aromatic ring. The latter was estimated using the 

group-additivity methods shown in Table 3, and the products formed were derived using the estimates 

and procedures incorporated in the mechanism generation system. The rate constant and products for 

the ring addition reaction were assumed to be the same as derived for 1,2-diacetylbenzene, as 

discussed above, except that the nitrate factors appropriate for the carbon numbers of the particulate 

compounds, shown on Figure 3, were used.

2-Ethylhexyl benzoate OH (20% ring addition)

The rate constant for reaction at the aromatic ring estimated to be the same as the total rate constant 

for acetophenone (as tabulated by Atkinson, 1989), assuming that ring addition is the major reaction 

for that compound. The mechanism for reaction at aromatic ring based on that of toluene. The rate 

constant and mechanism for reaction at groups off the aromatic ring based on those estimated for 2-

ethyl hexyl acetate, since reaction at the acetate group is estimated to be negligible for that 

compound.

Naphthalene OH (parameterized)

Tetralin OH (parameterized)

2,3-Dimethyl naphthalene OH (parameterized)

The details of the mechanisms for these compounds are still too uncertain to attempt to derive more 

explicit predictive mechanisms. The highly parameterized representations employed in SAPRC-99 

(Carter, 2000a) are retained, though the values of the parameters were re-adjusted to fit the chamber 

data with the current mechanism. As discussed by Calvert (2002), the mechanisms for the reactions of 

these compounds are expected to be affected by total NO2 levels, since competitions apparently exist 

between reactions with O2 and NO2 for some of the intermediate radicals. In order to avoid 

introducing new model species into the mechanism to represent speculative and uncertain processes, 

this NOx dependence is in effect represented in SAPRC-99 and SAPRC-07 by using formation of 

lumped peroxyacetyl radicals (RCO3) in the parameterized mechanism. Results of adjusted model 

simulations of the chamber data with these compounds are summarized on Table 23 in the 

Mechanism Evaluation Results section.

Methyl naphthalenes OH (parameterized)

Estimated mechanism derived by averaging the parameters for naphthalene and 2,3-

dimethylnaphthalene, as was the procedure used when deriving the mechanism for this compound for 

SAPRC-99.
Table 14 (continued)

54

Furan

2-Methyl furan

3-Methyl furan

2,5-Dimethyl furan

As discussed in the Introduction, chamber experiments were carried out for several furans as part of 

this project because their initial reactions are expected to form unsaturated 1,4-dicarbonyls in high 

yield, which as discussed above are believed to be important photoreactive products formed in the 

oxidations of the aromatic hydrocarbons. The expected mechanism is as follows, using furan as the 

example:

O

HC

C

H

C

H

CH

O

HC

C

H

C

H

 

CH

OH O

HC

C

H

C

H

CH

 

HO O

HC

C

H

C

H

CH

O

OH O2

HO2

Model simulations of experiments with these compounds could therefore serve as a means to evaluate 

mechanisms for the individual unsaturated 1,4-dicarbonyls without the uncertainties involved with 

handling these highly reactive compounds directly. However, there was insufficient time and 

resources available to this project to complete the development of explicit mechanisms for aromatics 

and their ring-opening products, so the evaluation of mechanisms using experiments with these 

compounds will be completed in future projects. For this version of the mechanism, the unsaturated 

1,4-dicarbonyls expected to be formed from these furans were represented using the same approach as 

used for the aromatic hydrocarbons, i.e., by the AFG1 and AFG2 model species with their relative 

yields adjusted to fit the chamber data. Results of adjusted model simulations of the chamber data 

with this compound are summarized on Table 23 in the Mechanism Evaluation Results section. 

2,4-Toluene Di-isocyanate (TDI) OH (parameterized)

The details of the mechanism of this compound, which was found by Carter et al (1997d) to be a

strong radical inhibitor, are unknown. The parameterized mechanism used by Carter et al (1997d) to 

fit the chamber data, which is retained in SAPRC-99, is still retained for SAPRC-07, though the 

parameters were re-adjusted to fit the data with the current base mechanism. Results of adjusted 

model simulations of the chamber data with this compound are summarized on Table 23 in the 

Mechanism Evaluation Results section.

Para Toluene Isocyanate (PTI) OH (parameterized)

This was experimentally studied by Carter et al (1999a) as a model compound from which to derive 

an estimated mechanism for MDI, which has too low a volatility to be studied experimentally. Like 

TDI, the mechanism for this compound is unknown and Carter et al (1999a) derived a highly 

parameterized mechanism to fit the chamber data. This was used in SAPRC-99 and is retained in 

SAPRC-07, but with the parameters re-adjusted to fit the data for the current mechanism. Results of 

adjusted model simulations of the chamber data with this compound are summarized on Table 23 in 

the Mechanism Evaluation Results section.

Methylene Diphenylene Diisocyanate (MDI) OH (parameterized)

The mechanism for this compound was derived from the PTI mechanism as discussed by Carter et al 

(1999a). Based on structural considerations, the rate constant is assumed to be twice that for PTI, but 

the same set of products is assumed to be formed.
55

Aromatic Products. Reactions of chlorine atoms with the -dicarbonyls and the aromatic 

ring-retaining products are included in the base chlorine mechanism, as shown in Table A-5 in Appendix 

A. Footnotes to that table document the sources of the rate constants and mechanisms that were used. 

Although the unsaturated dicarbonyls represented by AFG1-3 undoubtedly react relatively rapidly with 

chlorine atoms, these reactions are ignored in the base chlorine mechanisms. This is because it is expected 

that the other reactions would be more important sinks for these products under most atmospheric 

conditions, and their high reactivity would result in low concentrations that would make them 

unimportant as sinks for chlorine atoms. This is probably true for the -dicarbonyls as well, though their 

chlorine reactions are included.

Mechanisms for Amines

Amines react relatively rapidly with OH radicals, and are also expected to relatively rapidly with 

NO3, based on a relatively high rate constant for reaction of NO3 with 1-methyl-2-pyrrolidinone 

(Aschmann and Atkinson, 1999). Rate constant data of Tuazon et al (1994) suggests that the reaction with 

O3 may also be non-negligible for some amines. Mechanisms for all three of these types of reactions were 

derived, as discussed by Carter (2008a) and summarized below.

In the case of the OH and NO3 reactions, the reaction is assumed to proceed by H-atom 

abstraction from the amino group or from the group next to the amino group, forming HNO3 and the 

corresponding carbon- or nitrogen-centered radicals. Group-additivity parameters that can be used to 

estimate rates of these reactions are given in Table 3, above, and footnotes to that table indicate how these 

parameters were derived. Table 3c indicates that the group-additivity methods can estimate the rate 

constants to within 26% on the average.

The subsequent reactions of the carbon-centered radicals formed in these reactions can be derived 

using the mechanism generation system as employed for other compounds, except that estimates need to 

be made for reactions of -amino alkoxy radicals, e.g., RCH[O·]-NHR'. Although this is uncertain, to 

simplify the mechanism generation we assume that decompositions forming N-centered radicals, e.g., 

RCH[O·]-NHR'  RCHO + R'NH·, and estimate the relative rates of reactions for the competing routes 

based on estimates for other radicals considered to be similar. The applicable radicals and reactions 

assumed to dominate when generating mechanisms for amines in the current version of the mechanism 

are indicated on Table 15 These assumptions are uncertain, though alternative assumptions probably do 

not yield mechanisms with significantly different reactivities.

The subsequent reactions of the nitrogen-centered radicals formed after H-abstraction from NH2

or NH groups depends on whether there is an abstractable hydrogen in the -position to the amine. If 

there is, then it is assumed that the dominant reaction is abstraction of this hydrogen by O2, forming HO2

and the corresponding C=N compound, e.g.,

RCH2NH· + O2  HO2 + RCH=NH

This is based on kinetic data obtained by Lindley et al (1979) for reactions of (CH3)2N· with O2, NO, and 

NO2, where the reaction with O2, forming HO2 + CH3-N=CH2, is calculated to dominate under 

atmospheric conditions.

The subsequent reactions of the C=N products formed in this reaction are unknown and therefore 

this is an additional source of uncertainty in the mechanism. These are expected to be reasonably reactive 

compounds. For the current mechanism, they are represented by the generic reactive non-aldehyde 

oxygenated species PROD2. The appropriateness of this representation is highly uncertain.
56

Table 15. Assignments made for alkoxy radical intermediates predicted to be formed in the 

photooxidation mechanisms of the amines. 

Radical Reaction Assumed to Dominate

·OCH2-NH2 + O2 HCO-NH2 + HO2·

CH3-NH-CH2O· + O2 CH3-NH-CHO + HO2·

.OCH2CH2-NH2 HCHO + .CH2-NH2

CH3CH(O·)NH2 + O2 CH3C(O)NH2 + HO2·

CH3-N(CH3)CH2O· + O2 CH3-N(CH3)CHO + HO2·

NH2CH(O·)CH2OH HCO-NH2 + .CH2OH

CH3C(O·)(CH3)NH2 CH3C(O)NH2 + CH3·

CH3C(CH3)(CH2O·)NH2 HCHO + CH3C(·)(CH3)NH2

CH3-N(CH2O·)CH2CH2OH CH3-N(CH2OH)CH2CH(·)OH

CH3C(CH2O·)(NH2)CH2OH + O2 CH3C(CHO)(NH2)CH2OH + HO2·

.OCH2CH2CH(NH2)CH2OH NH2CH(CH2CH2OH)CH(·)OH

CH3-N(CH3)CH(O·)CH2OH CH3-N(CH3)CHO + .CH2OH

CH3CH(O·)CH(NH2)CH2OH CH3CHO + NH2CH(·)CH2OH

CH3CH2C(O·)(NH2)CH2OH CH3CH2C(O)NH2 + .CH2OH

HOCH2CH2-NH-CH(O·)CH2OH HCO-NH-CH2CH2OH + .CH2OH

CH3CH2-N(CH2CH3)CH2CH2O· CH3CH2-N(CH2CH2OH)CH(·)CH3

CH3CH2-N(CH2CH3)CH(O·)CH3 CH3CH2-N(CH2CH2·)CH(CH3)OH

CH3CH2-N(CH2CH2O·)CH(CH3)OH CH3CH(·)N(CH2CH2OH)CH(CH3)OH

CH3CH2-N(CH2CH2OH)CH(O·)CH3 CH3CH2-N(CH2CH(·)OH)CH(CH3)OH

CH3CH(O·)N(CH2CH2OH)CH(CH3)OH CH3CH(OH)N(CH2CH(·)OH)CH(CH3)OH

HOCH2CH2-N(CH2CH2OH)CH(O·)CH2OH HCO-N(CH2CH2OH)CH2CH2OH + .CH2OH

CH3CH(OH)CH2-N(CH2CH(CH3)OH)CH2-

CH(CH2O·)OH

HCHO + CH3CH(OH)CH2-N(CH2CH(·)OH)CH2CH-

(CH3)OH

CH3CH(OH)CH2-N(CH2CH(CH3)OH)-

CH(O·)CH(CH3)OH

CH3CH(OH)CH2-N(CHO)CH2CH(CH3)OH + 

CH3CH(·)OH

The above type of reaction cannot occur if the nitrogen-centered radical lacks an abstractable 

hydrogen in the -position, as is the case in radicals predicted to be formed in the reactions of t-butyl 

amine and 2-Amino-2-Methyl-1-Propanol (AMP). In this case, the only expected reactions of the 

nitrogen-centered radical is reaction with NO, NO2, or HO2, e.g.,

(CH3)3CNH· + NO  (CH3)3CNHNO (a)

(CH3)3CNH· + NO2  (CH3)3CNHNO2 (b)

(CH3)3CNH· + HO2  O2 + (CH3)3CNH2 (c)

If NOx is present, the major reaction is expected to be process (b), forming the nitramine, since the 

nitrosamine formed in process (a) is expected to undergo rapid photolysis back to NO and the radical, 

resulting in no net reaction. Since this is a radical inhibiting process, this mechanism predicts that t-butyl 

amine and AMP would be radical inhibitors, since reaction forming the N-centered radical is estimated to 

be the major initial reaction. This is consistent with the fact that these compounds are indeed found to be 

strong ozone and radical inhibitors in environmental chamber experiments (Carter, 2008a)

For implementation in the mechanism, the model species "NRAD" is used to represent the 

reactions of the N-centered radicals that lack abstractable hydrogens in the  position. This species is 
57

representing as reacting with NO2 to form a nitramine, with a rate constant estimated by assuming that it 

is the same as for the reaction of NO2 with the generic higher acyl peroxy radical species RCO3. The 

nitramine is approximately represented by PROD2 in the current mechanism, though the appropriateness 

of this representation is also highly uncertain. The reaction with NO, forming the nitrosoamine, is 

neglected because of the expected rapid photolysis of the nitrosoamine to reverse the reaction. In the 

absence of NOx, the NRAD is represented as reacting with HO2 to re-form the amine, with a rate constant 

assumed to be the same as used for the reaction of RCO3 with HO2. Because of the way the mechanism is 

implemented it is not practical to represent the amine formed in the reaction as the amine itself, so its 

subsequent reactions are therefore neglected. This is because the two amines represented to form NRAD 

are inhibitors, so representing them with reactive product model species such as PROD2 is inappropriate.

Methods for estimating rate constants and mechanisms for the reactions of O3 with amines were 

also derived. These are discussed in detail by Carter (2008a) and briefly summarized here. Based on the 

available rate constants of Tuazon et al (1994) and limited information concerning the products given by 

Tuazon et al (1994) and Murphy et al (2007), Carter (2008a) estimates that the initial reaction of O3 with 

amines is at the group next to the amino group, ultimately resulting in abstraction from  C-H bonds, 

forming OH radicals and the same types of radicals as formed in the OH reaction, e.g.,

CH3NH2 + O3  [adduct?]  O2 + OH + ·CH2NH2

The available kinetic data for the methylamines and DMAE are fit by

K(group,O3) = 10

-42.97 - {5.84 k(group,OH)}

,

where k(group) refers to net H-atom abstraction at a group adjacent to the amino group and the rate 

constants are in cm3 molec-1s

-1

. This gives estimates for rate constants that agree with those of Tuazon et 

al (1994) to within a factor of two. This was also used as the basis for estimating relative rates of reaction 

at different positions secondary or tertiary amines that have non-equivalent substituents. The subsequent 

reactions of the radicals formed are derived as discussed above for the OH and NO3 mechanisms.

A significant uncertainty in terms of calculations of the atmospheric ozone impacts of the amines 

concerns the extent to which they react with gas-phase HNO3, forming the amine salt. If this reaction is 

sufficiently fast, and if most of the salt formed partitions to the vapor phase, then the amine would not be 

available to react in the gas phase and promote ozone formation. Although model simulations of the 

available environmental chamber experiments with amines are not sensitive to this reaction because the 

amount of HNO3 formed in the experiments is small compared to the amount of amine added, the 

atmospheric incremental reactivity simulations are very sensitive to this because of the amount of amine 

added is relatively small compared to the amount of HNO3 predicted to be formed (Carter, 2008a). The 

importance of this under atmospheric conditions is difficult to estimate because of uncertainties and 

variabilities concerning sources and sinks for HNO3 in the atmosphere. As discussed by Carter (2008a) in 

order to obtain upper limit magnitude estimates for the ozone impacts of the amines we assume that 

removal of the amines by reaction with HNO3 is negligible, but this is likely not to be the case in actual 

atmospheres.

Miscellaneous Assigned Mechanisms

There are several compounds for which mechanisms have been derived where the procedures 

discussed above could be employed. In those cases, mechanisms were derived based on considerations of 

the relevant reactions of the particular compounds, or, if the details of the reactions for the particular 

compound are sufficiently uncertain, parameterized mechanisms were derived and adjusted to fit 

available environmental. These compounds are listed in Table 16, along with a brief discussion of how 
58

Table 16. Discussion of mechanisms for miscellaneous compounds that were not derived using the 

procedures discussed previously in this report. The rate constants, reactions, and 

additional documentation are given in Table B-2, and Table B-4 through Table B-6 in 

Appendix B. 

Compound Reacts With

N-Methyl-2-Pyrrolidone OH, NO3

Mechanism based on that originally developed by Carter et al (1996b), using the kinetic data of 

Aschmann and Atkinson (1999). The SAPRC-99 mechanism had an incorrect conversion of the 

original mechanism that did not incorporate all the NO to NO2 conversions in the OH and NO3

reactions, and compensated for this by reducing the overall nitrate yield to fit the chamber data. Once 

this was corrected, the chamber data are best fit using the nitrate yield originally derived by Carter et 

al (1996b). Note that the (presumably incorrect) SAPRC-99 mechanism fit some of the chamber data 

somewhat better than the original and the current updated mechanism, but is not as consistent with 

our current estimation of the chemistry. Results of model simulations of the chamber experiments 

with this compound are summarized on Table 23 in the Mechanism Evaluation Results section.

Dimethyl Sulfoxide OH, NO3

Environmental chamber experiments and possible mechanisms for DMSO reactions were discussed 

by Carter et al (2000d). No mechanism that was entirely consistent with the available data was found, 

but the best fit "Mechanism C", as adopted for the ambient reactivity calculations given by Carter et 

al (2000d) is retained for this version of the mechanism. Results of model simulations of the chamber 

experiments with this compound are summarized on Table 23 in the Mechanism Evaluation Results 

section.

1,3-Butadiyne OH, NO3

It is assumed that the primary reaction is OH or NO3 adding to terminal position, forming an allylicstabilized radical. In the case of the OH reaction, the 1,2-unsaturated alpha-hydroxy radical reacts 

with O2 to form HO2 and 1,2-butadien-4-al, and in the case of the NO3 reaction the analogous 

compound reacts unimolecularly to form NO2 and the same aldehyde. The aldehyde is represented by

RCHO, on the basis that this is probably not as bad an approximation as MACR. It is assumed that 

the reaction with O3 is slow. 

Methyl Bromide OH

Ethyl Bromide OH

1,2-Dibromoethane OH

n-Propyl Bromide OH

n-Butyl Bromide OH

The mechanisms for these compounds are approximated by that of the corresponding chloride, but 

with the appropriate OH rate constant for the compound. This may somewhat overestimate the 

reactivity of the compounds, and may underestimate inhibition under low NOx conditions. This can 

be considered to be useful for upper-limit mechanism estimates, but will need to be refined for "best 

estimate" reactivity estimates. Results of model simulations of the chamber experiments with npropyl bromide and n-butyl bromide, summarized on Table 23 in the Mechanism Evaluation Results 

section, are consistent with this assessment.

Hexamethyldisiloxane OH

D4 Cyclosiloxane OH

Hydroxymethyldisiloxane OH

Parameterized mechanisms adjusted to fit the incremental reactivity chamber data of Carter et al 

(1992) that were considered to be suitable for mechanism evaluation are employed. (Several runs had 
Table 16 (continued)

Compound Reacts With

59

no assigned initial NO2 concentrations or non-standard run conditions, and were not used.) No 

chemically reasonable mechanism was found that was consistent with the data (Carter et al, 1992), so 

a highly simplified parameterized mechanism, which assumes an adjustable amount of radical loss 

and the remainder of the reaction forming HO2 after an NO to NO2 conversion, and assumes no 

reactive products formed, was used. Results of model simulations of the chamber experiments with 

these compounds are summarized on Table 23 in the Mechanism Evaluation Results section.

D5 Cyclosiloxane OH

Although reactivity chamber experiments were conducted for this compound (Carter et al, 1992), 

none of these runs were considered suitable for mechanism evaluation because of uncertainties 

concerning initial NOx concentrations. Qualitatively the results were similar to those for D4 

cyclosiloxane in that large inhibition was assumed. The amount of inhibition used was assumed to be 

approximately the same as that derived for D4, since a similar mechanism is expected.

Acrylonitrile OH

The data of Hashimoto et al (1984) indicate that the products are formaldehyde and HCO-CN after an 

NO to NO2 conversion. HCO-CN is assumed to be relatively unreactive, which is supported by the 

concentration-time profiles reported by Hashimoto et al (1984). Reactions with NO3 and O3 are 

assumed to be relatively slow, though no data are available concerning these reactions.

Methyl nitrite OH, h

The reaction with OH is assumed to proceed by abstraction from the methyl group, followed by 

decomposition to form NO and formaldehyde. The photolysis absorption cross sections are from 

Calvert and Pitts (1966). The major reaction pathway is photolysis, which is assumed to form methyl 

radicals and NO with unit quantum yields.

Chloropicrin h

Carbon disulfide OH, h

Methyl isothiocyanate OH, h

EPTC (S-Ethyl dipropylthiocarbamate) OH, NO3

Molinate OH, NO3

Pebulate OH, NO3

Thiobencarb OH, NO3

The mechanisms for these pesticide VOCs as given by Carter and Malkina (2007) are used without 

modifications other than adaptation to this version of the mechanism. Results of model simulations of 

the chamber experiments with these compounds are discussed in the Mechanism Evaluation Results 

section.

trans 1,3,3,3-Tetrafluoropropene OH

2,3,3,3-Tetrafluoropropene OH

The mechanisms derived for these compounds and evaluated against chamber data by Carter (2009a) 

and Carter (2009b), respectively, were used.

Ethyl methyl ketone oxime OH

An estimated mechanism was derived explicitly for this compound. About 24% of the reaction is 

assumed to occur at the methyl or CH2 groups, with the subsequent reactions estimated using the 

procedures in the mechanism generation system. The remainder of the reaction is assumed to be 

addition of OH to the C=N double bond, which is assumed to form primarily

C2H2C(CH3)(OH)N(.)OH, which is assumed to react with O2 to form C2H5C(CH3)(OH)NO + HO2. 
Table 16 (continued)

Compound Reacts With

60

The rate constant is estimated by the rate constant for OH + isobutene x the average of the ratio of the 

rate constants for CH2=NOH / Ethene and CH3CH=NOH / Propene, with abstractions from the 

methyl group subtracted off. The CH2=NOH and CH3CH=NOH rate constants are from the tabulation 

of Atkinson (1989). The C2H5C(CH3)(OH)NO is assumed to photolyze rapidly, forming NO + an 

alpha-hydroxy radical that reacts with O2 to form MEK and HO2. The absorption cross-sections and 

quantum yields are unknown, but photolysis is assumed to be relatively rapid, and estimated to be 

comparable to that of methyl nitrite.

Methyl iodide OH, h

The mechanism for this compound as given by Carter (2007) was used without modification. This 

mechanism, and the reactions of the inorganic iodine species formed in both the OH and photolysis 

reactions, are also included in Table B-2, with is available with the electronic version of this report. 

Results of model simulations of the chamber experiments with these compounds are discussed by 

Carter (2007) and summarized in the Mechanism Evaluation Results section.

the mechanisms were derived. The initial rate constants are given in Table B-4 and their reactions are 

given in Table B-2 in Appendix B, along with notes giving references for the rate constants and in some 

cases the mechanisms. The references cited can be consulted for additional information concerning the 

derivation of the mechanisms for these compounds.

Lumped Molecule Representations

A number of compounds or classes of compounds do not have explicit mechanistic assignments 

in the SAPRC-99 or SAPRC-07 mechanisms, but instead are represented by the "lumped molecule" 

approach for the purpose of estimating their reactivities or contributions to mixtures. In this approach, the 

impacts of a compound or class of compounds are assumed to be the same, on a per-molecule basis, as a 

compound or group of compounds for which a mechanism has been derived. This is used for compounds 

whose reactivities or impacts are of interest, but are either not considered to be sufficiently important to 

have an explicit mechanism derived, or whose mechanism is considered to be not significantly different 

from that for the compound representing it, or where the mechanistic difference with the representing 

compound is considered to be small compared to the uncertainty of the mechanism. It is also used for 

unspeciated mixtures of isomers, where a representative compound or group of compounds is used to 

estimate the impact of the mixture.

The SAPRC-07 lumped molecule representations are given in Table B-9 in Appendix B. In most 

cases the same representations are used in SAPRC-07 as implemented in SAPRC-99 (Carter, 2000a). The 

exceptions are primarily compounds or groups of compounds for which mechanisms have since been 

assigned, the representation of the higher alkylbenzenes, and the new detailed model species that have 

been added. The compounds or mixtures that were previously represented using the lumped molecule 

approach but now have mechanistic assignments are furan and lumped higher alkylbenzene species as 

discussed above in conjunction with the aromatics mechanisms. The new lumped aromatic model species 

is used to give a better lumped molecule representation for the higher aromatics that is more appropriate 

to their carbon numbers than by representing them using methylbenzenes or ethylbenzene, as was the case 

previously. In addition, a total of 31 new types of compounds that were not represented in SAPRC-99 are 

now represented in SAPRC-07 using the lumped molecule approach.

The lumped molecule assignments shown on Table B-9 are used to estimate the atmospheric reactivities 

of these compounds or mixtures, and are also used where applicable to derive the mechanisms for the 
61

lumped mechanisms in airshed models based on mixtures containing them, as discussed in the following 

section.

Lumped Mechanisms for Airshed Models

Airshed model applications require simulations of highly complex mixtures of large numbers of 

VOCs, and in most cases it is not necessary or practical to represent each of them separately. For such 

applications, models with lumped model species that represent reactions of a large number of species with 

similar reaction rates and mechanisms are generally employed. Even for VOC reactivity assessment it is 

only really necessary to separately represent the VOC whose reactivity is being assessed, with the 

reactions of most of the other VOCs present in the ambient simulation being represented using 

appropriate lumped model species. This is the approach used in the SAPRC-99 mechanism, and is 

retained for SAPRC-07. The lumping approach and recommended set of lumped model species is also 

unchanged in this version of the mechanism.

Adjustable Parameter Mechanisms

The SAPRC-99 mechanism has the option to vary the lumping approach in terms of the number 

of model species used and how they are lumped, and also to vary the mixture of compounds used to 

derive the parameters for the lumped model species, based on the emissions in model scenario or other 

considerations (Carter, 2000a,b; Adleman et al, 2005). This is referred to as the "adjustable parameter" 

mechanism for airshed models. This feature is retained in this version of the mechanism, with the 

procedures and software for adjustable parameter SAPRC-07 being the same as employed for SAPRC-99, 

as discussed by Carter (2000a) and Adleman et al (2005). The data files implementing the variable 

parameter version of SAPRC-07 will be made available at the Speciation Database website1and the 

SAPRC mechanism website2. The files will have the same format as those currently used to implement 

SAPRC-99.

Fixed Parameter Mechanism

In practice most model applications have used the "fixed parameter" version of SAPRC-99. This 

involves use of a fixed set of lumped model species, with the parameters for the adjustable parameter 

lumped species being derived using a pre-defined mixture. The updates to the fixed parameter mechanism 

for SAPRC-07 are documented in the remainder of this section.

The lumped model species and general lumping approach used in fixed parameter SAPRC-99 is 

the retained in SAPRC-99. The list of lumped and explicit model species used for representing various 

types of emitted VOCs is given in Table 17, and lumped model species added to the base mechanism for 

the fixed parameter mechanism are included in Table A-1 in Appendix A. These include the lumped 

model species that are added to the base mechanism whose parameter can be adjusted based on the 

emissions mixture being represented, the organic product model species already in the base mechanism 

that are also used to represent various types of primary emitted organics, and the model species for 

compounds that are explicitly represented. In all cases the lumped or explicit species represent the emitted 

compound on a mole-for-mole basis; there is no "reactivity weighting" in this version of the mechanism.

 

1 The Speciation Database website is at http://www.cert.ucr.edu/~carter/emitdb.

2 The SAPRC mechanism web site is at http://www.cert.ucr.edu/~carter/SAPRC.
62

Table 17. List of model species used in the lumped mechanism for airshed models for representing 

the various types of emitted VOCs.

 Name Description Amount in 

Base ROG [a]

Lumped model species added to the base mechanism. Parameters can optionally be 

adjusted based on mixture being represented.

ALK1 Alkanes and other non-aromatic compounds that react only with OH, and 

have kOH (OH radical rate constant at 300oK) between 1.36 and 3.41 x 

10-13 cm3 molec-1s

-1

. (Primarily ethane)

17.7

ALK2 Alkanes and other non-aromatic compounds that react only with OH, and 

have kOH between 3.41 x 10-13 and 1.70 x 10-12 cm3 molec-1s

-1

. 

(Primarily propane)

14.8

ALK3 Alkanes and other non-aromatic compounds that react only with OH, and 

have kOH between 1.70 and 3.41 x 10-12 cm3 molec-1s

-1

.

27.7

ALK4 Alkanes and other non-aromatic compounds that react only with OH, and 

have kOH between 3.41 and 6.81 x 10-12 cm3 molec-1s

-1

.

35.5

ALK5 Alkanes and other non-aromatic compounds that react only with OH, and 

have kOH greater than 6.81 x 10-12 cm3 molec-1s

-1

.

18.8

ARO1 Aromatics with kOH < 1.36 x 10-11 cm3 molec-1s

-1

. 12.9

ARO2 Aromatics with kOH > 1.36 x 10-11 cm3 molec-1s

-1

.. 17.2

OLE1 Alkenes (other than ethene) with kOH < 4.77 x 10-11 cm3 molec-1s

-1

. 11.3

OLE2 Alkenes with kOH > 4.77 x 10-11 cm3 molec-1s

-1

. 12.5

TERP Terpenes 0.7

Lumped organic product model species that are already in the base mechanism that are 

also used to represent certain types of primary emitted VOCs. (Mechanisms are not 

adjustable)

RCHO C3+ saturated aldehydes 2.9

MEK Ketones and other non-aldehyde oxygenated compounds with kOH 

between 5 x 10-13 and 5 x 10-12 cm3 molec-2sec-1.

1.2

PROD2 Ketones and other non-aldehyde oxygenated compounds with greater than 

5 x 10-12 cm3 molec-2sec-1.

RCOOH C3+ organic acids

MGLY Methyl glyoxal and C3+ -dicarbonyl aldehydes

BACL Biacetyl and other highly photoreactive compounds that are not otherwise 

represented.

CRES Phenols and cresols

BALD Aromatic aldehydes 0.2

MACR Acrolein and methacrolein

IPRD Other unsaturated aldehydes

MVK Unsaturated ketones

RNO3 Organic nitrates
Table 17 (continued)

63

 Name Description Amount in 

Base ROG [a]

Model species for explicitly represented product compounds that can also be emitted

HCHO Formaldehyde 8.3

CCHO Acetaldehyde 5.0

ACET Acetone 3.2

MEOH Methanol

HCOOH Formic acid

CCOOH Acetic acid

GLY Glyoxal

Model species for explicitly represented primary emitted VOCs.

CH4 Methane

ETHENE Ethene 14.1

ISOPRENE Isoprene 1.4

ACETYLEN Acetylene 10.2

BENZENE Benzene (also used for halo- and nitro-benzenes) 3.5

[a] Relative amount in the base ROG mixture used to represent emissions from all sources, in units of 

ppb model species per ppmC of mixture. This mixture was used to derive the parameters for the 

adjustable parameter lumped model species as discussed in this section, and was also used in the 

reactivity assessment calculations discussed in the "Updated Reactivity Scales" section, below.

The mechanisms for the model species already in the base mechanism have been discussed 

previously, and are given in Table A-2 in Appendix A. The mechanisms for the lumped species added to 

the base mechanism fixed parameter SAPRC-07 are derived using the same standard mixtures as used to 

derive their parameters for parameter SAPRC-99. For the model species ALKn, AROn, and OLEn, the 

mechanisms are derived based on the mixture of alkanes, aromatics, and alkenes in base reactive organic 

gas (ROG) mixture used to represent anthropogenic emissions from all sources used when calculating the 

Carter (1994) reactivity scales. This is based on an analysis by Jeffries et al. (1989) of urban ambient air 

measurements made by Lonneman (1986). For the model species TERP, the mechanisms are derived 

based on the top 5 terpenes in the North American Biogenic Inventory from the Guenther et al (2000) 

NARSTO assessment.

The mixtures of compounds used to derive the parameters for the adjustable parameter model 

species for the fixed parameter mechanism are given in Table 18 and Table 19, and Table A-7 in 

Appendix A gives the mechanisms that were so derived. The latter includes the reactions that were added 

to the standard base mechanism and also the reactions of these model species with chlorine atoms that are 

included when the mechanism is used to represent chlorine chemistry. These are based on the 

mechanisms for the individual components given in Table B-2 and Table B-7 in Appendix B, with the 

weighting factors shown in Table 18 and Table 19. Note that because of the difficulties in generating 

complete mechanisms for the Cl + alkene reactions (discussed above), the terpene + Cl mechanism is 

based entirely on that derived for -pinene, and, as indicated in Table B-7 the mechanisms and rate 

constants for many of the alkenes were assumed to be the same as structurally similar compounds.

Note that the mixtures used to derive the parameters for the model species in the fixed parameter 

mechanism may be out of date and need to be updated. An update to the base ROG mixture used to derive 
64

Table 18. Compounds and weighting factors used to derive the parameters for the ALK and ARO model species in the fixed parameter 

mechanism for airshed models

Group and Compound Mole 

Fract. Group and Compound Mole Fract. Group and Compound Mole Fract.

ALK1 ALK5 ARO2

Ethane 100% 2,4-Dimethyl Hexane 12% m-Xylene 13%

n-Decane 11% p-Xylene 13%

ALK2 3-Methyl Hexane 11% o-Xylene 11%

Propane 100% 2,3-Dimethyl Pentane 7% 1,2,3-Trimethyl Benzene 9%

2-Methyl Heptane 6% 1,3,5-Trimethyl Benzene 9%

ALK3 4-Methyl Heptane 6% 1,2,4-C10 trisubstituted benzenes 6%

n-Butane 68% 2,4-Dimethyl Heptane 5% m-Ethyl Toluene 5%

Isobutane 30% 2,6-Dimethyl Octane 5% o-Ethyl Toluene 5%

2,2-Dimethyl Butane 2% Methylcyclohexane 4% p-Ethyl Toluene 5%

n-Nonane 4% 1,2,4-Trimethyl Benzene 5%

ALK4 n-Octane 4% 1,2,3-C10 trisubstituted benzenes 4%

Isopentane 43% Cyclohexane 4% 1,3,5-C10 trisubstituted benzenes 2%

n-Pentane 17% 2-Methyl Nonane 3% m-C10 disubstituted benzenes 2%

2-Methyl Pentane 10% 2-Methyl Hexane 3% o-C10 disubstituted benzenes 2%

3-Methylpentane 7% 2-Methyl Octane 3% p-C10 disubstituted benzenes 2%

2,4-Dimethyl Pentane 5% 4-Methyl Octane 3% 1-methyl-4-isopropylbenzene 2%

Methylcyclopentane 5% n-Dodecane 2% m-C11 disubstituted benzenes 0.4%

n-Hexane 4% 4-Methyl Nonane 1.4% 1,3,5-C12 trisubstituted benzenes 0.3%

n-Heptane 3% Ethylcyclohexane 1.1% m-C12 disubstituted benzenes 0.2%

2,3-Dimethyl Butane 3% n-Undecane 1.0% p-C12 disubstituted benzenes 0.2%

Cyclopentane 2% 3,6-Dimethyl Decane 1.0% 1,2,4-C11 trisubstituted benzenes 0.2%

 1,1-dimethylcyclopentane 0.1% 2,6-Dimethyl Nonane 0.5% 1,2,3-C11 trisubstituted benzenes 0.2%

3-Methyl Undecane 0.5% 1,3,5-C11 trisubstituted benzenes 0.2%

ARO1 5-Methyl Undecane 0.5% 1,2,4-C12 trisubstituted benzenes 0.12%

Toluene 75% 3-Methyl Decane 0.2% 1,2,3-C12 trisubstituted benzenes 0.12%

Ethyl Benzene 10% 4-Methyl Decane 0.2% o-C11 disubstituted benzenes 0.10%

C11 Monosubstituted Benzenes 5% 1,2-dimethylcyclopentane 0.12% p-C11 disubstituted benzenes 0.10%

n-Propyl Benzene 4% Ethyl Cyclopentane 0.12% o-C12 disubstituted benzenes 0.06%

C10 Monosubstituted Benzenes 3% n-Tridecane 0.09%

Isopropyl Benzene (cumene) 2% 3,6-Dimethyl Undecane 0.03%

t-Butyl Benzene 0.7% 3-Methyl Dodecane 0.02%

 C12 Monosubstituted Benzenes 0.2% 5-Methyl Dodecane 0.02%
65

Table 19. Compounds and weighting factors used to derive the parameters for the OLE and TERP 

model species in the fixed parameter mechanism for airshed models

Group and Compound Mole 

Fraction

Group and Compound Mole 

Fraction]

OLE1 OLE2

Propene 29% cis-2-Pentene 14%

1-Hexene 24% trans-2-Pentene 14%

1-Butene 12% trans-2-Butene 11%

1-Pentene 11% Isobutene 10%

1-Heptene 11% cis-2-Butene 9%

1-Nonene 5% 2-Methyl-1-Butene 8%

3-Methyl-1-Butene 3% 1,3-Butadiene 6%

1-Octene 2% 2-Methyl-2-Butene 5%

1-Undecene 2% Cis-2-Hexene 5%

1-Decene 0.9% Trans-2-Hexene 5%

Trans-3-Heptene 4%

TERP Trans-4-Nonene 2%

-Pinene 38% [a] Trans-4-Octene 2%

-Pinene 27% Trans-5-Undecene 2%

3-Carene 17% Trans-2-Heptene 2%

Sabinene 10% Cyclohexene 2%

d-Limonene 9% Trans-4-Decene 0.7%

3,4-Diethyl-2-Hexene 0.2%

[a] The TERP + chlorine mechanism is assumed to be the same as that 

derived for -pinene.

the ALK, ARO, and OLE parameters is almost certainly called for given changes in anthropogenic 

emissions since the mid 80's, and advances in analytical methods. However, deriving updated base ROG 

mixtures is beyond the scope of this project, and the CARB and the EPA were unable to provide 

recommendations for an updated mixture within the time frame of this project. Therefore, the same 

mixture is retained in this update for consistency with SAPRC-99. However, the mechanisms for the 

individual compounds given in Table B-2 in Appendix B could be used as the basis for deriving updated 

mechanisms for these lumped model species once updated base ROG or terpene compositions become 

available.

Emissions Assignments

An important part of implementing mechanisms into airshed models involves assigning 

individual chemical compounds and categories used in speciation profiles to lumped species in the 

mechanism. The general types of compounds assigned to the various model species in the fixed parameter 

version of SAPRC-07 are indicated in Table 17, and the assignments of lumped model species to the 

individual compounds or types of compounds for which mechanistic assignments are made are shown in 

Table B-11 in Appendix B. For compounds or groups of compounds that are represented using the 

lumped molecule method as shown on Table B-9, the lumped model assignments are derived from those 

that are assigned to the explicitly represented compounds that are used to represent them.

Emissions speciation profiles use a variety of types of chemical categories, many of which do not 

refer to individual compounds or chemical categories used in the SAPRC mechanism. Because of this, we 

have previously developed an emissions speciation database for the purpose of assigning chemical 
66

categories used in emissions profiles to model species in various mechanisms in a consistent manner. The 

mechanisms currently supported in the database include CB4, CB05, RADM2, as well as SAPRC-99 

(Adelman et al, 2005; Carter, 2008b). This speciation database has been updated to support SAPRC-07 

and the files needed to process emissions for the fixed-parameter version of SAPRC-07 are available at 

the speciation database project web site (Carter, 2008b).

Note that emissions assignments are different than lumped molecule representations. Lumped 

molecule representations involve representing the compound or categories by a detailed model species, of 

which there are over 700, while emissions assignments involve representing id by one of the ~30 lumped 

model species used in airshed models. Obviously lumped molecule assignments are less approximate and 

should be used for purposes of reactivity scale calculations or deriving optimum mechanistic parameters 

for mixtures, where maximum chemical detail is appropriate. Emissions assignments such shown on 

Table B-11 and given in the speciation database (Carter, 2008b) should be reserved for applications where 

using the more limited number of lumped model species is necessary and appropriate.
67

MECHANISM EVALUATION

The performance of the mechanism in simulating O3 formation, rates of NO oxidation, and other 

measures of reactivity was evaluated by conducting model simulations of over 2500 environmental 

chamber experiments carried out in 11 different environmental chambers at 4 different laboratories1. The 

experiments included 682 single VOC experiments, consisting primarily of VOC - NOx or VOC - NOx

experiments with added CO or alkane, 591 incremental reactivity experiments, and 973 experiments with 

mixtures, though approximately 2/3 of the mixture runs were replicate base case reactivity experiments of 

various types. These include not only the experiments used when evaluating the SAPRC-99 mechanism 

(Carter, 2000a), but also the more recent experiments carried out at out at our laboratories at CE-CERT 

through June, 2006, experiments carried out in the Tennessee Valley Authority (TVA) chamber that were 

used in the low NOx mechanism evaluation study of Carter (2004), and also earlier University of North 

Carolina (UNC) chamber experiments used in the SAPRC-90 and RADM-2 mechanism evaluations of 

Carter and Lurmann (1990, 1991) and in the isoprene mechanism evaluation of Carter and Atkinson 

(1996). 

The chambers whose data were used for mechanism evaluation are summarized on Table 20, the 

types of experiments are summarized on Table 21, and the individual experiments are listed in Table C-1

in Appendix C. The input files, chamber data, and the computer programs used for the chamber 

simulations will be made available on the SAPRC mechanism web site2. The results of the evaluation are 

given on Table C-1 and in the numerous figures in Appendix C, and are summarized below.

Note that the largest database of environmental chamber experiments used for mechanism 

evaluation for this project is from indoor chamber experiments carried out at the University of California 

at Riverside (UCR). These experiments serve as the primary basis for mechanism evaluation and any 

adjustments made to mechanisms for individual VOCs are based on simulations of UCR indoor chamber 

runs. However, simulations of the available experiments from the Tennessee Valley Authority (TVA) 

chamber a subset of the experiments carried out in the University of North Carolina (UNC) outdoor 

chamber were also carried out, and results are also shown for information purposes. We believe that the 

TVA chamber is reasonably well characterized for modeling, and the results of these simulations provide 

useful supporting information for mechanism evaluation. However, because of time and resource 

constraints we were unable to obtain and process the most complete and quality-assured set of UNC 

chamber data. The generally poor performance of the model in simulating the non-isoprene UNC 

experiments may reflect this. For this reason, the simulations of the UNC chamber experiments are shown 

for information only, and were not used as the primary basis for mechanism evaluation. A re-evaluation 

using an improved UNC chamber dataset may be appropriate, but was beyond the scope of this project.

The performance of the mechanism is measured primarily in terms of its ability to simulate O3

formation and NO oxidation. The effect of the compounds on overall OH radicals in the incremental 

reactivity experiments is also assessed. Although the model simulations of the experiments also give 

information on the ability of the mechanism to predict other chemical transformations, such as rates of 

consumption of reactants other than NO and formation of various products besides O3 that may have been 

measured, a comprehensive mechanism evaluation in this regard was beyond the scope of this project. 

 

1 The experiments used to evaluate mechanisms for some of the compounds for which mechanisms and 

reactivity estimates are given were carried out after the experiment list for this report was finalized in 

March, 2009. In those cases, citations referencing the reports giving results of the evaluations for those 

compounds are given in footnotes to Table 23.

2 The SAPRC mechanism web site is at http://www.cert.ucr .edu/~carter/SAPRC.
68

Table 20. Summary of environmental chambers whose data were used for mechanism evaluation

ID Brief description and references for additional information

Chambers at the Statewide Air Pollution Research Center (SAPRC) or the College 

of Engineering Center for Environmental Research and Technology (CE-CERT) at 

the University of California at Riverside (UCR)

EC A 5774-liter evacuable chamber constructed of Teflon-coated aluminum with Quartz end 

windows. Located at SAPRC. Xenon arc solar simulator light source. Most experiments at ~50% 

RH and around 300oK. Experiments carried out 1975 - 1984. See Carter et al (1995a) for 

description of chamber and experimental methods and Carter (2000a) for a discussion of the 

modeling methods used. This chamber is now primarily being used for mechanistic studies.

ITC One semi-collapsible ~6400-liter reactor constructed of 2 mil FTP Teflon film held in a 

framework. Blacklight light source. Located at SAPRC. Most experiments at ~50% RH and 

around 300oK. Experiments carried out 1982 - 1986. See Carter et al (1995a) for description of 

chamber and experimental methods and Carter (2000a) for a discussion of the modeling methods 

used. This chamber is now primarily being used for mechanistic studies.

ETC One semi-collapsible ~3000-liter reactor constructed of 2 mil FTP Teflon film held in a 

framework. Blacklight light source. Located at SAPRC. Most experiments used dry air and 

carried out around 300oK. Experiments carried out 1989 - 1993. See Carter et al (1995a) for 

description of chamber and experimental methods and Carter (2000a) for a discussion of the 

modeling methods used. This chamber no longer exists.

OTC Two completely collapsible ~20,000-liter "pillow bag" reactors constructed of 2 mil FTP Teflon 

located outdoors. Located at the outdoor laboratory at SAPRC. Natural sunlight irradiation. Two 

irradiations carried out simultaneously, one in Side "A" and the other in Side "B". Experiments 

used dry air, with temperature varying with ambient conditions. Experiments carried out 1992 -

1993. See Carter et al (1995a,b) for description of chamber and experimental methods and Carter 

et al (1995b) and Carter (2000a) for a discussion of the modeling methods used. This chamber no 

longer exists.

DTC Two semi-collapsible ~5000-liter reactors constructed of 2 mil FTP Teflon film held in a 

framework. Initially located at the outdoor laboratory building at SAPRC, but subsequently reconstructed at CE-CERT. Two irradiations carried out simultaneously, one in Side "A" and the 

other in Side "B". Blacklight light source. Most experiments used dry air at around 300oK. 

Experiments carried out 1993 - 1999. See Carter et al (1995a) for description of chamber and 

experimental methods and Carter (2000a) for a discussion of the modeling methods used. This 

chamber no longer exists.

XTC One semi-collapsible ~5000-liter reactor constructed of 2 mil FTP Teflon film held in a 

framework. Xenon arc light source. Located the outdoor laboratory building at SAPRC. 

Experiments used dry air at around 300oK. Experiments carried out in 1993. See Carter et al 

(1995a) for description of chamber and experimental methods and Carter (2000a) for a discussion 

of the modeling methods used. This chamber no longer exists.

CTC 

(82)

Semi-collapsible ~5000-liter reactor constructed of 2 mil FTP Teflon film held in a framework. 

Xenon arc light source. Located at CE-CERT. Experiments used dry air at around 300oK. 

Experiments carried out in 1994 - 1995. See Carter et al (1995a) for description of chamber and 

experimental methods and Carter (2000a) for a discussion of the modeling methods used. This 

configuration is applicable to runs from 11 through 82.
Table 20 (continued)

69

ID Brief description and references for additional information

CTC 

(83)

Two semi-collapsible ~2500-liter reactors constructed of 2 mil FTP Teflon film held in a 

framework. Xenon arc light source. Located at CE-CERT. Experiments used dry air at around 

300oK. Experiments carried out in 1995 - 1999. This configuration is applicable to runs 83 and 

higher. See Carter et al (1995a) for description of chamber and experimental methods and Carter 

(2000a) for a discussion of the modeling methods used. This chamber no longer exists.

EPA (Also referred to as the UCR EPA chamber.) Two ~90% collapsible ~100,000-liter reactors 

constructed of 2 mil FEP Teflon film held on a framework with a moveable top for positive 

pressure control. Located in a temperature-controlled "clean room" clean room enclosure flushed 

with purified air. Located at CE-CERT. Can use either an argon arc solar simulator light source 

or blacklights. Two irradiations carried out simultaneously, one in Side "A" and the other in Side 

"B". Although the temperature and humidity can be varied, all experiments in this evaluation 

were carried out with dry air at around 300oK. Experiments carried out from 2003 through 

present, but latest run in this evaluation was carried out in mid-2006. See Carter (2004) and 

Carter et al (2005b) for a description of the chamber and experimental methods and Carter (2004) 

for a discussion of the modeling methods used. Note that mechanism evaluation experiments in 

this chamber can be carried out under lower NOx conditions than the other chambers at UCR or 

the UNC outdoor chamber. This chamber is still in operation.

Chamber at the Tennessee Valley Authority (TVA).

TVA One 28,300-liter reactor constructed of 0.13 mm FEP Teflon film on a rigid frame located inside 

an enclosure flushed with purified air. Special procedures used to clean between experiments to 

permit experiments at lower concentrations. Light source consisted of blacklights and sunlamps. 

Experiments carried out at about 15% RH and the temperature varied from ~300-315oK. 

Experiments carried out in 1993 - 1995. See Simonaitis and Bailey (1995) and Bailey et al 

(1996) for a description of the chamber and experimental methods and Carter (2004) for a 

discussion of the modeling methods used. Note that mechanism evaluation experiments in this 

chamber were carried out under lower NOx conditions than in the other chambers except for UCR 

EPA, but the chamber experience high background formaldehyde levels that needed to be taken 

into account when modeling the experiments (Carter, 2004). This chamber no longer exists.

Chamber at the University of North Carolina (UNC)

UNC A very large dual reactor chamber consisting of 5 mil FEP Teflon film held on a rigid A-frame 

structure located outdoors. Natural sunlight light source. Located in a rural site in North Carolina 

with filtered but otherwise unpurified air used for experiments that were conducted at ambient 

temperature. Two irradiations carried out simultaneously, one in side "R" and the other in side 

"B". Experiments are designated by their run date and side (e.g., JN1279R). Most of the 

experiments used in this evaluation were carried out between 1978 and 1985, but a few isoprene 

experiments were carried out in 1992 and 1993. See Jeffries et al (1982, 1985a,b) for descriptions 

of the chamber and experimental methods and Carter and Lurmann (1990, 1991) for a discussion 

of the modeling methods used for the earlier experiments and Carter and Atkinson (1996) for the 

isoprene experiments. Note that this may not be a complete dataset or contain the best qualityassured data from this chamber. This chamber has since been rebuilt and is probably not the 

primary chamber now used at UNC. 
70

Table 21. Summary of types of experiments used for mechanism evaluation.

Designation Mixture irradiated or description

Radical Source Characterization

CO - NOx CO - NOx

C4 - NOx n-Butane - NOx

NOx Offgasing characterization

CO - Air CO - Air

HCHO - CO - Air Formaldehyde - CO - Air

ACETALD - Air Acetaldehyde - Air

VOC Mechanism Evaluation

VOC - NOx VOC - NOx

VOC - CO - NOx VOC - NOx with added CO

VOC - C4 - Air VOC - air with added n-butane

VOC - C4 - NOx VOC - NOx with added n-butane

VOC - C2 - NOx VOC - NOx with added ethane

VOC - O3 VOC + O3 (also includes control experiment in the other reactor without the VOC)

IR Incremental reactivity experiment. Type of base case indicated

Standard surrogate - NOx experiments used in recent UCR experiments for mechanism evaluation

Surg-8 Standard 8-component "full surrogate" consisting of n-butane, n-octane, ethene, 

propene, trans-2-butene, toluene, m-xylene and formaldehyde (e.g., Carter et al, 

1995c; Carter, 2002)

Surg-7 Standard 8-component "full surrogate", above, but without formaldehyde (e.g. Carter 

and Malkina, 2005, 2007, Carter et al, 2005a)

Surg-3 Standard mini-surrogate consisting of ethene, n-hexane, and m-xylene (e.g., Carter et 

al, 1993, 1995c).

Surg-NA Standard 8-componene "full surrogate" but without aromatics and formaldehyde 

(unpublished results from this laboratory).

Surg-E Ethene surrogate consisting of ethene alone (e.g., Carter et al, 1995c).

Surg-x Miscellaneous 3- or 4-componene surrogates (e.g., Carter et al, 1993, Carter and 

Malkina, 2002)

Types of surrogate or incremental reactivity base case experiments

MIR1 Low ROG/NOx, MIR-like conditions. NOx 300-500 ppb (e.g., Carter et al, 1993, 

1995c)

MIR2 Low ROG/NOx, MIR-like conditions, NOx < 100 ppb (e.g., Carter, 2002; Carter and 

Malkina, 2005, 2007, Carter et al, 2005a)

LN1 Lower NOx, e.g., MOIR/2. NOx >100 ppb (e.g., Carter et al, 1993, 1995c)

LN2 Lower NOx,, e.g. MOIR/2 conditions, NOx < 50 ppb (e.g., Carter, 2002; Carter and 

Malkina, 2005, 2007, Carter et al, 2005a)

vary Non-standard ROG/NOx. Conditions varied

Older UCR and UNC and TVA surrogate and mixture - NOx experiments

ITCsrg-4 Experiments in the ITC chamber (primarily) using a 4-component surrogate, 

primarily for the early incremental reactivity study of Carter and Atkinson (1987). 

Surrogate consisted of propene, n-butane, trans-2-butene, and m-xylene.

ITCsrg-4R Based on ITCsrg-4, but with propene removed. Used in the study of Carter and 

Atkinson (1987).
Table 21 (continued)

71

Designation Mixture irradiated or description

ECsrg-7 A surrogate mixture of seven hydrocarbons used in several runs in the SAPRC EC 

(Pitts et al, 1979). Consisted of n-butane, 2,3-dimethyl butane, ethene, propene, trans2-butene, toluene, m-xylene

MDsrg-8 A surrogate mixture of 8 hydrocarbons used in the "multi-day effects" study of Carter 

et al (1984). Consisted of n-butane, n-pentane, isooctane, ethene, propene, isobutene, 

toluene, and m-xylene

TVAsrg-1 A complex surrogate mixture of alkanes, alkenes, and aromatics used in the TVA 

chamber (Simonaitis and Bailey, 1995; Bailey et al, 1996).

TVAsrg-2 A complex surrogate mixture of alkanes, alkenes, and aromatics used in the TVA 

chamber (Simonaitis and Bailey, 1995; Bailey et al, 1996).

UNCsrg-3 A simple surrogate of propene, n-butane and an aromatic used in the UNC chamber 

(Jeffries et al, 1982, 1985a).

SynUrb A complex "synthetic urban" VOC mixture used in the UNC chamber (Jeffries et al, 

1985a)

SynAuto A synthetic auto exhaust VOC mixture used in the UNC chamber (Jeffries et al, 

1985b)

UNCsrg-x Miscellaneous surrogates used in the UNC chamber (Jeffries et al, 1982, 1985a).

Simple mixtures (incomplete surrogates)

Mix-A Mixture of alkanes

Mix-E Mixture of alkenes

Mix-AE Mixture of alkanes and alkenes

Mix-AO Mixtures of alkanes and oxygenates (generally aldehydes)

Mix-EO Mixture of alkenes and oxygenates

Mix-RO Mixtures of aromatics and oxygenates (generally aldehydes) 

Mix-AR Mixtures of alkanes and aromatics

Mix-ER Mixtures of alkenes and aromatics

Light Source Designations used in run listing

A Arc light (Xenon or Argon arc) solar simulator

Bl Blacklights

Bs Mixture of blacklights and sunlamps

S Solar light

This would be a major effort because of the considerable amount of variation from experiment to 

experiment in terms of measurements of other species that were made, and the highly variable and 

uncertain quality of much of the measurements (e.g., see Carter et al, 1995a for a discussion of the 

measurement data for the earlier UCR chamber experiments). However, evaluations of model 

performance in simulating individual oxidation products was often used when developing mechanisms for 

individual VOCs when relevant data were available, and in general the mechanisms for these compounds 

retain the product yield predictions so developed when updated for this version.

Methods

The procedures used when evaluating the mechanism against the chamber data were the same as 

employed in previous evaluations of the SAPRC-90 (Carter and Lurmann, 1990, 1991) and SAPRC-99 

(Carter, 2000a, 2004; Carter and Malkina, 2007) mechanisms. Briefly, evaluations of mechanisms using
72

chamber data require an appropriate representation of the conditions of the chamber experiments that 

affect the simulation results. These include initial reactant concentrations, physical conditions such as 

temperature and dilution, light intensity and spectrum, and the major wall effects such as the chamber 

radical source, O3 decays, NOx offgasing, etc. These considerations are discussed in detail elsewhere (e.g., 

Carter et al, 1982; Carter and Lurmann, 1990, 1991; Carter et al, 1995a,b, 1997a; Carter, 2000a and 

references therein), and that discussion will not be duplicated here.

The parameters in the chamber effects model used when modeling the experiments for this 

mechanism evaluation are given in Table 22. Except for the parameters used to model the chamberdependent radical source and NOx offgasing, which have to be adjusted for each mechanism, the input 

data used in modeling the chamber experiments were the same as used in previous studies. The reports 

describing the methods used to derive the input data, and giving the chamber effects characterization 

parameters employed, are given in footnotes to Table 20. As indicated above, the input data files will be 

made available at the SAPRC mechanism web site.

The most important and variable chamber background effect is the "chamber radical source" first 

noted by Carter et al (1982) and background NOx offgasing. The former causes enhanced NO oxidation 

and O3 formation experiments, such as CO - NOx or alkane - NOx irradiations with no significant radical 

sources in the gas-phase mechanism, while the latter causes O3 formation in experiments where NOx has 

not been added. Both of these effects are attributed to offgasing of HONO, which have been observed 

experimentally in the SAPHIR outdoor chamber in Germany (Brauers et al, 2003, Rohrer et al, 2004) to 

occur at rates similar to the radial source and NOx offgasing rates derived for the UCR EPA chamber 

(Carter et al, 2005b). The magnitudes of the radical source and NOx offgasing effects are larger in the 

older chambers (Carter and Lurmann, 1990, 1991; Carter et al, 1995a, 2005b; Carter, 2000a), but they are 

still generally comparable to each other, consistent with the assumption that both are due to the same 

process. This is represented in the chamber model by the parameter RN, which is the rate of HONO 

offgasing relative to the light intensity as measured by the NO2 photolysis rate.

Since HONO has not been measured directly in any of the chambers used for mechanism 

evaluation for the conditions relevant to the experiments, the HONO offgasing rate parameter has to be

determined by adjusting the parameter so the model calculations can simulate results of the appropriate 

characterization experiments. The most sensitive experiments are the CO - NOx and alkane (primarily nbutane) - NOx experiments used for radical source characterization, and modeling these experiments is the 

primary method used to derive the RN parameters used when modeling the mechanism evaluation runs. 

The best fit parameters depend to some extent on the chemical mechanism used, particularly the rate 

constant for the OH + NO2 reaction, which is the main radical terminating reaction in the characterization 

experiments. Since this rate constant changed in SAPRC-07 compared to SAPRC-99, the set of RN 

parameters used in the mechanism evaluation also changed.

The RN parameters that were used when modeling the chamber experiments for this mechanism 

evaluation are given on Table 22. They were derived to minimize biases in simulations of the radical 

source characterization experiments, as indicated on Table 21 and Table C-1 in Appendix C. For this 

purpose, experiments were grouped into "characterization sets" that were assumed to have similar 

chamber effects parameters. As discussed by Carter et al (1995a) and Carter (2002), for some chambers 

the conditions affecting radical sources and NOx offgasing appeared to change from time to time due to 

changes in reactors, exposure to reactants, etc., and assignments to characterization sets are used to take 

this into account. The characterization sets associated with the individual experiments are included with 

the run listing in Table C-1.
73

Table 22. Chamber wall effect and background characterization parameters used in the 

environmental chamber model simulations for mechanism evaluation. 

Cham. Set(s) Value Discussion

RN-I (ppb) Ratio of the rate of wall + h -> HONO to the NO2 photolysis rate.

EPA 2 0.0075 Average of values that gave best fits to n-butane - NOx and CO - NOx, 

radical source characterization and CO - air NOx offgasing characterization 

experiments carried out in this chamber. Note that for Set 3 the best fit 

RN-I values depended on the reactor.

3A 0.0165

3B 0.0115

4 0.0055

5 0.0110

6 0.0150

7 0.0100

ITC All 0.0475 Average of value of RS-I that gave best fits to n-butane - NOx radical 

source characterization chamber experiments carried out in this chamber.

ETC 2-3 0.04 Same procedure as above

DTC 1 0.058 Same procedure as above

3 0.210

4 0.300

10 0.055

11 0.092

12 0.310

13 0.170

14 0.095

15 0.063

16 0.240

17 0.083

18 0.074

XTC All 0.085 Same procedure as above

CTC 1 0.06 Same procedure as above

2,3 0.10

4-8 0.095

9 0.115

10 0.08

OTC 7.2e+9 exp(-9712/T) 

0.063 @ 300K

Based on Arrhenius plots of values of RS-I that give fits to n-butane - NOx

chamber experiments carried out in this chamber for the average 

temperatures of the experiments.

EC 1 0.235 Based on the NO2 dependence radical source derived by Carter et al 

(1982), adjusted to reduce biases in simulations of n-butane - NOx

experiments carried out in this chamber using this mechanism. The NO2-

dependent radical source term, RS-S, was reduced by an equal factor.

TVA All 0.008 Estimated value. Could not be determined by modeling radical source 

characterization because of the large formaldehyde offgasing. See Carter 

(2004).

UNC All 4.0e+14 exp(-12581/T) 

0.248 @ 300K

Based on Arrhenius plots of values of RS-I that give fits to the few 

available alkane - NOx chamber experiments carried out in this chamber 

for the average temperatures of the experiments. Older experiments 

modeled by Carter and Lurmann (1990, 1991) were used.

RS-S (unitless) Ratio of the rate of NO2 + hv -> 0.5 HONO + 0.5 wall NOx to the NO2

photolysis rate.
Table 22 (continued)

74

Cham. Set(s) Value Discussion

EC 1 0.0017 Based on the NO2 dependence radical source derived by Carter et al 

(1982), adjusted downward by 20% to reduce biases in simulations of nbutane - NOx experiments carried out in this chamber. The NO2-

independent radical source term, RN-I, was reduced by an equal factor.

All others 0 Any dependence of apparent radical source on initial NOx levels in Teflon 

bag chambers was found to be much less than the run-to-run variability.

HONO-I (ppb) Initial HONO in experiment, assumed to be independent of other reactants 

unless indicated.

EPA All 0.05 Value that usually gives best fits to model simulations of results of nbutane - NOx and CO - NOx experiments in this chamber. 

ITC All 1.7 Average of initial HONO value that gave best fits to n-butane - NOx

chamber experiments carried out in this chamber. The RN-I parameter was 

optimized at the same time. The best fit initial HONO values appear to be 

approximately independent of the initial NO2.

ITC All 1.7 Similar procedure as above.

TVA All 0.5 Similar procedure as above.

DTC 1 0.001 x [NO2]init Similar procedure as above, except for this chamber the best fit initial 

3,4 0.004 x [NO2]init HONO appeared to be correlated with the initial NO2 concentrations. 

10,18 0.008 x [NO2]init

11,14 0.006 x [NO2]init

12,16 0.005 x [NO2]init

13 0.009 x [NO2]init

15 0.007 x [NO2]init

17 0.003 x [NO2]init

XTC All 0.012 x [NO2]init Similar procedure as above

CTC All 0.008 x [NO2]init Similar procedure as above

EC All 0.07 x [NO2]init Similar procedure as above

ETC, OTC, 

UNC

0 For most (though not all) characterization runs in these chambers the data 

are simulated best if the effect of any initial HONO is small compared to 

other chamber radical sources, o

E-NO2/K1 (ppb) Ratio of rate of NO2 offgasing from the walls to the NO2 photolysis rate.

EC 1 0.10 Adjusted to fit O3 formation in acetaldehyde/air run EC-253.

All Teflon 

Film Chambers

0 The NOx offgasing caused by representing the radical source by HONO 

offgasing appears to be sufficient for accounting for NOx offgasing effects 

in most cases. RN-I parameters adjusted to fit experiments sensitive to the 

radical source are consistent with NOx offgasing rates adjusted to fit pure 

air or aldehyde - air runs, to within the uncertainty and variability.

K(NO2W) (min-1) Rate of unimolecular loss (or hydrolysis) of NO2 to the walls.

All Teflon 

Film Chambers

1.6e-4 Based on dark NO2 decay and HONO formation measured in the ETC by 

Pitts et al. (1984). Assumed to be the same in all Teflon bag chambers, 

regardless of volume.

EC 1 2.8e-4 Based on dark NO2 decay and HONO formation measured in the EC by 

Pitts et al. (1984).

UNC All 5.0e-5 Value used by Carter and Lurmann (1990, 1991) was not updated.
Table 22 (continued)

75

Cham. Set(s) Value Discussion

YHONO Yield of HONO in the unimolecular reaction (hydrolysis) of NO2 on the 

walls.

All Teflon 

Film Chambers

0.2 Based on dark NO2 decay and HONO formation measured in the ETC by 

Pitts et al. (1984). Assumed to be the same in all Teflon bag chambers, 

regardless of volume.

EC 1 0.5 Based on dark NO2 decay and HONO formation measured in the EC by 

Pitts et al. (1984).

E-ALD/K1 (ppb) Ratio of rate of formaldehyde offgasing from the walls to the NO2

photolysis rate.

EPA All 0.01 Gives best fits to formaldehyde data in most pure air irradiations and other 

experiments where formaldehyde should not otherwise be present.

TVA 0.045 + other sources 

(see discussion)

This chamber had significant wall offgasing of formaldehyde and 

assuming a constant offgasing rate did not give best fits to the data. The 

additional process required to fit the data, derived by Simonaitis et al 

(1997) and used by Carter (2004), are as follows:

Walls + h  WALLVOC; rate = NO2 photolysis rate x 0.135 ppb

WALLVOC + OH  HO2 + 0.2 HCHO; k = 2 x 104ppm-1 min-1

All other 

chambers

0 Simulations of characterization experiments do not require assuming 

formaldehyde offgasing. Formaldehyde measurements not sufficiently 

sensitive to determine formaldehyde offgasing.

K(O3W) (min-1) Unimolecular loss rate of O3 to the walls.

EPA All 1.08e-4 Based on results of O3 decays carried out in this chamber

ITC, ETC, 

DTC, XTC

1.5e-4 Based on results of O3 decay in Teflon bag chambers experiments as 

discussed by Carter et al (1995a).

CTC All 8.5e-5 Based on results of O3 decay experiments in this chamber

OTC All 1.67e-4 Similar procedure as above

EC All 1.1e-3 Similar procedure as above

TVA All 7.0e-4 Similar procedure as above

UNC All 1.43e-4 Similar procedure as above

k(N26I) (min-1) Rate constant for N2O5 -> 2 Wall-NOx. This represents the humidityindependent portion of the wall loss of N2O5, or the intercept of plots of 

rates of N2O5 loss against humidity.

All Teflon Bag 

Chambers

2.8e-3 Based on N2O5 decay rate measurements made by Tuazon et al (1983) for 

the ETC. Assumed to be independent of chamber size (Carter et al, 1995a).

EC 1 4.7e-3 Based on N2O5 decay rate measurements made by Tuazon et al (1983) for 

the EC. See also Carter et al (1995a).

k(N26S) (ppm-1 min-1) Rate constant for N2O5 + H2O -> 2 Wall-NOx. This represents the 

humidity dependent portion of the wall loss of N2O5, or the slope of plots 

of rates of N2O5 loss against humidity. Note that this is in addition to the 

N2O5 hydrolysis reaction in the gas-phase mechanism.

All Teflon Bag 

Chambers

1.1e-6 Based on N2O5 decay rate measurements made by Tuazon et al (1983) for 

the ETC. Assumed to be independent of chamber size (Carter et al, 1995a).

EC 1 1.8e-6 Based on N2O5 decay rate measurements made by Tuazon et al (1983) for 

the EC. See also Carter et al (1995a).
Table 22 (continued)

76

Cham. Set(s) Value Discussion

EPA All 0 Assumed to be negligible compared to the homogeneous process already 

in the base mechanism

UNC All 2.0e-8 Value used by Carter and Lurmann (1990, 1991) was not updated.

k(XSHC) (min-1) Rate constant for OH -> HO2. This represents the effects of reaction of 

OH with reactive VOCs in the background air or offgassed from the 

chamber walls. This parameter does not significantly affect model 

simulations of experiments other than pure air runs.

All Teflon Bag 

Chambers

250 Estimated from modeling several pure air in the ITC (Carter et al, 1996d), 

and also consistent with simulations of pure air runs in the ETC (Carter et 

al, 1997a).

EC 1 0 Assumed to be negligible because the EC is generally evacuated overnight 

between experiments (Carter et al, 1995a).

EPA, TVA 0 Assumed to be negligible because steps are taken to reduce background 

effects for low concentration experiments.

UNC 750 Value used by Carter and Lurmann (1990, 1991) was not updated.

H2O (ppm) Default water vapor concentration for runs where no humidity data are 

available.

EPA All 3.4e+2 The EPA chamber experiments used for mechanism evaluation to date 

were not humidified. This is the expected upper limit water concentration.

ITC All 2.0e+4 This corresponds to ~50% RH at 303K, which is the condition for most 

experiments in this chamber.

DTC 4 2.0e+4 This corresponds to ~50% RH at 303K, which is the condition for 

experiments in this characterization set. (The other DTC experiments are 

not humidified)

EC 1 2.0e+4 This corresponds to ~50% RH at 303K, which is the condition for most 

experiments in this chamber. Humidity data are available for most EC 

runs, so the default is usually not used.

TVA, UNC (no default) The water concentration is specified in the input files for all experiments.

All Other 

Chambers or 

char. sets.

1.0e+3 Experiments in these chambers were carried out using dried purified air. 

The limited humidity data for such runs indicate that the humidity was less 

than 5%, probably no more than ~2.5%, and possibly much less than that. 

The default value corresponds to ~2.5 - 3% RH for the conditions of most 

experiments.

Dilution rate (min-1) Default rate of dilution in the experiment (used for most experiments if no 

dilution specified for the experiment)

EPA All 0 Dilution expected to be small because of the design of the chamber

ITC All 0 Dilution not well characterized but assumed to be small.

ETC All 8.0e-5 Based on CO dark decays or other dilution characterization data.

DTC 1 5.3e-5 Similar procedure as above

3,4 1.8e-4

10-18 5.3e-5

XTC All 2.7e-5

Similar procedure as above

CTC All 6.7e-5

Similar procedure as above

OTC All 6.7e-5

Similar procedure as above

EC All 2.0e-4

Similar procedure as above
Table 22 (continued)

77

Cham. Set(s) Value Discussion

TVA (no default) Dilution specified in input files for each experiment

UNC All 2.0e-4 Value used by Carter and Lurmann (1990, 1991) was not updated.

Note that, as discussed by Carter (2002) and Carter et al (2005b), the UCR EPA and the TVA 

chambers have much lower apparent NOx offgasing rates than the older chambers, because these 

chambers were designed for conducting experiments at lower pollutant concentrations. Runs in these 

chambers were generally carried out at lower pollutant levels than in the other chambers, and the 

concentrations are generally more representative of ambient conditions. However, the TVA chamber had 

very high background levels of formaldehyde (Carter, 2002), so of these two chambers the UCR EPA 

chamber has the lowest overall background effects.

Although most of the mechanism evaluation is based on simulations of environmental chamber 

experiments, we will also present results of simulations of the "direct reactivity" experiments developed 

by Carter and Malkina (2002). These consist of plug flow experiments where the effect of adding the 

VOC to HONO - air irradiations is determined. In the absence of added VOCs, the HONO - air plug flow 

irradiations results in the formation of NO, which is measured. If a VOC is added to the mixture, the OH 

radicals formed in the photolysis of HONO become peroxy radicals that convert the NO to NO2, and, if 

the amount of added VOC is sufficient to consume all the NO, causes O3 to be formed. The change in NO 

consumption and O3 formation, relative to the no-VOC case, for the limit of zero added VOC is the 

measure of direct reactivity that is used. Model calculations carried out by Carter and Malkina (2002) 

show that this measurement is sensitive to the rate constant for the reactions of the VOC and the number 

of NO to NO2 conversions caused when it reacts, but is not sensitive to indirect reactivity effects such as 

effects of VOCs on radical or NOx levels. They showed that the results were generally consistent with the 

predictions of the SAPRC-99 mechanism except for benzene and toluene, where the direct reactivities 

were significantly overpredicted.

The methods used to simulate the direct reactivity experiments for this evaluation were the same 

as described by Carter and Malkina (2002) for SAPRC-99.

Data Presented

The results of the model simulations of the various types of experiments are given primarily in 

various plots and tables in Appendix C, and a few representative results are presented in conjunction with 

the discussion below. In most cases, results are given for SAPRC-99 as well as this version of the 

mechanism, so the changes caused by the mechanism update can be assessed. As indicated above, the 

performance of the mechanism is measured primarily in terms of its ability to simulate O3 formation and 

NO oxidation, though the effect of the compounds on overall OH radicals in the incremental reactivity 

experiments is also assessed. 

The amount of O3 formed and NO oxidized in the experiments is measured by the quantity

([O3]-[NO]), which is calculated by [O3]t - [NO]t - ([O3]0 - [NO]0), where [O3]0, [NO]0, [O3]t, and [NO]t

are the initial and time=t concentrations of ozone, and NO, respectively. As discussed previously (e.g., 

Carter and Atkinson, 1987; Carter and Lurmann, 1990, 1991), this gives a measure of the ability of the 

model to simulate the chemical processes that cause ozone formation that gives a useful measure even 

where ozone is suppressed by the presence of excess NO. The ability of the mechanism to simulate this 

quantity in the experiments is measured by its "model error", which is calculated as 

([O3]-[NO]) model error = {([O3]-[NO])model - ([O3]-[NO])experimental} / ([O3]-[NO])experimental.
78

These values are calculated for each hour of the experiments, with the experimental values being derived 

by linear interpolation if no measurement were made exactly on the hour. Table C-1 in Appendix C gives 

the model errors for the second hour and the sixth hour (or final hour if the experiment was less than 6 

hours) for all the experiments, and distributions of these values are shown for various types of 

experiments as discussed below. 

Because of the very large number of VOC - NOx and mixture - NOx experiments used in the 

evaluation, in most cases experimental and calculated concentration time plots are not shown for 

individual experiments, and only distributions of model errors are presented. The model error results for 

the different types of experiments are shown in various figures in Table C-1 and in the discussion of the 

results below. These figures show how the average model errors vary with time during the experiments, 

which give information on the model performance in terms of simulating rates of NO oxidation and O3

formation, as well as simulating final O3 yields. These figures also show distribution plots of model errors 

for hour 2 and final ([O3]-[NO]). These show the degree of run-to-run variability of model performance 

in simulating these quantities. Results for comparable types of experiments are shown together, but 

because of the large number of types of experiments, a relatively large number of plots is needed.

As indicated in Table 20, a large number of mechanism evaluation experiments consisted of 

incremental reactivity experiments, and a different method was used to present the results for these 

experiments. Incremental reactivity experiments consist of simultaneous (or alternating) irradiations of a 

"base case" reactive organic gas (ROG) - NOx mixture providing a simplified model of ambient chemical 

conditions, and irradiations of the same mixture with a test compound or mixture added. In this case the 

measures of model performance of interest concern the ability of the mechanism to predict the effects of 

the compound on the experiment. However, it is also important to see how well the model simulates the 

base case experiment as well, because if it performs poorly it may introduce errors in the simulations of 

the effects of adding the test compound if the chemical conditions influencing these effects are not 

correctly simulated.

Because of the relatively limited number of incremental reactivity experiments for any given 

compound combined with the additional considerations involved in assessing model performance for such 

experiments, the presentation of the evaluation results for the incremental reactivity experiments in 

Appendix C give plots for each experiment. These include experimental and calculated time plots of 

([O3]-[NO])Base, ([O3]-[NO])Test, and IR ([O3]-[NO]), where ([O3]-[NO])Base and ([O3]-[NO])Test are 

the ([O3]-[NO]) in the base case and the added test VOC experiments, respectively, and 

IR ([O3]-[NO]) = {([O3]-[NO])Test - ([O3]-[NO])Base} / amount of test VOC added

where ([O3]-[NO])Base and ([O3]-[NO])Test are the ([O3]-[NO]) in the base case and the added test 

VOC experiments, respectively. The IR ([O3]-[NO]) values are given in molar units (e.g., ppm 

([O3]-[NO]) / ppm VOC added) if the test VOC is a single compound, or in mole carbon units if the test 

VOC is a complex mixture such as a petroleum distillate. Each figure includes plots for experiments with 

a single compound or group of similar compounds.

Note that in the incremental reactivity experiments carried out in the ETC, the base case 

experiments were not carried out at the same time as the added test VOC experiments, but were carried 

out separately. This is because this is a single reactor chamber that does not permit simultaneous 

injections and irradiations of common reactants. For those experiments, the base case results for a given 

added test VOC experiment were interpolated or derived using correlations between initial reactant 

concentrations and other characterization results in the base case experiment. Therefore, in the plots of the 

([O3]-[NO]) data, the figures only show the model calculations for the base case experiment, not the 

experimental data.

The figures with the evaluation results for the incremental reactivity experiments also show plots 

of the experimental and calculated effects of the VOC on the integrated OH radical levels. This is useful 
79

for mechanism evaluation because an important factor affecting a VOC's incremental reactivity is its 

effect on overall radical levels, which affects O3 formation caused by the reactions of other VOCs that are 

present. For radical inhibiting VOCs such as higher alkanes, the reduced O3 formation caused by the 

effect of the VOCs on the reactions of the other compounds present counter-acts the direct O3 formation 

caused by the compound's own reactions, resulting in a low net incremental reactivity for ([O3]-[NO]). 

However, for such compounds the effects on integrated OH levels, or IntOH are quite large, indicating

that the compound indeed is having a large effect on the chemistry of the system.

The IntOH levels in the experiments are calculated from the rates of consumption of the most 

reactive VOC in the base case mixture that reacts only with OH radicals (usually m-xylene but sometimes 

n-octane or 1,3,5-trimethylbenzene) (Carter et al, 1993). The effect of the test VOC on this quantity is 

measured by

IR IntOH = {IntOHTest - InOHBase} / amount of test VOC added

where IntOHBase and IntOHTest are the IntOH values derived from the base case and the added test VOC 

experiments, respectively. They are given in units of ppt-minute per ppm of test VOC added if the test 

VOC is a compound, or ppt-minute per ppmC of test VOC if it is a complex mixture.

Results

Results for Chamber Characterization Experiments

The results of the simulations of the radical source and NOx offgasing characterization 

experiments are shown on Figure 5 and Figure 6, respectively. These show distribution of model errors 

for both the SAPRC-99 and SAPRC-07 mechanisms as described above. It can be seen that there is 

relatively large variation from run to run, indicating the variability of the chamber effects related to 

radical source and NOx offgasing. The average biases for the radical source characterization runs are 

generally small being within 25%, as would be expected since the radical source parameters were 

adjusted to minimize the biases. Except for the single CTC experiment, the biases for the NOx offgasing

characterization runs are also not large compared to the variability, despite the fact that, except for the 

TVA chamber where the large formaldehyde offgasing makes runs insensitive to the chamber radical 

source, the NOx offgasing parameters were adjusted based on the radical source characterization runs. 

This is consistent with the expectation that they are both due to the same effect.

From the perspective of mechanism evaluation it is important to realize that these radical source 

and NOx offgasing characterization experiments are, by design, particularly sensitive to these variable 

chamber effects. The experiments used for mechanisms evaluation, discussed in the following section, are 

much less sensitive to these effects, and variabilities in radical source or NOx offgasing should not be 

important sources of variability in the simulations of these experiments. However, it is important that 

these chamber effects not be a source of bias in the simulations of the mechanism evaluation runs, so it is 

important that appropriate values of the parameters representing these effects be used. 

Results for Mechanism Evaluation Experiments

The performance of the SAPRC-07 mechanism in simulating NO oxidation and O3 formation in 

the mechanism evaluation experiments is given in Table C-1 and in the various figures in Appendix C. 

The ability of the mechanism to simulate effects of the added test compounds on integrated OH levels in 

the incremental reactivity experiments is also shown in the figures for those experiments. For comparison 

purposes, results for SAPRC-99 are also shown on the figures, except for those few compounds that are 

not represented in SAPRC-99. The results for various types of experiments are summarized below.

Overall Performance in Simulating Entire Dataset

Figure 7 shows the distributions and averages of model errors in the SAPRC-07 and 

SAPRC-99 simulations of NO oxidized and O3 formation in the entire set of mechanism evaluation 
80

chamber experiments modeled for this project. It can be seen that both mechanisms have essentially no 

bias in simulating ([O3]-[NO]) after the first hour of the experiment, though they both tend to slightly 

overpredict NO oxidation rates in the first hour. The same is true for the SAPRC-99 simulations of the 

mixture experiments. On the other hand, the updated mechanism has a small positive average bias in 

simulating the mixture experiments, averaging about 20% for the first hour (only slightly greater than that 

for SAPRC-99), going down to about 6% by the end of the run. However, this bias is small compared to 

the overall variability of the fits, which are within 30% for most experiments for both mechanisms. 

Therefore, this slight positive bias for the updated mechanism in simulating the mixture runs may not be 

significant.

The reason for the slight positive bias in the simulations of ([O3]-[NO]) in the mixture 

runs, if significant, is uncertain. The results for the single compounds or individual mixtures do not 

clearly indicate a cause in terms of particular compounds or types of compounds. It is considered unlikely

that the slightly increased positive bias is due to problems with chamber characterization, since the most 

important chamber characterization parameters, regarding radical sources and NOx offgasing, were readjusted for this version of the mechanism, and the other parameters were the same as used for SAPRC99. 

Indeed, if anything, Figure 5 and Figure 6 suggest that the parameters used with updated 

mechanism may be slightly biased towards being too unreactive in this regard. Of the rate constant 

updates made to the base mechanism, potentially the most important is the increase in the OH + NO2

reaction, which is a major radical termination process that is important in essentially all experiments. But 

the increase, by itself, should cause slower NO oxidation and O3 formation, which is opposite of the 

direction seen. On the other hand, if parameters in the mechanisms for the individual VOCs are adjusted 

to compensate for this change, it might cause increased reactivity in simulations of experiments that are 

more sensitive to these parameters than the OH + NO2 rate constant. As indicated below, some uncertain 

mechanistic parameters (primarily nitrate yields in peroxy + NO reactions or yields of photoreactive 

aromatic products) had to be re-adjusted for the updated mechanism to fit results of reactivity and single 

VOC - NOx experiments. This may need to be investigated.

Evaluation Experiments for Individual VOCs

The major mechanism evaluation dataset consisted of the >1200 experiments carried out 

to evaluate mechanisms of almost 130 individual compounds and mixtures. These compounds or mixtures 

are listed on Table 23, along with an indication of the number and types of experiments for each, and 

references to the figure or figures in Appendix C where the results of the evaluation are presented. Table 

23 also indicates whether any uncertain parameters were adjusted in the mechanisms as a result of this 

evaluation, and gives codes and comments concerning the overall quality of the fits, which are described 
81

Figure 5. Distribution of ([O3]-[NO]) model errors for the radical source characterization 

experiments.

Radical Source Characterization Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

EPA 48 6% 4% 5% 7%

Indoor TC [a] 141 1% 0% -8% -3%

EC 7 9% 21% -19% -3%

TVA 8 -20% -5% -21% -16%

OTC 6 -6% -6% -8% -8%

UNC 6 -1% 20% -14% 17%

[a] ITC, ETC, DTC, XTC, and CTC

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Chamber Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

UCR EPA

Indoor TC

EC

TVA

OTC

UNC

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
82

Figure 6. Distribution of O3 model errors for the NOx offgasing characterization experiments 

NOx Offgasing Characterization Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

UCR EPA 36 -17% -5% -13% 20%

CTC 1 -11% 54% -19% 36%

ITC 3 -31% -28% -33% -30%

TVA 2 -6% 9% -10% 10%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Chamber Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

UCR EPA

CTC

ITC

TVA

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
83

Figure 7. Distributions of ([O3]-[NO]) model errors for all of the single VOC - NOx and mixture -

NOx experiments used in the mechanism evaluation.

All Experiments

Group Runs Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Avg Sdev Avg Sdev Avg Sdev Avg Sdev

Single VOC 682 3% 34% 2% 19% 0% 34% 0% 26%

Mixtures 1559 4% 32% 2% 20% 10% 40% 5% 23%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

-20%

-10%

0%

10%

20%

1 2 3 4 5 6

-20%

-10%

0%

10%

20%

1 2 3 4 5 6

Single VOC

Mixtures

0%

10%

20%

30%

40%

50%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

10%

20%

30%

40%

50%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

10%

20%

30%

40%

50%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

10%

20%

30%

40%

50%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
84

Table 23. Summary of mechanism evaluation results using chamber experiments for individual 

compounds and mixtures.

Compound or Mixture No. Runs [a] Fig. No. [b] O3-NO Fits [c] Adj [d] Note [e] Single Rct'y Single Rct'y Rate Max

Single Compounds (or simple isomeric mixtures)

Carbon monoxide 13 1 ok ok

Ethane 7 2 ok ok

Propane 3 2 ok

N-Butane 10 3 ok ok

N-Hexane 3 4 ok ok

N-Octane 13 5 ok ok

N-Dodecane 9 6 ok +1

N-Tetradecane 8 7 ok +1

N-Pentadecane 2 8 ok +1

N-C16 5 8 ok +1

Isobutane 4 9 ok

2,2,4-Trimethyl pentane 2 9 ok 1

2,6-Dimethyl octane 5 9 ok ok

2-Methyl nonane 5 10 ok +1

3,4-Diethyl hexane 6 10 ok +1

Cyclohexane 6 11 ok ok

Hexyl cyclohexane 6 11 ok ok

Octyl cyclohexane 7 12 ok ok

Ethene 49 4 13 14 ok ok Or

Propene 190 10 15 16 ok ok Or

1-Butene 6 17 ok ok Or

1-Hexene 3 17 -2 -2 Or

Isobutene 2 3 18 19 ok

Trans-2-butene 6 9 18 19 ok ok

Isoprene 28 10 20 21 ok ok

3-carene 4 22 -1 -1

-Pinene 6 4 22 23 ok ok Or, yN

-Pinene 6 2 22 23 ok note Or, yN 2

d-Limonene 7 3 [f] 22 23 ok ok

Sabinene 3 22 ok ok

Cyclohexene 1 24 ok ok

Styrene 6 25 ok ok

Benzene 9 4 25 27 note ok yP 3,4

Toluene 60 6 28 30 note ok yP 4,5,6

Ethyl benzene 8 3 29 30 ok ok yP

m-Xylene 66 17 31 34,35 ok ok yP 6

o-Xylene 18 2 32 35 ok ok yP 7

p-Xylene 14 1 33 35 ok ok yP 6

1,2,3-Trimethyl benzene 9 2 36 39 ok ok yP

1,2,4-Trimethyl benzene 11 2 37 39 ok ok yP

1,3,5-Trimethyl benzene 21 1 38 39 note note yP 8

Naphthalene 5 40 +1 ok Prm

Tetralin 5 40 +1 ok Prm
Table 23 (continued)

85

Compound or Mixture No. Runs [a] Fig. No. [b] O3-NO Fits [c] Adj [d] Note [e] Single Rct'y Single Rct'y Rate Max

2,3-Dimethyl naphthalene 4 40 +1 +1 Prm

Acetylene 4 7 41 42 -1 -1 9

Methanol 3 43 ok

Ethanol 3 43 ok

Isopropyl alcohol 10 44 ok ok

t-Butyl alcohol 7 45 ok +1 yN

1-Octanol 4 46 ok +1

2-Octanol 3 46 ok +1

3-Octanol 3 46 ok +1

Ethylene glycol 5 47 ok ok 10

Propylene glycol 12 48 ok ok 10

Dimethyl ether 4 49 ok

Diethyl ether 6 49 ok ok yN

Methyl t-butyl ether 4 50 ok

1-Methoxy-2-propanol 6 51 ok +1

2-Ethoxyethanol 3 52 ok

2-(2-Ethoxyethoxy) ethanol 3 52 ok

2-Butoxyethanol 7 53 ok ok

2-(2-Butoxyethoxy)-ethanol 3 54 ok ok yN

Methyl acetate 7 55 ok ok

Ethyl acetate 9 56 ok ok 11

Isopropyl acetate 3 57 ok ok

t-Butyl acetate 6 57 ok +1 yN

Methyl isobutyrate 7 58 ok ok

Methyl pivalate 6 59 ok ok

n-Butyl acetate 8 60 ok +1

Dimethyl carbonate 6 61 ok ok yN

Methyl isopropyl carbonate 5 61 ok ok yN

Propylene carbonate 7 62 -1 ok yN

1-Methoxy-2-propyl acetate 6 63 ok +1 yN

Dimethyl succinate 6 64 ok ok yN

Dimethyl glutarate 6 64 ok ok yN

Texanol® isomers 4 65 ok ok

Furan 8 66 note note yP 12

2-Methyl furan 2 67 ok ok yP

3-Methyl furan 6 67 ok ok yP

2,5-Dimethyl furan 2 67 ok ok yP

Benzyl alcohol 6 3 68 69 ok ok yP

Formaldehyde 33 8 70 71 ok ok

Acetaldehyde 18 5 72 73 ok ok

Acrolein 3 74 ok ok

Methacrolein 12 74 ok ok

Benzaldehyde 3 75 ok ok

Acetone 7 10 76 77 note note QY 13,14

Methyl ethyl ketone 6 5 78 79 ok ok QY 13
Table 23 (continued)

86

Compound or Mixture No. Runs [a] Fig. No. [b] O3-NO Fits [c] Adj [d] Note [e] Single Rct'y Single Rct'y Rate Max

2-Pentanone 1 4 78 80 ok ok QY

2-Heptanone 1 3 78 81 note note QY 15

4-Methyl-2-pentanone 8 81 ok ok

Cyclohexanone 9 82 ok ok

Methyl vinyl ketone 6 83 ok ok

o-Cresol 1 84 ok ok Prm 16

m-Cresol 1 1 84 85 -2 ok? 16,17

p-Cresol 1 84 ok ok? 16,18

Para toluene isocyanate 6 86 ok ok Prm

2,4-Toluene diisocyanate 7 87 ok ok Prm

2,6-Toluene diisocyanate 2 87 ok ok Prm

N-Methyl-2-pyrrolidone 6 88 ok ok yN

N-Propyl bromide 6 89 -1 +2 19

N-Butyl bromide 6 89 -1 +2 19

Trichloroethylene 8 90 +2 +2 20

trans 1,3,3,3-Tetrafluoropropene (See notes) ok ok yN 29,30

2,3,3,3-Tetrafluoropropene (See notes) ok ok yN 29,31

1,3-Dichloropropene mixture 6 3 91 92 ok ok 21

2-(Chloromethyl)-3-chloropropene 1 93 -1 ? 20

Chloropicrin 6 5 94 95 ok ok

Chlorine 2 1 96 ok ok 22

Hexamethyldisiloxane 3 97 ok Prm

Hydroxymethyldisiloxane 4 97 ok Prm

D4 cyclosiloxane 3 97 ok Prm

Carbon disulfide 4 98 ok ok Oth 21

Methyl isothiocyanate 4 98 ok ok Oth 21

Dimethyl sulfoxide 2 6 99 100 -2 ok Oth 23

S-ethyl dipropylthiocarbamate 

(EPTC)

5 101 ok ok Oth 21

Ethanolamine 5 [f] 108 ok [g] Init 27

2-Amino-2-methyl-1-propanol 7 [f] 109 ok [g] Init 28

Isopropyl amine 1 [f] 108 ok [g] +2 Init 27

t-Butyl amine 1 [f] 109 ok [g] +2 Init 28

Methyl Iodide 7 3 [f] 110 111 ok +1 Oth 26

Complex Mixtures

Safety-Kleen mineral spirits "A" 

(type I-b, 91% alkanes)

3 102 ok +1 24

Safety-Kleen mineral spirits "B" 

(type II-c)

3 102 ok +1 24

Safety-Kleen mineral spirits "C" 

(type II-c)

3 102 ok +1 24

Safety-Kleen mineral spirits "D" 

(type II-c)

3 102 ok +1 24
Table 23 (continued)

87

Compound or Mixture No. Runs [a] Fig. No. [b] O3-NO Fits [c] Adj [d] Note [e] Single Rct'y Single Rct'y Rate Max

Exxon Exxol® D95 Fluid 6 103 ok ok 24

Exxon Isopar® M Fluid 5 103 ok ok 24

Oxo-decyl acetate 5 104 ok ok 24

VMP naphtha 4 105 ok ok 24

Kerosene 4 105 ok ok 24

Dearomatized Alkanes, mixed, 

predominately C10-C12 (ASTM1C)

2 106 ok ok 24

Synthetic isoparaffinic alkane 

mixture, predominately C10-C12 

(ASTM3C1)

4 106 ok ok 24,25

Reduced aromatics mineral spirits 

(ASTM1B)

3 106 ok ok 24

Regular mineral spirits (ASTM1A) 3 106 ok ok 24

Aromatic 100 4 107 ok ok 24

[a] Number of chamber experiments. "Single" refers to single VOC - NOx or VOC + CO or alkane -

NOx irradiation; "Rct'y" refers to incremental reactivity experiment.

[b] Figure number in Appendix C where mechanism performance for single VOC or incremental 

reactivity experiments is shown.

[c] Qualitative indication of ability of mechanism to fit initial rates of O3 formation and NO oxidation 

("rate") and final ozone yields ("Max"). The former is more indicative of model performance under 

relatively high NOx, MIR-like conditions, and the latter is indicative of model performance in 

simulating O3 impacts under lower NOx conditions. If blank, then data are not available to evaluate 

this aspect of the mechanism. Codes used are as follows:

ok Model simulates most of the data within the experimental variability, with low or no apparent 

biases.

n Model tends to overpredict (+) or underpredict (-) O3 yield or O3 formation and NO oxidation 

rates. 1 = moderate but apparently consistent biases; 2 = potentially significant biases

? The data are insufficient to evaluate this aspect of the mechanism.

note See note for a discussion of the model performance.

[d] Indicates if mechanism was adjusted to fit the data in this evaluation. Codes indicate the type of 

adjustment, as follows:

yN Nitrate yield in peroxy + NO reaction(s) adjusted

yP Yield of photoreactive products(s)adjusted. For aromatics, this is the AFG1/AFG2 ratio.

Or Radical yield in O3 and O3P reaction adjusted.

QY Quantum yield for photodecomposition adjusted

Prm Parameterized mechanism used with various parameters adjusted.

Oth Other adjustments were made. See references in notes.

Init Initial reactant concentration injected. See Note [g].

[e] Notes and comments concerning the evaluation results of mechanism adjustment, as follows:

1 The model significantly overpredicts the direct reactivity measured by Carter and Malkina (2002) 

(see "Iso-Octane" on Figure 15)

2 The model tends to overpredict O3 in the -pinene - NOx experiments but gives reasonably good 

simulations of the reactivity experiments. 
Table 23 (continued)

88

3 Model overpredicts O3 formation rate in the arc light benzene - NOx experiments but tends to 

underpredict it in the blacklight runs. Model gives reasonably good simulation of most of the 

incremental reactivity experiments. 

4 The model underpredicts the direct reactivities measured by Carter and Malkina (2002), but not 

as much as SAPRC-99 (see Figure 15).

5 Model overpredicts initial NO oxidation and O3 formation rates in the toluene - NOx blacklight 

experiments but gives good simulations to these experiments in the TVA chamber and in 

chambers using arc lights. Model gives good simulations of the incremental reactivity results. The 

model significantly overpredicts the reactivity seen in the toluene - NOx experiments in the UNC 

outdoor chamber, but this could be due to chamber characterization problems. The model 

underpredicts the direct reactivities measured by Carter and Malkina (2002), but not as much as 

SAPRC-99 (see Figure 15).

6 The model underpredicts the effects of CO addition on O3 formation, though to a lesser extent 

than SAPRC-99 (see Figure 8).

7 The model somewhat overpredicts the reactivity seen in the o-xylene - NOx experiments in the 

UNC outdoor chamber, but this could be due to chamber characterization problems.

8 The model tends to overpredict O3 formation in experiments in the EC but gives good simulations 

to results of more recent experiments using both blacklights and arc lights. The model somewhat 

overpredicts the direct reactivities measured by Carter and Malkina (2002), but the discrepancy 

may be within the uncertainty of the measurement.

9 The model consistently underpredicts the reactivities in the acetylene - NOx experiments, but the 

underprediction of the incremental reactivity results is relatively small. The SAPRC-99 

mechanism, which uses a higher rate constant for OH + acetylene based on an earlier 

recommendation by Atkinson (1994), simulates the data with much less bias. This rate constant 

was changed to reflect the recommendation in the NASA (2006) evaluation. 

10 Even though the mechanism was not changed, the model performs somewhat better than SAPRC99 in simulating some experiments.

11 The model somewhat underpredicts the direct reactivity measured by Carter and Malkina (2002) 

(see Figure 15).

12 The model gives reasonably good simulations of earlier ITC experiments but tends to 

underpredict maximum O3 in the new arc light and blacklight experiments carried out for this 

project.

13 See base mechanism documentation (footnotes to Table A-2) for a discussion of the adjustments 

made for this compound.

14 The reactivity is somewhat underpredicted in the acetone - NOx experiments with the arc lights 

and in the outdoor chamber but is well simulated in the blacklight chamber runs. The incremental 

reactivity results are reasonably well simulated.

15 The model evaluation results for this compound are highly variable. O3 formation in the single 

heptanone - NOx experiment is significantly underpredicted, but the reactivity in one of the two 

incremental reactivity experiments is overpredicted, while the other two incremental reactivity 

experiments are reasonably well simulated. The latter were used as the basis for adjusting the 

photolysis rate, which was an important uncertain parameter in affecting the results. Note that the 

photolysis rate adjusted to fit this compound affects the base mechanism because the photolysis 

rate used for the lumped higher ketone product, PROD2, is based primarily on the photolysis rate 

derived for this compound. 
Table 23 (continued)

89

16 The parameterized mechanism used for all the cresol isomers was adjusted to fit the data for ocresol based on the model simulation of a single experiment. The ([O3]-[NO]), cresol and PAN 

data in that one experiment are simulated reasonably well.

17 The model underpredicts O3 formation in the m-cresol - NOx experiment and gives an incorrect 

prediction of the effect of o-cresol addition on the initial NO oxidation and O3 formation rate in 

the reactivity experiment, but simulates the effect on final O3 reasonably well.

18 The one p-cresol - NOx experiment is simulated reasonably well.

19 No attempt was made to adjust the approximate mechanisms to fit the chamber data. The 

performance indicates the performance of the approximation of using chlorine mechanisms to 

estimate mechanisms for Br-containing species.

20 No attempt was made to adjust this mechanism to improve simulations of the data.

21 See Carter and Malkina (2007) for a discussion of adjustments made to these mechanisms to fit 

the chamber data. 

22 The effects of Cl2 on n-butane - NOx irradiations and the effects of multiple Cl2 additions to a 

surrogate - NOx experiment were reasonably well simulated.

23 The initial NO oxidation and O3 formation rates are significantly underpredicted in the DMSO -

NOx experiments but are only slightly underpredicted in the MIR-type incremental reactivity 

experiments. Except for one experiment where the model overpredicts DMSO reactivity, the 

effects of DMSO on final O3 in the lower NOx reactivity experiments are reasonably well 

simulated.

24 The mechanism evaluation with these complex mixtures primarily tests how well the mixtures are 

represented by the distribution of model species used to represent them. No mechanism 

adjustments can be made to improve simulations in these cases.

25 The model performance with this version of the mechanism is considerably better than SAPRC99, which had a consistent bias in underpredicting the O3 impact (overpredicting the O3

inhibition) of this mechanism. 

26 See Carter (2007) for a discussion to the adjustments made to this mechanism to fit the chamber 

data. The mechanism tends to underpredict the amount of ozone inhibition caused by the addition 

of methyl iodide at the end of some of the experiments.

27 See Note [g] and Carter (2008a) for a discussion of the amine experiments. Although the amount 

of initial amine in the experiments are adjusted to fit the effects of the amine on the initial rates of 

NO oxidation and O3 formation in the experiments (see Note [g]), the model does not predict the 

observed inhibition of ozone at the end of the lower NOx experiments. 

28 See Note [g] and Carter (2008a) for a discussion of the amine experiments. Because these 

compounds significantly inhibited the rates of O3 formation, the ability of the mechanism to 

simulate the effects of the amine on final O3 yields could not be determined.

29 See the report cited in the other note for the results of the evaluation experiments for these 

compounds, which were carried out after the list of experiments to be included in this report was 

finalized.

30 See Carter (2009a) for a discussion of the experiments used to evaluate the mechanism for this 

compound. Good simulations of MIR and MOIR/2 reactivity experiments were obtained after 

adjusting the overall nitrate yield.

31 See Carter (2009b) for a discussion of the experiments used to evaluate the mechanism for this 

compound. Good simulations of MIR and higher ROG/NOx reactivity experiments were obtained 

after adjusting the overall nitrate yield.
Table 23 (continued)

90

[f] These experiments that were not in the original (August, 2007) version of the report.

[g] Amount of injected amine available for reaction is uncertain because initial concentration of the 

amine in the gas phase could not be measured, and because of expected absorption of amines on the 

walls and other heterogeneous effects. The fits indicated on the table reflect the fits obtained after 

adjusting initial amount of amine to fit the initial rates of NO oxidation and O3 formation in the 

experiments, and the adjusted initial amine concentrations were always lower than the calculated 

amount injected. See Carter (2008a). The figures show the fits with the amount of initial amine 

adjusted to best fit the data.

in footnotes to the table. The figures in Appendix C show the model performance for both SAPRC-99 and 

SAPRC-07, but Table 23 only summarizes the results for SAPRC-07, though cases where the 

mechanisms differ significantly are noted.

For the vast majority of the VOCs and mixtures, the performance for SAPRC-07 was 

similar to that of SAPRC-99, though as indicated on Table 23, mechanism parameters had to be adjusted 

to obtain the comparable fits. This is expected, since for most VOCs the mechanisms were not 

significantly changed. Exceptions and other cases worth noting are as follows:

Alkylbenzenes. As discussed above, significant changes were made to the ring-opening

mechanisms for the alkylbenzenes and the model species used to represent the non--dicarbonyl ring 

opening products. However, these changes did not result in significant changes in the ability of the model 

to simulate aromatic - NOx experiments or incremental reactivity experiments with aromatics, presumably 

because portions of both mechanisms were optimized to simulate essentially the same database. Like 

SAPRC-99, the updated mechanism also tended to underpredict the effects of adding CO to aromatics -

NOx irradiations, but to a lesser extent than SAPRC-99. This is shown on Figure 8, which shows results 

of selected toluene and m-xylene - NOx experiments where CO was added. Likewise, as discussed below, 

the updated mechanisms also tended to overpredict direct reactivities of benzene and toluene, but again to 

a lesser extent than SAPRC-99. Therefore, the overall performance of the updated mechanism is an 

improvement over SAPRC-99 in some at least some respects, but problems in simulating all of the data 

still remain.

Alkenes. As also indicated above, it was necessary to assume lower radical yields in the 

reactions of O3 and O3P with alkenes than indicated by current laboratory data in order to obtain unbiased 

simulations of the data. This was the case for SAPRC-99 and is also the case with this updated 

mechanism. However, the extent to which the yields had to be adjusted to lower values was somewhat 

less with this version of the mechanism, so at least in this respect the problem may be slightly reduced.

Acetylene. The current NASA (2006) evaluation recommends an OH + acetylene rate 

constant that is lower than that used in SAPRC-99 by ~17% at ambient temperature and pressure. This 

caused a negative bias in the model simulations of the acetylene experiments that was not the case for 

SAPRC-99. However, this bias was not so large that it was considered appropriate to adjust the rate 

constant, and there were not other uncertain aspects of the mechanism considered to be appropriate to 

adjust to remove this bias.

Higher Ketones. The photolysis rate used in the base mechanism for the lumped model 

species used to represent the more reactive ketone products, PROD2, is based on overall quantum yields 

derived based on model simulations of the experiments with methyl propyl ketone, methyl isobutyl 
91

Figure 8. Experimental and calculated effects of CO addition in representative toluene and 

m-xylene NOx experiments carried out in the UCR EPA chamber.

ketone and 2-heptanone. The data indicate that the quantum yields decrease with carbon number, but the 

extent of the decrease with the higher ketones is somewhat greater with the updated mechanism than 

SAPRC-99. This resulted in a lower overall photolysis rate for the PROD2 model species. However, the 

very limited and somewhat consistent data for 2-heptanone provides the only information about ketones 

with greater than 7 carbons, which are used as the basis for the even larger ketones that are important in 

alkane and other photooxidations. More data are needed to place the estimates for photolysis rates of 

higher ketones on a firmer basis.

Alkyl Bromides. Since developing mechanisms for bromine species was beyond the 

scope of this project, the mechanisms for the few bromine-containing compounds that are represented are 

estimated based on mechanisms derived for the corresponding chlorine-containing compounds. The 

chamber data for n-propyl and n-butyl bromides, shown on Figure C-89, indicate that this may somewhat 

underestimate the rate of initial NO oxidation and O3 formation but significantly overestimate the impact 

of the compound on final O3 yields. The implication of this on predicted MIR values for these compounds 

is uncertain, but it is clear that low NOx reactivities of these compounds are almost certainly 

overestimated.

Isoparaffinic Alkane Mixtures. Carter and Malkina (2005) noted that the SAPRC-99 

mechanism predicted much more O3 inhibition in the incremental reactivity experiments with the 

synthetic isoparaffinic alkane mixture (designated ASTM3C1) than observed experimentally, and 

concluded that there is a problem either with the characterization of such mixtures or with branched 

alkane mechanisms in general. However, although neither the composition of the mixture nor the 

branched alkane mechanisms were changed, the updated mechanism now gives much better simulations 

of these data, as shown on Figure C-106. This indicates that reactivities of compounds such as these, and 

presumably others, can be sensitive to changes in the base mechanism that has nothing directly to do with 

the mechanisms for the compounds themselves. 

Toluene - NOx m-Xylene - NOx

EPA077 (~25 ppb NOx) EPA066 (~5 ppb NOx) EPA067 (~20 ppb NOx)

Irradiation time (minutes)

([O3

]-[NO]) (ppm) ([O3

]-[NO]) Change

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 60 120 180 240 300 360

0.00

0.05

0.10

0.15

0 60 120 180 240 300 360

0.00

0.02

0.04

0.06

0.08

0 60 120 180 240 300 360

-0.01

0.00

0.01

0.02

0.03

0 60 120 180 240 300 360

0.00

0.03

0.06

0.09

0.12

0 60 120 180 240 300 360

0.00

0.02

0.04

0.06

0 60 120 180 240 300 360

Arom. - NOx + CO Experiment SAPRC-99 Model

Aromatic - NOx Experiment SAPRC-07 Model
92

Amines. The mechanisms for amines were newly derived for this mechanism; SAPRC-99 

either has no mechanisms for these compounds or uses highly approximate "placeholder" mechanisms. 

The amine mechanisms derived for SAPRC-07 are and are discussed above in the "Mechanisms for 

Individual VOCs" section and in more detail by Carter (2008a). A series of incremental reactivity 

environmental chamber experiments were carried out with 2-amino-2-methyl-1-propanol (AMP) and 

ethanolamine and one experiment each was carried out for t-butyl amine and isopropyl amine (Carter, 

2008a), and selected results are shown on Figure C-108 and Figure C-109. As discussed by Carter 

(2008a), because of analytical problems no data were available concerning the amount of amines present 

in the gas phase at the start of the experiments, and if the amount of initial amine derived from the 

calculated amounts injected is assumed, then the effects of the amines on the results of the experiments 

are significantly overpredicted. This is even if it is assumed that the amines react rapidly with HNO3

formed in the experiments to form the corresponding salt, which is also assumed to be removed from the 

gas-phase system. Therefore, the amount of amine initially present in the gas phase had to be treated as an 

adjustable parameter in the model simulations of the experiments, in order to obtain the fits shown on 

Figure C-108 and Figure C-109. The amount of initial amine that best fit the reactivity data ranged from 

~5% to ~60% of the calculated amount of amine injected, with no apparent dependence on reaction 

conditions or type of experiment (Carter, 2008a). Because of this, the use of these experiments to evaluate 

amine mechanisms is highly uncertain. Nevertheless, the estimated mechanisms correctly predict that 

AMP and t-butyl amine significantly inhibit NO oxidation O3 formation, while they correctly predict that 

the other two amines have positive effects on initial NO oxidation and O3 formation rates.

When the amounts of initially present amines are appropriately adjusted to simulate the 

effects on initial NO oxidation rates, Figure C-109 shows that the data for AMP and t-butyl amine are 

reasonably well simulated throughout the experiments. On the other hand, as shown on Figure C-108, the 

chamber data indicated that the two reactive amines studied, aminoethanol and isopropyl amine, tended to 

inhibit O3 formation under low NOx conditions, which was not predicted by the mechanism. The reason 

for this inhibition is unknown, and this discrepancy could not be resolved by reasonable adjustments to 

the mechanisms for these compounds and the representations of the reactions of their major products 

(Carter, 2008a). Therefore, it must be concluded that the mechanisms for the positively reactive amines 

probably overpredict the reactivities of the compounds under low NOx conditions, if the uncertainties 

regarding availability are not considered.

Methyl Iodide. Methyl iodide is another compound that was not represented in 

SAPRC-99 but whose mechanism has been derived for SAPRC-07. The mechanism for this compound, 

and its evaluation against chamber data, are described in detail by Carter (2007), and that discussion is not 

duplicated here. Figure C-110 and Figure C-111 show that the mechanism simulates most of the data of 

Carter (2007) reasonably well.

Evaluation Experiments for Mixtures

Figure 9 through Figure 13 show distribution plots for the various types of mixture - NOx

experiments in the current evaluation set. For most types of mixtures the model performance is generally 

satisfactory in terms of overall biases, but there are cases where the updated mechanism does not perform 

quite as well as SAPRC-99. These are discussed below for the various types of experiments.

Simple mixture experiments. These are runs with mixtures that are not considered to be 

complete surrogates because they do not contain at least one representative each of alkanes, alkenes, and 

aromatics. Figure 9 shows distributions of model errors for these runs, grouped by the chamber employed. 

It shows that the average biases and distribution of errors are similar for both mechanisms. The mixture 

experiments in the TVA and UCR EC chamber are reasonably well simulated, while the reactivity 

experiments in the mixture experiments in the UNC chamber are overpredicted by about the same amount 

in both mechanisms. Given the good performance for the quite different EC and TVA chambers, the 
93

poorer performance in simulating the UNC chamber data is considered to be likely due to characterization 

rather than mechanism problems.

Miscellaneous Surrogate Experiments. These are experiments with mixtures that contain 

at least one alkane, alkene and aromatic that are designed to represent, albeit in a simplified fashion, 

reactive organic gas mixtures that are emitted into ambient atmospheres. The more recent experiments in 

the UCR EPA chamber are considered separately because they were carried out at generally lower 

pollutant levels than the earlier chamber experiments, and conditions in that chamber are considered to be 

somewhat better characterized. Figure 10 shows the distribution of model errors in the earlier surrogate -

NOx experiments carried out in various UCR and the TVA chamber, and Figure 11 shows the results for 

various surrogate mixtures in the UNC chamber. Because of the large number of the many standard 

surrogate experiments used as base cases in incremental reactivity studies in the UCR chambers, these are 

excluded from Figure 10 and are shown separately in Figure 12. Overall the model performance for the 

updated mechanism is similar to SAPRC-99 for these experiments, though the biases tend to be somewhat 

more (either positive or negative, depending on the type of experiment) for the miscellaneous mixtures 

shown on Figure 10. The results with both mechanisms for the UNC or UCR standard surrogate runs, 

shown on Figure 11 and Figure 12, respectively, are similar for both mechanisms, with the reactivity in 

the UNC experiments again being consistently overpredicted (though not as much so as for the simple 

mixture runs shown on Figure 9), and the earlier UCR standard base case surrogate runs being well 

simulated.

New Surrogate Experiments in UCR EPA Chamber. A large number of surrogate - NOx

experiments have been carried out in the new UCR EPA chamber, most based on a similar 7- or 8-

compound mixture designed to represent ambient VOC mixtures (Carter et al, 1995c, Carter and Malkina, 

2005)1. As discussed by Carter (2004), a large number of such experiments were carried out at a variety 

of NOx and ROG levels, including NOx levels as low as 2 ppb, giving a large and reasonably well 

characterized database for testing model predictions of how O3 changes with ROG and NOx levels. The 

results indicated a bias in the SAPRC-99 mechanism in underpredicting O3 formation and NO oxidation 

at low ROG/NOx levels, which have not been seen in simulating the earlier surrogate experiments carried 

out at higher NOx levels (Carter, 2004; Carter et al, 2005b). Since then, a number of other experiments 

have been carried out in this chamber to further investigate this, including experiments using the 

blacklight light source and experiments using a "non-aromatic" surrogate with the aromatic constituents 

of the 7- or 8- compound surrogate mixture removed. The latter are useful to evaluate whether the bias at 

low ROG/NOx is due to problems with the aromatics mechanisms, which are considered to be the most 

uncertain component of the overall mechanism for mixtures.

The performance of the mechanisms in simulating these experiments is shown in Figure 

13 and Figure 14. Figure 13 shows distribution plots of model errors similar to those shown above for 

other mixtures, and shows that overall the updated mechanism simulates the full surrogate (i.e., the 

surrogates with the aromatics) approximately as well as SAPRC-99, but that the updated mechanism has a 

slight positive bias in overpredicting O3 formation and NO oxidation rates in the non-aromatic surrogate 

runs. Figure 14 shows plots of model errors against the ROG/NOx ratio, similar to those shown previously 

(Carter, 2004; Carter et al, 2005b). This shows that the problem with the model underpredicting O3.

 

1 The 7-compound surrogate was the same as the 8-compound surrogate except that formaldehyde was 

removed because of experimental issues. Carter and Malkina (2005) showed that this removal should not 

significantly affect experimental or mechanism evaluation results.
94

Figure 9. Plots of model errors in simulations of miscellaneous mixture - NOx experiments carried 

out in various chambers.

Miscellaneous Simple Mixture Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

EC Chamber 25 0% 9% -14% 5%

TVA chamber 6 -8% 3% -16% -6%

UNC Chamber 32 74% 33% 63% 33%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

75%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

75%

1 2 3 4 5 6

EC Chamber

TVA chamber

UNC Chamber

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
95

Figure 10. Plots of model errors in simulations of miscellaneous surrogate - NOx experiments 

carried out in various UCR chambers and in the TVA chamber.

Miscellaneous Surrogate Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

ETC, DTC Runs 35 24% 7% 47% 17%

ITC 4 HC Mix 35 27% 12% 31% 15%

ITC 8 HC Mix 14 -30% -13% -36% -20%

EC 7 HC Mix 11 24% 27% 15% 21%

TVA Surrogates 22 -16% -8% -23% -13%

OTC 8 HC Mix 4 -10% -3% -13% -5%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

ETC, DTC Runs

ITC 4 HC Mix

ITC 8 HC Mix

EC 7 HC Mix

TVA Surrogates

OTC 8 HC Mix

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
96

Figure 11. Plots of model errors in simulations of surrogate - NOx experiments carried out in the 

UNC chamber.

UNC Chamber Surrogate Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Simple Mix 9 18% 21% 7% 25%

SynUrban 11 45% 39% 34% 27%

SynAuto 14 12% 32% 8% 26%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Simple Mix

SynUrban

SynAuto

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
97

Figure 12. Plots of model errors in simulations of the standard base case surrogate - NOx irradiations 

carried out in conjunction with the incremental reactivity experiments in the ETC and 

DTC (blacklight), and CTC and XTC (arc light) chambers. 

Earlier Chamber Standard Base Case Surrogate Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc, Surg-3 MIR1 40 21% 7% 6% -6%

Arc, Surg-8 MIR1 40 2% 5% 0% 4%

Arc, Surg-8 LN1 21 -1% 0% 4% 2%

Black, Surg-3 MIR1 227 13% 3% 22% 7%

Black, Surg-8 MIR1 114 -1% 2% 13% 7%

Black, Surg-8 LN1 96 1% 3% 10% 7%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc, Surg-3 MIR1

Arc, Surg-8 MIR1

Arc, Surg-8 LN1

Black, Surg-3

MIR1

Black, Surg-8

MIR1

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
98

Figure 13. Plots of model errors in simulations of the surrogate - NOx experiments carried out in the 

UCR EPA chamber. 

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Full Surg, Arc 111 -10% -10% -14% -14%

Full Surg, Black 75 -19% -14% -8% -11%

Non-Arom Surg, Arc 3 -1% 4% 15% 11%

Non-Arom Surg, Black 23 -3% -2% 13% 8%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Full Surg, Arc

Full Surg, Black

Non-Arom Surg, Arc

Non-Arom Surg,

Black

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
99

Figure 14. Plots of model errors in simulations of 6-hour ([O3]-[NO]) against initial ROG surrogate 

/NOx ratio.

formation and NO oxidation rates at the lower ROG/NOx ratios has not been eliminated, and that the 

extent to which the bias is affected by ROG/NOx ratios is essentially the same. This is observed in the 

blacklight as well as the arc light chamber experiments.

On the other hand, Figure 14 shows that if the aromatics are removed, the dependence of 

the bias on ROG/NOx is in the opposite direction as seen with the full surrogate, with the model tending 

to overpredict reactivity more at lower ROG/NOx ratios, and giving better predictions of the data at the 

higher ROG/NOx conditions. This is true for both versions of the mechanism, but has been somewhat 

exacerbated as a result of the mechanism update

Overall, the evaluation with the experiments with mixtures indicate a slight degradation 

of model performance for the updated mechanism compared to SAPRC-99, though this is not seen for all 

types of mixtures. Figure 7, above shows a very slight (~5%) bias in the updated mechanism in simulating 

the mixture experiments when all are lumped together, with the bias being greater (~10%) in simulating 

initial NO oxidation and O3 formation rates. However, when examining run types separately, one sees the 

biases vary with type of experiment, with some types of experiments having greater positive biases and 

some having greater negative biases, compared to SAPRC-99. 

The difference for the UCR EPA full surrogate vs. non-aromatic surrogate at low 

ROG/NOx conditions is suggestive, with the experiments with the aromatics having the distinct negative 

bias while those with aromatics removed having the bias in the opposite direction. But the evaluations of 

Full Surrogate (Surg-7 or Surg-8)

Arc Lights Blacklights

Non-Aromatic Surrogate (Surg-NA), Blacklights

Surrogate /NOx Ratio (ppmC/ppm)

([O3

]-[NO]) Model Error

-50%

-25%

0%

25%

1 10 100 1000

SAPRC-99

SAPRC-07

-50%

-25%

0%

25%

1 10 100 1000

-25%

0%

25%

1 10 100 1000
100

the single compound or incremental reactivity experiments with the individual alkanes, alkenes, and 

aromatics, shown in figures in Appendix C and summarized on Table 23 above, do not indicate trends in 

biases with individual compounds that is consistent with this. The cause and significance of this problem

is uncertain, and clearly this needs further study. It is important to note, however, the biases are not large 

compared to overall run-to-run variability and characterization uncertainties in model simulations of 

environmental chamber experiments.

Mechanism Performance for Direct Reactivity Experiments

Figure 15 shows the model performance in simulating the direct reactivity experiments of Carter 

and Malkina (2002) for all the compounds for which useful direct reactivity data were obtained. The 

results for SAPRC-99 are also shown. Except for benzene and toluene the results were very similar for the 

two mechanisms, with generally good fits being obtained for most compounds except for isooctane 

(2,2,4-trimethylpentane) and ethyl acetate. This is as expected since the mechanisms for these compounds 

were not changed significantly. The reasons for the discrepancies for isooctane and ethyl acetate are 

unknown, and have not been resolved.

Figure 15 shows that the new aromatics mechanisms do perform somewhat better in simulating 

the direct reactivities for benzene and toluene, though the direct reactivities of these compounds, and to a 

lesser extent 1,3,5-trimethylbenzene, are still overpredicted. This can be attributed to the updated 

mechanism assuming direct OH formation, without NO to NO2 conversions, in the ring opening pathways 

that do not involve -dicarbonyl formation. However, the results suggest that actual total amount of NO 

to NO2 conversion may still be less than assumed in this mechanism.

Figure 15. Model performance in simulating the direct reactivity data of Carter and Malkina (2002).

0.0

0.5

1.0

1.5

2.0

2.5

C

O

Ethane

Propane (avg)

n-Hexane

n-Octane (avg.)

n-Decane

n-C12n-C13n-C14n-C16

Iso-Octane

Ethyl Acetate

MEK

Propene

Benzene

Toluene

1,3,5-TM. Benzene

Direct Reactivity Measurement / kOH

(Relative to Ethane)

Experimental SAPRC-99 SAPRC-07
101

UPDATED REACTIVITY SCALES

One of the major applications of the SAPRC mechanisms is calculation of ozone reactivity scales 

for VOCs, including the MIR scale that is used or being considered for use in regulatory applications 

(CARB 1993, 2000, 2006, 2007), and a major reason behind this mechanism update is to update these 

reactivity scales. The SAPRC-99 mechanism was used to calculate MIR and other reactivity scales for 

many types of VOCs, with the latest update being that of Carter (2003a). That update includes reactivities 

for almost 780 types of VOCs, based on explicit or assigned mechanisms for ~560, and lumped molecule 

or mixture assignments for the rest. The listing included uncertainty codes for the reactivity estimates that 

may be potentially useful for regulatory applications or determining priorities for research. These scales, 

and their corresponding uncertainty classifications, have been updated as part of this project.

Methods

The methods, scenarios, and reactivity scales that were used in this reactivity scale update are the 

same as employed previously for the SAPRC-99 scales (Carter 2000a, 2003), and those references should 

be consulted for detail. Briefly this is based on the methods and scenarios originally developed by Carter 

(1994a,b), with slight modifications in the averaging methods as described by Carter (2000a). These are 

based on 39 single-day "base case" EKMA box model scenarios (EPA, 1984) derived by the EPA for 

assessing how various ROG and NOx control strategies would affect ozone nonattainment in various areas 

of the country (Baugues, 1990). The conditions of these scenarios are summarized on Table 24, and more 

details concerning the modeling inputs are given by Carter (1994b).

The scenario conditions include specifications of initial concentrations and emissions schedules 

for NOx and total anthropogenic VOC emissions and also background O3, aloft VOCs, and initial and 

emitted biogenic VOCs (Bauges, 1990; Carter, 1994a,b). The scenarios as originally developed by 

Bauges (1990) do not specify the composition of the anthropogenic VOCs, and Carter (1994a) used a 

standard mixture of hydrocarbons derived by Jeffries (Jeffries et al (1989) from analysis of air quality 

data, with minor modifications as discussed by Carter (1994a,b). This is referred to as the "Base ROG 

mixture" in the subsequent discussion. This base ROG mixture was not modified for the SAPRC-99 

reactivity scale updates (Carter, 2000a, 2003a), and was also used in this update. Note that same base 

ROG mixture was used as the basis for deriving the "fixed parameter" version of the SAPRC-07 

mechanism for airshed models, as discussed above. The composition of this mixture in terms of fixed 

parameter SAPRC-07 lumped model species in given in Table 17, above.

The base case scenarios with the NOx inputs as specified by Bauges (1990) were used to derive 

the updated "base case" reactivity scales, comparable to those given by Carter (1995a, 2000a) for 

SAPRC-90 or SAPRC-99. Because absolute and even relative impacts of VOCs on O3 formation are 

highly dependent on NOx conditions that are highly variable in the base case scenarios, scenarios with 

adjusted NOx inputs were derived to obtain scales that are more representative of standard conditions of 

conditions of NOx availability. These are as follows:

 The Maximum Incremental Reactivity (MIR) scale is derived from the scenarios where the NOx

inputs are adjusted to yield highest incremental reactivities (changes in O3 caused by small VOC 

additions, divided by the amount of VOC added) of VOCs. Although the NOx conditions yielding

highest incremental reactivities tend to be the same for most VOCs, the sensitivity of O3

formation to changes in total base ROG inputs was used to determine the NOx levels 

corresponding to MIR conditions. This represents relatively high NOx conditions where, by 

definition, O3 is most sensitive to changes in VOC emissions. 
102

Table 24. Scenarios used for reactivity assessment, with updated calculated maximum O3, 

Integrated OH, and MIR, MOIR, and EBIR NOx inputs.

Scenario Max O3

(ppb)

Max 8-Hr 

Avg O3

(ppb)

ROG / NOx [a] Max 

Height 

(kM)

ROG 

input 

[b]

O3 aloft 

(ppb)

Int'd OH

Base MIR MOIR (ppt-min) EBIR

Averaged Conditions (Used for screening calculations and sensitivity studies)

Max React (MIR) 179 117 3.70 1.8 15 70 121

Max O3 (MOIR) 229 161 5.63 1.8 15 70 200

Eq. Benefit (EBIR) 213 166 8.86 1.8 15 70 200

Base Case (Used for MIR, MOIR, and EBIR scales)

Atlanta, GA 173 127 7.25 3.54 5.37 7.66 2.1 12 63 198

Austin, TX 171 141 9.30 3.36 5.08 8.00 2.1 11 85 180

Baltimore, MD 318 196 5.15 3.90 5.92 10.04 1.2 17 84 171

Baton Rouge, LA 237 168 6.83 4.31 6.36 8.46 1.0 11 62 186

Birmingham, AL 239 198 6.94 2.71 4.09 6.26 1.8 13 81 204

Boston, MA 191 161 6.50 2.69 4.13 6.53 2.6 14 105 250

Charlotte, NC 139 123 7.79 1.80 2.78 3.86 3.0 7 92 207

Chicago, IL 286 230 11.63 4.29 6.39 9.75 1.4 25 40 176

Cincinnati, OH 196 145 6.38 3.29 5.05 9.01 2.8 17 70 208

Cleveland, OH 245 170 6.62 4.24 6.64 10.09 1.7 16 89 180

Dallas, TX 194 128 4.74 3.99 6.10 8.86 2.3 18 75 160

Denver, CO 197 132 6.33 4.88 7.37 11.37 3.4 29 57 140

Detroit, MI 237 168 6.82 3.64 5.55 9.85 1.8 17 68 224

El Paso, TX 178 130 6.59 4.49 6.96 9.70 2.0 12 65 136

Hartford, CT 167 140 8.39 2.74 4.26 7.09 2.3 11 78 213

Houston, TX 303 206 6.08 3.94 5.96 9.36 1.7 25 65 217

Indianapolis, IN 205 141 6.64 3.87 6.22 9.61 1.7 12 52 203

Jacksonville, FL 150 111 7.62 3.44 5.18 7.22 1.5 8 40 202

Kansas City, MO 152 120 7.09 2.95 4.59 8.34 2.2 9 65 221

Lake Charles, LA 289 211 7.42 3.46 5.01 6.91 0.5 7 40 235

Los Angeles, CA 566 401 7.59 5.11 7.75 11.08 0.5 23 100 136

Louisville, KY 204 148 5.53 3.10 4.77 7.17 2.5 14 75 248

Memphis, TN 224 174 6.78 3.21 4.79 7.59 1.8 15 58 240

Miami, FL 129 108 9.63 2.71 4.19 6.09 2.7 9 57 178

Nashville, TN 162 134 8.05 2.46 3.74 5.79 1.6 7 50 224

New York, NY 371 293 8.09 4.59 6.41 9.54 1.5 39 103 161

Philadelphia, PA 237 157 6.18 3.98 6.00 9.44 1.8 19 53 213

Phoenix, AZ 271 189 7.58 4.87 7.61 12.98 3.3 40 60 155

Portland, OR 160 121 6.46 2.90 4.66 6.68 1.6 6 66 223

Richmond, VA 233 162 6.18 3.44 5.25 9.30 1.9 16 64 204

Sacramento, CA 198 136 6.59 3.73 5.75 8.89 1.1 7 60 200

St Louis, MO 311 194 6.08 4.55 6.93 11.51 1.6 26 82 167

Salt Lake City, UT 181 147 8.47 3.36 5.30 8.96 2.2 11 85 182

San Antonio, TX 124 90 3.92 2.85 4.42 6.11 2.3 6 60 173

San Diego, CA 188 142 7.09 4.54 6.86 9.63 0.9 8 90 141

San Francisco, CA 231 124 4.77 5.99 8.86 11.87 0.7 25 70 62

Tampa, FL 219 141 4.36 3.32 4.93 6.71 1.0 8 68 192

Tulsa, OK 221 149 5.31 3.08 5.06 8.57 1.8 15 70 242

Washington, DC 274 198 5.32 3.06 4.59 7.22 1.4 13 99 225

[a] Ratio of initial + emitted anthropogenic reactive organic gas (ROG) input to initial + emitted NOx. Biogenic 

VOC input not included.

[b] Initial + emitted anthropogenic VOC input, in units of millimoles m-2.
103

 The Maximum Ozone Incremental Reactivity (MOIR) scale is derived from the scenarios where 

NOx inputs are adjusted to yield highest maximum O3 concentrations. This represents NOx

conditions that are most favorable to O3 formation. MOIR NOx levels are generally about a factor 

of 1.5 lower than those yielding maximum incremental reactivities.

 The Equal Benefits Incremental Reactivity (EBIR) scale is derived from scenarios where NOx

inputs are adjusted so that the reduction in O3 caused by reducing base ROG inputs are the same 

as those caused by changing total NOx inputs by the same percentage. This represents the lowest 

NOx conditions where controls of VOCs are at least as effective as controlling NOx; since for 

lower NOx levels NOx controls are always more effective for reducing O3. EBIR NOx levels are 

generally about a factor of 1.5 lower than those yielding maximum O3 concentrations, or 2.3 

times lower than MIR levels.

Table 24 gives the NOx levels that correspond to these various conditions of NOx availability that 

were used to derive the MIR, MOIR, or EBIR scales. The incremental reactivities for those scales were 

averages of the incremental reactivities calculated for the 39 scenarios of the various types.

The fixed parameter version of SAPRC-07 with the base ROG mixture composition given in 

Table 17 was used to simulate the base cases for the reactivity assessment scenarios used in this work. For 

the purpose of calculating incremental reactivities of individual compounds, model species were added to 

explicitly represent the compound, and also to represent the more reactive oxidation products if the 

"adjustable products" mechanisms were employed. For simulating reactivities of complex mixtures, 

lumped model species were added as indicated on Table 17, above, with the mechanisms for the 

adjustable parameter species (ALKn, OLEn, and AROn) being derived based on the particular mixture 

being assessed. 

Note that as discussed by Carter (2008a) the impacts of the reactions of amines with HNO3 under 

atmospheric conditions are very uncertain. This is because they are sensitive to atmospheric sources and 

other sinks of HNO3, which are highly variable and not determined for the reactivity assessment 

scenarios. For the purpose of deriving reactivity scales for regulatory applications, it is probably 

appropriate to use upper limit estimates of the ozone impacts of these compounds under conditions where 

they will have their highest impacts. For that reason, the atmospheric reactivities calculated for the amines 

are based on assuming that loss by reaction with HNO3 is negligible. As discussed by Carter (2008a) if 

this reaction is important the magnitudes of the O3 impacts of the amines could be lower by more than an 

order of magnitude.

The incremental reactivity calculations were carried out by adding the amount of test compound 

or mixture such that the estimated amount reacted would be 0.05% the mole carbon of the base ROG 

input. The incremental reactivities were calculated change in final (i.e., maximum) O3 concentrations in 

terms of total moles formed, divided by the moles of test compound or mixture added in the calculations. 

The incremental reactivities are then converted from mole to mass basis by using the molecular weights 

for O3 and the test VOCs.

Results

Predicted Ozone Formation in the Scenarios

Before presenting the incremental reactivity results, it may be of interest to show the model 

predictions of O3 formation in the various scenarios used for reactivity assessment. The maximum O3

formed in the base case (unadjusted NOx) scenarios are tabulated in Table 24, and Figure 16 shows 

predicted maximum O3 levels for all scenarios used, plotted against total ROG inputs, which gives a 
104

Figure 16. Plots of maximum O3 concentrations calculated for the various scenarios used for 

reactivity assessment against the initial ROG levels in the scenarios.

measure of the total amount of pollution in the scenario. As expected the O3 levels correlate with the total 

amount of ROG input, though the correlation is not perfect, indicating the importance of other factors 

such as dilution, etc. As also expected (and by definition) the O3 levels are highest for the MOIR 

scenarios, and in all cases are the lowest for the MIR scenarios. 

Note that some scenarios have O3 levels as high as 500 ppb or more, which are much higher than 

now occurs in urban areas in the United States. This suggests that the scenarios should be updated to 

reflect present conditions. However, updating the scenarios for reactivity assessment was beyond the 

scope of this project. Figure 17 shows the changes in O3 formation in the various scenarios predicted 

using this updated version of the mechanism, compared to those calculated previously using SAPRC-99. 

Figure 17a shows the differences when the NOx levels in the MIR, MOIR, and EBIR scenarios are 

adjusted separately for each mechanisms to yield the corresponding reactivity characteristics, while 

Figure 17a shows the differences when the NOx levels are not adjusted, i.e., when the SAPRC-99 MIR, 

MOIR or EBIR NOx levels are used in the SAPRC-07 calculations. (The NOx levels, and therefore the 

mechanisms differences, are the same in the base case calculations shown on both plots.) It can be seen 

that if the NOx levels are adjusted to yield the same reactivity conditions, the changes in O3 predictions 

resulting from the mechanism update varies from scenario to scenario, ranging from a ~10% increase to a 

~5% increase, though for most scenarios the update causes a decrease in predicted O3, by about 5% on 

average. For a given type of scenario the decrease tends to be correlated with the ROG/NOx ratio, with 

the decrease being largest at the lowest ROG/NOx ratios. 

However, the mechanism change caused a ~5 - ~15% decrease in the NOx levels that yielded 

MIR, MOIR, or EBIR levels, so the results shown on Figure 17a do not reflect the same NOx levels. If 

the NOx levels are held constant, the changes caused by the update have a much more consistent 

dependence on ROG/NOx ratio, and also larger changes for the MIR scenarios and smaller changes for 

the EBIR scenarios. This is consistent with the fact that O3 sensitivities to mechanism differences are 

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0 10 20 30 40

ROG Input (millimoles C/m2)

Maximum

O3 (ppm) (S

A

P

R

C-07)

Base

MIR

MOIR

EBIR

Avg. Cond
105

Figure 17. Change in maximum O3 concentrations in the scenarios used for reactivity assessment, 

calculated using SAPRC-07 compared to SAPRC-99.

greatest at the lowest ROG/NOx ratios (e.g., MIR), and simulations become much less sensitive as the 

higher ROG/NOx ratios (EBIR). O3 reductions of up to ~20% are seen for the MIR scenarios with the 

lowest ROG/NOx ratios, while the changes for most of the EBIR scenarios are less than 5%. 

Updated Ozone Reactivity Scales

Table B-1 in Appendix B gives the results of the MIR, MOIR, EBIR, and average base case 

reactivity scale calculation for all the VOCs currently represented in this version of the mechanism. This 

includes a total of 1029 types of VOCs, of which 722 have explicit mechanism assignments and the 

remainder are represented using the "lumped molecule" approach, and a total of 52 complex mixtures. 

(The latter include the 32 complex mixtures used in previous reactivity tabulations, using the same 

compositions as employed previously [Carter, 2000a and references therein, Carter et al, 1997e, 2000a, 

2000e; Carter and Malkina, 2005, 2007], plus new or revised unspeciated alkane and aromatic mixture 

categories. The Unspeciated alkane mixtures assuming equal amounts of normal, branched, and cyclic 

alkanes1, and unspeciated aromatic mixtures derived as discussed by Carter and Malkina [2005].) The 

table indicates whether the VOC is represented explicitly, and if so whether its reactivity was calculated 

using adjusted product mechanisms, whether the VOC was represented using the lumped molecule 

method, or whether the reactivities are given for complex mixtures. Molecular weights, carbon numbers, 

and (where applicable) CAS numbers are also given in the table.

The incremental reactivities in the MIR scale are of greatest interest because this is the scale that 

is most often used or proposed for use in regulatory and other applications. Figure 18 shows a plot of the 

 

1 This differs from previous tabulations where the unspeciated alkane mixtures had the normal alkanes 

excluded, on the theory that they could be identified in GC analyses. Therefore, the new unspeciated 

categories are appropriate mainly for when no analytical data are available. If analytical data are 

available, the correspond BR-Cnn and CYC-Cnn should be used for the corresponding unspeciated and 

cyclic alkane constituents, with equal amounts being used if the cyclic vs. branched ratio is unknown. 

(a) MIR, MOIR, EBIR NOx Adjusted (b) MIR, MOIR, EBIR NOx same as SAPRC-99

ROG / NOx Ratio

-20%

-15%

-10%

-5%

0%

5%

0 4 8 12

Base

MIR

MOIR

EBIR

Avg. Cond

-20%

-15%

-10%

-5%

0%

5%

0 4 8 12

Change in Maximum

O3

(S

A

P

R

C-07 - S

A

P

R

C99)/S

A

P

R

C-99
106

incremental reactivities in the updated scale against those in the latest SAPRC-99 scale provided by 

Carter (2003a). The 1:1 and 30% lines are also shown. The average change (excluding the 13 outliers 

where the change was greater than 50%) in the MIR's was -8%, and the average absolute magnitude of the 

change (again excluding the outliers) was 11%. The change was less than 30% for approximately 96% of 

these VOCs. The MIR for the base ROG mixture, which is used as the standard for relative reactivity 

scales, decreased by about 3%. If this is taken into account, the average change in relative MIR values 

would be approximately -5%, excluding the outliers.

The compounds whose incremental reactivities in the MIR scale changed by more than 30% are 

listed in Table 25. The table also indicates the probable reasons for the changes for those with the greatest 

changes. Excluding 3-methoxy-1-butanol, where the SAPRC-99 mechanism had a factor of 10 error in the 

OH rate constant, the greatest changes were for halogenated compounds because of the higher estimated 

photolysis rates for the chloroaldehyde and chloroketone products predicted to be formed, and for amines, 

for which new mechanisms were derived based on new chamber data by Carter (2008a).

Updated Uncertainty Estimates

The reactivity tabulation in Table B-1 in Appendix B gives updated uncertainty classifications for 

the various types of VOCs and other information that may be useful in this regard. This includes an 

indication of the availability of environmental chamber data to evaluate the mechanism for the compound, 

and the comprehensiveness of the data for this purpose, and also estimates of likely biases in the reactivity 

estimates, if known. The uncertainty and other codes that are used for this purpose are given and 

described in footnotes to Table B-1.

Figure 18. Plots of incremental reactivities in the MIR scale computed using the updated mechanism 

against those reported previously by Carter (2003a).

-5

0

5

10

15

20

-5 0 5 10 15 20

SAPRC-99

S

A

P

R

C-0

7

Represented Compounds

1:1 and +/- 30% lines

Base ROG Mixture

Incremental Reactivity

in MIR Scale

(gm O3 / gm VOC)
107

Table 25. List of compounds and mixtures whose reactivities in the MIR scale changed by more 

than 30%.

Compound MIR (gm O3 / gm VOC) Probable 

Old New Change Reason [a]

3-Methoxy-1-butanol 0.97 3.87 300% 1

2-(Chloromethyl)-3-chloropropene 3.13 7.00 123% 2

1,2-Dibromoethane 0.046 0.102 119% 3

1,2-Dichloroethane 0.098 0.21 119% 2

trans-1,2-Dichloroethene 0.81 1.70 110% 2

2-Amino-2-methyl-1-propanol 4.75 0.25 -95% 4

Dimethyl amine 9.37 3.17 -66% 4

Mesityl oxide (2-methyl-2-penten-4-one) 17.37 6.51 -63% 5

3,5,5-trimethyl-2-cyclohexenone 10.58 4.63 -56% 5

Propionic acid 0.79 1.22 55%

Triethanolamine 2.75 4.21 53% 4

2,4-Toluene diisocyanate -0.133 -0.065 -52%

Phenol 1.82 2.76 51% 6

1,1,2-Trichloroethane 0.058 0.086 48% 4

Furan 16.54 9.15 -45% 7

2-Methyl-2,4-pentanediol 1.03 1.45 41%

CARB Hydrocarbon Bin 5 2.56 1.56 -39% 8

Diethanol amine 4.05 2.47 -39% 4

p-Xylene 4.24 5.84 38%

Dichloromethane 0.066 0.041 -37%

Chloroform 0.034 0.022 -37%

Acetic acid 0.50 0.68 37%

CARB Hydrocarbon Bin 20 1.49 0.95 -37% 8

n-butyl bromide 0.60 0.82 36%

1,1,1-trichloroethane 0.00 0.00 35%

CARB Hydrocarbon Bin 3 2.52 1.63 -35% 8

1,2-Propylene glycol diacetate 0.94 0.61 -35%

CARB Hydrocarbon Bin 4 2.24 1.47 -35% 8

p-diethyl benzene 3.36 4.43 32%

CARB Hydrocarbon Bin 1 2.08 1.42 -32% 8

1,1-Dichloroethane 0.101 0.069 -31%

[a] Discussion of probable reasons for MIR change:

1 The OH radical rate constant used in SAPRC-99 was found to be low by a factor of 10.

2 Chlorinated aldehyde and ketone products are now assumed to be much more photoreactive.

3 The approximate method used to represent bromine-containing compounds was changed. 

SAPRC-99 used a highly approximate “placeholder” mechanism. SAPRC-07 represents them 

using the mechanism for the corresponding Cl-containing compound.

4 New amine mechanisms developed. Note that amines without hydrogens on groups adjacent to 

amino groups are now estimated to be inhibitors, though their MIR values are still positive 

because of their NOx removal characteristics. Note also that the magnitudes of the amine MIRs 

could be significantly lower if loss of amines by reaction with HNO3 is important. See Carter 

(2008a).
Table 25 (continued)

108

5 These compounds are now represented by the model species used to represent the lumped C5

isoprene product IPRD. The estimated mechanisms used in SAPRC-99, derived using the 

mechanism generation system, are now considered to be too uncertain to use.

6 Phenol is lumped with Cresols in SAPRC-07 but was represented explicitly in SAPRC-99. 

However, the change in MIR is well within the relatively large uncertainty of the mechanism.

7 Furan is now represented explicitly. Previously it was represented by m-xylene using the lumped 

molecule method.

8 The "old" value is from Kwok et al (2000), and were derived from correlations between MIR 

values and boiling points for various types of compounds. The "new" values are calculated using 

compositions derived from various compounds as discussed by Carter and Malkina (2005). Some 

of the differences may be due to the change in methodology, though for most bins Carter and 

Malkina (2005) did not notice large differences between MIRs calculated using SAPRC-99.

It is important to recognize that the uncertainty and bias estimates given on Table B-1 are entirely 

subjective, and not based on any comprehensive sensitivity and uncertainty analysis. This also does not 

take into the account that reactivities of some VOCs may be sensitive to environmental conditions or 

changes in the base mechanism, and may change if the base mechanism or scenarios are updated even if 

the mechanism for the VOC itself is unchanged. An analysis of such would clearly be useful.
109

SUMMARY AND RECOMMENDATIONS

This project was successful in accomplishing most of its objectives, particularly the primary 

objective of developing a complete update to the SAPRC-99 mechanism that represents the current state 

of the science. However, some of the objectives of this project could not be accomplished or completed in 

the time frame for this project, and addressing these objectives need to be included among our 

recommendations for future research. In this section, we summarize the major accomplishments of this 

project and the results and conclusions that were obtained, followed by a summary of the objectives that 

could not be fully accomplished and our recommendations for future research.

Summary of Project Accomplishments

The major accomplishment of this project is the development of the SAPRC-07 chemical 

mechanism and its associated reactivity scales that are documented in this report. Specific 

accomplishments, results, and conclusions of this project are summarized as follows.

Rate constants updated. All the rate constants in the mechanism have been reviewed based on 

results of current evaluations, and updated as needed. This includes updates to the absorption crosssections and quantum yields for the photolysis reactions, where appropriate. The most recent IUPAC 

(2006) and NASA (2006) evaluations were used as the primary basis for updating the rate constants in the 

base mechanism and common organic products, the evaluations of Calvert et al (2000, 2002) were used 

for reactions relevant to alkenes (Calvert et al, 2002) and aromatics (Calvert et al, 2000), and the recent 

evaluations of Atkinson (1997), Atkinson and Arey (2003) and Calvert et al (2000, 2002) were used for 

rate constants for individual VOCs. Other sources, including recent work in our laboratory on reactivity 

studies of specific compounds, were used as appropriate.

Most of the rate constant changes were relatively small, but a few errors were found and

corrected and some potentially significant changes occurred. Various uncertainty and sensitivity studies 

indicate that the rate constant for the OH + NO2 reaction is particularly important, and based on the 

results of the recent NASA (2006) evaluation, the rate constant for ground-level conditions increased by 

~18%. This could result in somewhat lower O3 predictions under some conditions (as indicated by results 

of box model simulations of ambient scenarios, discussed below), and probably contributed to the need to 

re-adjust uncertain parameters in mechanisms for some individual VOCs to be consistent with chamber 

data, as indicated below. Photolysis rates for some aromatic and isoprene oxidation products were 

increased by ~40% or more. The effects on the aromatics mechanism are compensated by other changes 

in the aromatics mechanisms, but the changes for isoprene may have an impact on airshed simulations, 

though the model performance in simulating available isoprene chamber data was not affected. However, 

the effects of the many changes that were made, taken as a whole, have not been fully assessed, other than 

the limited number of box model simulations carried out in conjunction with updating the reactivity scale.

Aromatics mechanisms reformulated. The mechanisms for the aromatic ring fragmentation 

reactions were reformulated to be more consistent with estimated explicit mechanisms that were derived 

as part of this project and to give predictions that are somewhat more consistent with "direct reactivity" 

results reported by Carter and Malkina (2002). These mechanisms incorporate much of the new 

information contained in the review of Calvert et al (2000), particularly in the representation of the ring

opening products. However, although not as simplified and parameterized as the aromatic representation 

used in SAPRC-99, the updated mechanisms are still highly simplified in many respects, and are not 

consistent with all of the available data given by Calvert et al (2000) and others, and some of the 

inconsistencies with available environmental chamber data still persist.

The approach that was initially employed was to develop explicit versions of the mechanisms for 

representative aromatic hydrocarbons, and use these to derive more condensed, but chemically 
110

reasonable, versions for airshed model calculations. Unfortunately, because of time constraints and other 

problems, the effort to develop explicit mechanisms that could account for reactivity differences among 

aromatic isomers could not be completed within the time frame available to this project. However, the 

explicit mechanisms were developed to the point where they did serve as the basis for the more 

condensed aromatics mechanism that is described in this report. The aromatic mechanism formulation 

developed for this project, though simplified in some respects, represents a much closer approximation to 

the explicit mechanisms than SAPRC-99, and serves a useful basis for future improvements in this area.

As part of this effort, environmental chamber experiments were carried out with several furans, 

which were studied because these compounds are expected to form the same type of highly photoreactive 

fragmentation products as formed in the ring opening reactions of the alkylbenzenes, only in higher yields 

and without the complication of uncertain competing processes. Because the development of the explicit 

aromatics mechanisms based on these data could not be completed, the results of these experiments could 

not be incorporated in the final versions of the aromatics mechanisms developed for this work, other than 

in the mechanisms for the furans themselves. However, these data should be useful in future explicit 

aromatics mechanism development efforts. This explicit mechanism development effort, and the 

experiments carried out to support it, will be discussed in more detail in future reports.

Chlorine chemistry added. The representation of chlorine chemistry has been added to the 

mechanism as an optional capability. The inorganic ClOx and Cl atom reactions with common organic 

products have been added as an optional module of the base mechanism, and mechanisms for chlorine 

atom reactions were derived for all the explicit and lumped VOCs used in the version of the mechanism 

for ambient simulations and in the mechanisms used to calculate reactivities of individual chlorinated 

VOCs. The chlorine chemistry mechanisms were based primarily on the recent IUPAC (2006) and NASA 

(2006) evaluations, various evaluations and studies of VOC + chlorine reactions, results obtained in our 

previous studies of chloropicrin (Carter et al, 1997a) and dichloropropenes (Carter and Malkina, 2007), 

and also various estimation methods that were developed as part of this project.

In addition to improving the ability of airshed models to simulate air quality in regions impacted 

by chlorine emissions, the representation of chlorine chemistry and associated updates has resulted in 

improved reactivity estimates for a number of VOCs of interest in California, including the pesticides 

chloropicrin and dichloropropenes (Carter and Malkina, 2007), and reduced uncertainties in reactivity 

estimates for chlorinated compounds in general.

Mechanism generation system enhanced. The mechanism estimation and generation system is an 

important component of SAPRC-99 that was used to generate fully explicit mechanisms for most of the 

non-aromatic VOCs, from which the more condensed mechanisms used in the model were derived. This 

system was enhanced in a number of respects for this project. Updated rate constants for the primary 

reactions of the individual VOCs with OH, O3, NO3, and O

3

P were incorporated in the system. The 

capability of estimating and generating mechanisms for reactions of VOCs with chlorine atoms was 

added. The types of compounds and radicals whose reactions could be generated using the system was 

added to include to include species with more than one ring (e.g., terpenes), species with more than one 

double bond, alkynes, and (to a limited extent) aromatics and unsaturated aromatic ring opening products. 

This was used to assist in the derivation of mechanisms for compounds that could not be processed 

previously, and was also useful in deriving portions of the updated aromatics and aromatic products 

mechanisms.

Capability for adaptation to SOA predictions improved. Mechanisms for predictions of PM 

require an appropriate representation of the formation of the low volatility products that contribute to 

SOA, and how they depend on reactant conditions such as availability of NOx. Recent environmental 

chamber studies (Odum et al, 1996, Hurley et al, 2001, Sato et al, 2004a, Presto et al, 2005, Doherty et al, 

2005, Song et al, 2005) indicate that SOA formation can change significantly with VOC/NOx ratios. This 

is attributed to competing branching ratios in reactions of peroxy radicals with NOx, HO2, and other 
111

peroxy radicals. Hydroperoxides formed in the reactions of peroxy radicals with HO2 appear to be 

particularly important in this regard. Unfortunately, the SAPRC-90 through SAPRC-99 mechanisms, like 

CB4 and CB05, uses a chemical operator lumping approach to represent peroxy radical reactions that 

requires representing hydroperoxide formation in a highly condensed and approximate manner. This is 

because explicitly representing all the possible peroxy + peroxy reactions that may occur under low NOx

conditions requires an excessive number of reactions to represent processes that are unimportant to ozone 

formation, and the SAPRC-90/CB4 chemical operator lumping approach results in a large reduction in 

mechanism size without significantly impacting predictions of O3 and formation of organic product 

species that are important when ozone formation occurs. However, this is not as satisfactory an 

approximation when the model is being used to predict formation of secondary PM.

Appropriately representing hydroperoxide formation under low NOx conditions, and using 

separate species to represent low-volatility hydroperoxides, requires that a different method be used to 

represent peroxy radical reactions. An explicit approach, such as used in the MCM (Jenkin et al, 2003; 

Saunders et al, 2003), or a semi-explicit approach such as used in RADM-2 (Stockwell et al, 1990) or 

RACM (Stockwell et al, 1997) mechanisms, would be satisfactory in this respect, but it requires adding a 

significant number of species and reactions to the mechanism, and is not compatible with the lumped 

parameter approach used in the SAPRC mechanisms to derived mechanisms for lumped species based on 

the mixtures of compounds they represent (Carter, 1990, 2000a, 2000b; Adleman et al, 2005). A more 

computationally efficient approach would be desirable for most comprehensive modeling applications.

The SAPRC-07 mechanism developed for this project addresses these problems by implementing

an alternative chemical operator approach for peroxy radicals reactions that involves adding a much 

smaller number of species and reactions to the mechanism, and is compatible with the SAPRC lumped 

parameter methods and software that has already been developed. With this method, hydroperoxide 

formation can be represented more explicitly, with separate lumped species formed from different 

compounds based on considerations such as reactivity and volatility. It also permits separate 

representation of organic nitrates formed in peroxy + NO reactions based on reactivity and volatility 

considerations, which was also difficult under the formulation used in SAPRC-99 and CB4/05.

Because development and evaluating a mechanism for prediction of SOA precursors is a major 

project that was well beyond the scope of this project, the initial version of SAPRC-07 does not fully take 

advantage of the enhanced capabilities of this mechanism to represent formation of SOA precursors. It

does include a separate model species to represent the low volatility hydroperoxides formed from 

aromatics, primarily as a means to illustrate this capability, but its ability to predict SOA chamber 

experiments has not yet been evaluated. However, this version serves as a useful starting point in this 

regard, and can be used in a much more straightforward way to develop models that more accurately 

predict how SOA formation varies with conditions of NOx availability.

Mechanisms for many types of VOCs added or improved. A major feature of the SAPRC 

mechanisms is the ability to separately represent the many hundreds of types of VOCs for reactivity 

assessments, toxics modeling or other applications, and for deriving condensed mechanisms tailored for 

the specific mixtures of compounds that are present. The rate constants and mechanisms for the VOCs 

represented in SAPRC-99 were updated for this project, and in some cases improvements were made for 

VOCs previously represented using more approximate methods. The number of types of VOCs with 

distinct mechanisms was increased by 23% from 585 to approximately 720, and the total number of VOC 

classes for which reactivity estimates could be derived (whether by explicit representation or using the 

"lumped molecule" approach1) was increased by 22% from 873 to over 1050. Most of the increases in 

distinct mechanisms are for alkanes, alkenes, and oxygenates found in emissions inventories, whose 

mechanisms could be readily derived using the mechanism generation system, but also an increased 

 

1

In the lumped molecule approach, the compound is represented by assuming it has the same impact, on a 

per-molecule basis, as another compound or mixture of compounds assumed to have similar reactivities.
112

number of mechanisms were derived for more appropriate representation of the higher alkylbenzenes1. 

Improved mechanisms are incorporated for halogenated compounds incorporating chlorine chemistry as 

discussed above, though most of these need to be experimentally evaluated. A few errors were found in 

SAPRC-99 mechanism assignments that were corrected, the most significant being a factor of 10 error in 

the rate constant for 3-methoxy-1-butanol.

Although mechanisms and representations were changed for a large number of the compounds, 

the number of compounds with significant MIR changes was relatively limited. The MIR changes were 

less than 25% for 95% of the chemical classes, and only 12 compounds had changes of more than 50%. 

However, some compounds whose MIRs were not previously listed have regulatory reactivities estimated 

using only "upper limit" methods (Appendix D in Carter, 2000a), so the addition of new compounds to 

the reactivity list may in some cases result in significantly different reactivities for regulatory 

applications.

Updated mechanism evaluated against chamber experiments. The updated mechanism was 

comprehensively evaluated by comparing predictions with results of all environmental chamber 

experiments used for SAPRC-99 evaluation, plus the results of more recent UCR experiments, and also 

the TVA chamber experiments used by Carter (2004), the UNC experiments used in the RADM2, and 

SAPRC-90 evaluations of Carter and Lurmann (1990, 1991). The results of this evaluation can be 

summarized as follows:

For some compounds it was found that re-adjustments to some of the uncertain mechanistic 

parameters had to be made to obtain mechanism performance comparable to SAPRC-99. This is 

apparently because changes to the base mechanism resulted in changes in parameter values that gave best 

fits to the data. This included primarily re-adjustments to overall nitrate yields in peroxy + NO reactions 

for VOCs where these are uncertain, but also the radical yields in some ozone + alkene reactions could be 

increased to values that are somewhat more consistent with, but still lower than, results of laboratory 

studies of these reactions (e.g., see Carter, 2000a, Pinho et al, 2006). These adjustments were incorporated 

in the updated mechanism.

In general, the model performance of the updated mechanism in simulating experiments for 

individual compounds or types of VOCs was comparable to that for SAPRC-99, with the overall bias for 

all single compound experiments, taken as a whole, being very low. Although major changes were made 

to the aromatics mechanism, the model performance in simulating the single aromatic and aromatic 

reactivity experiments did not change significantly. This can be attributed to the fact that for both 

SAPRC-99 and SAPRC-07, the yields or (in the case of SAPRC-07) effective quantum yields of 

photoreactive aromatic ring-fragmentation products were adjusted to optimize fits to the data. However, 

the updated mechanism did perform somewhat better in simulating direct reactivity data or effects of 

added CO (Carter and Malkina, 2002; Carter, 2004), though the results were still not completely 

satisfactory.

The model performance for simulating data for some types of compounds changed even though 

no changes were made to their mechanisms. Biases that were previously seen in model simulations in 

propylene and ethylene glycol (Carter et al, 2005a) and synthetic isoparaffinic mixtures (Carter and 

Malkina, 2005) were significantly reduced. On the other hand, slightly increased positive biases were 

seen in simulations of effects for some types of compounds, such as the larger n-alkanes, on maximum O3

yields in lower NOx conditions. These results indicate that O3 reactivity predictions, at least for chamber 

 

1

In SAPRC-99, the higher alkylbenzenes are represented using mechanisms derived for the 

methylbenzenes. The updated mechanism has separate model species that incorporates the increased rate 

constants for reaction on the larger alkyl substituents of the aromatic ring, higher estimated nitrate yields, 

and reactivity differences for o-, m-, p-, and 1,2,3-, 1,2,4-, and 1,3,5-isomers.
113

experiments, can be sensitive to changes in the base mechanism even if the mechanism of the VOC is not 

changed.

One area of potential concern is that the mechanism update caused a slight increase in overall 

biases in model simulations of experiments with mixtures of VOCs, including those designed to simulate 

ambient conditions. For all such experiments, the average bias in the simulations of the O3 formation and 

NO oxidation rates in the second hour of the experiments increased from 5% to 12%, and the biases in 

simulations of final O3 formed and NO oxidized increased from 3% to 6%. However, when examining 

run types separately, one sees the biases vary with type of experiment, with some types of experiments 

having greater positive biases and some having greater negative biases, compared to SAPRC-99. These 

changes are small compared to the 30% variability of the fits overall, but because of the large number of 

such experiments (>1500 total) it may be statistically significant.

The mechanism update also did not solve the problem, noted by Carter (2004) and Carter et al 

(2005b) that SAPRC-99 had a consistent bias in underpredicting rates of O3 formation and NO oxidation 

in surrogate - NOx experiments carried out at relatively low NOx levels in the new UCR EPA chamber, 

with the bias decreasing at higher ROG/NOx ratios. This bias still exists with the updated mechanism, 

with the dependence of ROG/NOx ratios being approximately the same. It is interesting to note that the 

dependence of the bias on ROG/NOx in experiments in this chamber is in the opposite direction when the 

aromatics are removed from the surrogate, suggesting that the problem may be related to the aromatics 

mechanism, both for SAPRC-99 and SAPRC-07.

Mechanism implementation. The mechanism developed in this project was implemented for the 

box model calculations used for reactivity scale calculations, and the data files used in this 

implementation can serve as the basis for implementing in more comprehensive airshed models such as 

CMAQ or CAMx. Although there was insufficient time and resources remaining in this project to adapt 

the updated mechanism into such a model, the necessary data files and associated implementation 

documentation are being made available at the project web site at http://www.cert.ucr.edu/~carter/ 

SAPRC. The types of data and files formats provided are similar to those used when distributing SAPRC99, which has been successfully implemented into various models. However, we will continue to provide 

guidance to modelers in implementing this mechanism, as needed.

An important part of mechanism implementation is providing assignments of the many chemical 

categories used in speciation profiles for emissions inventories to the model species used in the 

mechanism. As part of this project, the emissions speciation database previously developed to provide a 

comprehensive and consistent speciation approach for the SAPRC-99, RADM2, CB4, and CB05 were 

updated to include SAPRC-07 as one of the optional mechanisms (Carter, 2008b). At present, only the 

fixed-parameter version of SAPRC-07 is implemented. Work on updating the system for the variable 

parameter version is planned, and when completed will be made available at the SAPRC mechanism web 

site noted above.

Reactivity scales updated. The updated mechanism developed for this project was used to 

calculate MIR and other reactivity scales for all the ~780 types of VOCs for which reactivities values 

were provided on the most recent SAPRC-99 update (Carter, 2003a), plus ~285 additional types of VOCs 

that have been added as part of this update. Uncertainty classifications were also updated as part of this 

work, and an additional code, indicating the estimated likely bias of the reactivity value (if known) was 

added. Although as indicated above the number of VOCs for which large changes in MIR values is 

relatively limited, the MIR values changed by more than 5% for a majority (56%) of the VOCs whose 

MIRs were tabulated previously. It is recommended that these be used to supercede the reactivity values 

distributed previously (Carter, 2000a, 2003a).

Preliminary assessment of impacts of updates on predictions of ambient ozone. Although this 

mechanism has not yet been implemented in comprehensive airshed models, the results of the box model

simulations carried out in conjunction with the reactivity scale update provides some indication of how 
114

the mechanism update may affect predictions of ambient ozone. These are one-day of 39 simplified 

EKMA model scenarios designed to represent O3 formation in 39 areas in the United States in the late 

'80's (Baugues, 1990), with NOx levels adjusted to represent various conditions of relative NOx

availability that are relevant to VOC reactivity (Carter, 1994a). The results indicate that the mechanism 

update causes changes in maximum ozone concentrations ranging from a ~10% decrease to a ~5% 

increase, with the predicted O3 decreasing by about 5% on average. For a given type of scenario, the 

decrease tends to be correlated with the ROG/NOx ratio, with the decrease being largest at the lowest 

ROG/NOx ratios. However, this is not necessarily the case if the NOx levels are varied with the other 

scenario conditions held constant, which means that the ROG/NOx ratio is not the only factor determining

how the mechanism update changes predictions of O3 formation in ambient scenarios. 

Overall, this suggests that it is more likely than not that the mechanism updates will cause slight 

decreases in predicted ambient O3, though this may not be true for all areas or scenarios. However, the 

box models used in the reactivity assessment calculations are highly simplified representations of ambient 

conditions, and comprehensive models are needed to fully assess the impacts of this update on ambient O3

predictions, and also on predictions of effects of control strategies. 

Recommendations

Although the accomplishments of this project were significant, there were some objectives of this 

project that could not be met within the time and resource constraints available for this project, and there 

areas where work is needed that were beyond the scope of the project as proposed. These objectives are 

still important, so the first recommendation resulting from this project is that work be carried out to 

address these objectives. These and other recommendations are summarized below.

Aromatics Mechanisms. Although the reformulated aromatics mechanisms developed in this 

work represent an improvement over SAPRC-99 in terms of representation of the actual chemistry 

expected to be involved, they still contain significant simplifications and approximations, and are not 

fully consistent with all recent laboratory results. A considerable effort was expended in this project in an 

attempt to develop explicit or near-explicit mechanisms that could predict reactivity differences in 

aromatic isomers (such as indicated in the chamber data of Carter et al, 1997a), but because of time 

constraints this could not be completed, and the preliminary explicit mechanisms were used as a basis for 

generalized mechanisms for aromatics that is incorporated in the current SAPRC-07. This explicit 

mechanism development work, and the environmental chamber experiments with furan carried out to 

support this effort, will be described in more detail in future reports once more progress can be made in 

this area.

As indicated above, the reformulated aromatics mechanisms gave somewhat improved 

performance in simulating the direct reactivity results of Carter and Malkina (2002), and also somewhat 

improved performance in simulating the effects of CO when added to aromatic - NOx experiments 

(Carter, 2004). However, the performance, though improved, was still not entirely satisfactory in these 

regards, since direct reactivity was still somewhat overpredicted, and the effects of CO addition was still 

underpredicted. In addition, the problem of underpredicting O3 at low ROG/NOx ratios and low NOx

levels (as noted by Carter, 2004), which is attributed to problems with the aromatics mechanisms, has not 

been resolved. Therefore, although progress has been made, work on the aromatics mechanisms is still 

needed.

Chlorine and Other Halogen Mechanisms. Significant progress was made in improving the 

representation of chlorine chemistry and chlorine-containing compounds, but more work is needed in this 

area. Because of limitations in the mechanism generation system's ability to estimate reactions of 

chlorine-containing alkoxy radicals, the system could not derive complete mechanisms for the reactions 

of chlorine atoms for the alkenes without having to make explicit assignments for these radicals as 

required. Because this is a time-consuming process, chlorine mechanisms could only be derived for the 
115

most important or representative alkenes, with the mechanisms for the others being approximated based 

on these results. This is probably not a major problem for most airshed and reactivity calculations, but is a 

limitation of the present system.

A more significant problem is the fact that mechanism evaluation and reactivity data is available 

for only a limited number of chlorinated compounds, and the limited data that exist suggest that halogencontaining oxygenated products of these compounds may be considerably more reactive than the model 

species used to represent the oxygenated products of the unhalogenated compounds (see, for example, 

Carter and Malkina, 2007). Although the data for chloropicrin and the 1,3-dichloropropenes (Carter and 

Malkina, 2007) are reasonably well simulated by the current mechanism, the simulations of the 

experiments with trichloroethylene (Carter et al, 1996a) are not as satisfactory in some respects. 

Therefore, more data and mechanism development work is needed on individual chlorinated compounds 

and their oxidation products.

A similar effort is needed for adding bromine chemistry and reducing uncertainties in reactivity 

estimated for bromine- or iodine-containing compounds, but this was beyond the scope of this project. 

Such compounds are also present in emissions inventories, and bromine or iodine chemistry may need to 

be represented in some ambient scenarios. The few bromine-containing compounds representing in the 

current mechanism are approximately represented using the mechanisms for the corresponding chlorinecontaining compounds, but the biases introduced by this representation are highly uncertain, and iodinecontaining compounds are not currently represented in this mechanism.1 Work in this area is needed if 

these compounds, or non-chlorine halogen chemistry, are determined to be important.

Mechanisms for Amines. Although estimated mechanisms for amines were developed and to 

some extent evaluated as part of the study of Carter (2008a), significant uncertainties remain concerning 

their atmospheric ozone impacts. The largest uncertainty concerns the extent to which emitted amines are 

available for atmospheric reaction, and which is removed from the gas phase due to gas-phase reaction 

with HNO3 or to heterogeneous processes. Atmospheric reactivity estimates vary by over an order of 

magnitude depending on what assumptions are made concerning removal by reaction with HNO3. The 

current reactivity values for amines are based on assuming that removal by reaction with HNO3 is not 

important, in order to obtain upper limit magnitude ozone impact estimates. But use of these upper limit 

magnitude estimates may not be appropriate for all regulatory applications. The current mechanisms also 

do not correctly predict the effects of reactive amines on O3 formation under low NOx conditions, even if 

the amount present is adjusted to optimize model fits to initial rates of NO oxidation and O3 formation. 

However, that uncertainty probably does not affect MIR predictions. Therefore, the amines mechanisms 

given here are much more uncertain than those given for most other VOCs, and more data, with improved

analytical methods, and better characterization of sources and sinks of HNO3 and amine salts in the 

atmosphere, are needed to reduce uncertainties for mechanisms and ozone impact estimates for amines.

Mechanism Generation System. As discussed by Carter (2000a), the mechanism generation 

system incorporates a large number of estimation methods for alkoxy, peroxy, and other radical reactions 

that serve as the basis for the full oxidation mechanisms that are derived. These are based on various 

estimation methods and a large body of data for individual reactions that were available up to the time 

SAPRC-99 was developed. Although an objective of this project was to update these radical reaction 

estimation methods based on any new data or theories that may have become available since then, 

because of time constraints we were unable to carry out these updates as part of this project. Although 

there is no indication that significant changes or updates to this system are needed, and in general the 

system has performed reasonably well for the types of compounds it is designed to represent, the 

predictions of the system is an integral part of the current SAPRC mechanisms, and updating its 

assignments should be included as part of the next comprehensive mechanism update effort.

 

1 Work on methyl iodide is being carried out under separate funding, and a mechanism for this compound 

and iodine species may be included in a future update. 
116

As indicated above, the lack of estimation assignments for reactions of halogenated radicals 

makes generation of most chlorine + alkene reactions difficult, and methods for estimating more of such 

reactions need to be implemented to permit full incorporation of chlorine chemistry for unsaturated 

VOCs. Estimation assignments, or heat of formation estimates needed to support the existing estimation 

methods, are also lacking or unreliable for many types of radicals formed in aromatic systems or other 

systems with multiple double bonds, limiting the utility of the system for development of explicit 

mechanisms for aromatics. Although progress was made in this project to adapt this system to be more 

useful in mechanism development for such compounds, it has not yet evolved to the point where it can 

used to derive complete or reliable mechanisms for actual implementation in airshed models. Further 

work in this area, and expanding its capabilities to other types of compounds, would clearly be useful, and 

ultimately aid mechanism development and reactivity estimates for a wider variety of VOCs than 

currently possible.

Adaptation to SOA Predictions. As discussed above, the initial version of SAPRC-07 

documented in this report does not fully take advantage of the enhanced capabilities of this mechanism to 

represent formation of low volatility SOA precursors and how they depend on NOx conditions. Work in 

this area is clearly the next step in developing improved models for secondary PM formation that can 

predict how PM formation varies with chemical conditions. Although the chemistry and physics of SOA 

formation is complex and much long-term research is needed, significant advances can be made in the 

short term to enhance SAPRC-07, and its associated mechanism generation system, to take better 

advantage of the capability of this mechanism for SOA predictions. This could include the following.

 Adding new lumped organic product model species to represent compounds of low volatility. 

This would include new model species for low volatility hydroperoxides (besides those formed 

from aromatics) and organic nitrates, as well as those formed in the oxidations in the presence of 

NOx such as those represented in current PM models 

 Implementing methods to estimate product volatility based on structure in the mechanism 

generation system, and using these to lump the products formed in the fully explicit generated 

mechanisms into the appropriate low volatility model species. In principle, this would result in 

generations of mechanisms for predicting SOA as well as O3 reactivity.

 Evaluating the enhanced mechanisms' predictions of SOA using available environmental chamber 

data where PM measurement data are available. There is an increasing body of environmental 

chamber data suitable for this purpose, being generated at our laboratories and elsewhere that can 

be used for this purpose.

 Conducting environmental chamber experiments with PM measurements suitable for testing

predictions of the enhanced mechanism that cannot be evaluated with available data. A priority 

would be to evaluate the predictive capability of the mechanism generation system in this regard, 

and to determine which parameterization and volatility lumping approaches are most consistent 

with the data for the widest variety of compounds.

The current mechanism does include a separate model species to represent the low volatility 

hydroperoxides formed from aromatics, primarily as a means to illustrate this capability, but its ability to 

predict SOA chamber experiments has not yet been evaluated. However, this version serves as a useful 

starting point in this regard, and will therefore allow a much more straightforward approach to develop 

models that more accurately predict how SOA formation varies with conditions of NOx availability.

Once adapted and evaluated as indicated above, the enhanced PM mechanism would need to be 

implemented in actual airshed models and evaluated against ambient data. It could also serve as a basis 

for deriving SOA reactivity scales for VOCs, should that be of interest in regulatory applications 

(Seinfeld et al, 1999).
117

Mechanism Performance Issues. Although the updated mechanism simulates the available 

environmental chamber database reasonably well, the results of the mechanism evaluation carried out for 

this project indicated several potential problems that need to be investigated. The fact that the mechanism 

update caused slightly increased biases in simulations of experiments with various mixtures is an area of 

concern. The statistical significance of these small biases needs to be assessed, and an analysis of their 

potential sources needs to be carried out. The tendency of the mechanism to underpredict O3 at low 

ROG/NOx ratios is clearly statistically significant, and has not been resolved with this update. The 

experiments with the individual compounds do not clearly point to any specific compound or group of 

compound whose mechanism is causing the problems, and suggest that this is due to some change in the 

base mechanism. A related issue is the fact that changes to the base mechanism have caused changes in 

model performance in simulations of experiments with compounds or mixtures whose mechanisms have 

not changed, with reduced biases for some glycols and isoparaffinic alkane mixtures, and slightly 

increased biases for some other compounds. 

Assessing the mechanism performance issues with mixtures, and the effects of base mechanism 

changes on evaluation results for individual compounds, will probably require more in-depth analysis of 

mechanism behavior than previously has been carried out. Application of existing uncertainty and 

sensitivity analysis and process analysis methods may be useful in this regard, but probably new analysis 

methods will need to be developed. The objective would be to determine what uncertain portions of the 

base mechanisms may be introducing biases in the model evaluations, the extent to which these biases 

may be significant when the mechanism is used in ambient simulations or control strategy assessments, 

whether adjustments of these uncertain areas to reduce these biases may be justifiable, and if so what 

adjustments should be made. This is an area where original research is needed.

Mechanism Evaluation Database. Although the updated mechanism includes what we believe are 

improved estimates for a number of types of VOCs for which no data is available, in many cases the 

reliability of these estimates needs to be experimentally tested. This is particularly true for amines and 

those halogenated compounds for which no environmental chamber reactivity data are available. 

Environmental chamber reactivity studies of representatives of these and other previously unstudied 

chemical classes are needed to reduce uncertainties in their mechanisms and associated reactivity 

estimates. The reactivity tabulations include uncertainty codes indicating those compounds for which 

experimental data are most needed.

Although in general both SAPRC-99 and SAPRC-07 perform reasonably well in simulating 

results of experiments in the various UCR chambers and also the TVA chamber, the performance is not as 

satisfactory in simulating the results of some of the older UNC outdoor chamber experiments used in the 

SAPRC-90 and RADM2 evaluations (Carter and Lurmann, 1990, 1991). This is true in experiments with 

propene, toluene, o-xylene, and a number of mixture runs. On the other hand, the SAPRC mechanisms 

perform reasonably well in simulating results of more recent UNC chamber experiments that were used in 

the evaluation of Carter and Atkinson (1996), suggesting that some of the differences may be reduced if 

more recent datasets were employed. The difference performance in the case of aromatics may be one 

source of difference between the SAPRC and Carbon Bond mechanisms, since the latter relied more 

heavily on the UNC chamber datasets during its development (Gery et al, 1988). This needs to be 

investigated. An improved evaluation of mechanism performance issues, discussed above, may be useful 

in this regard. In the meantime, we believe that characterization uncertainties and background problems 

for the indoor SAPRC and TVA chambers are significantly less than for the earlier UNC chamber 

experiments, and consequently the indoor chamber data are used as the primary means of mechanism 

evaluation.

For many types of compounds, the primary dataset for mechanism evaluation consists of 

incremental reactivity experiments, in which the effect of adding the compound to simplified 

representative ambient mixtures is assessed. This provides the only useful mechanism evaluation dataset 
118

for compounds that are not radical initiators1, and more closely approximates the environments where the 

VOC reacts than other types of experiments. However, model sensitivity calculations indicate that results 

of the currently available types of incremental reactivity experiments are much less sensitive to effects of 

secondary reactions of reactive organic products than is calculated for the atmosphere. This means that 

this aspect of the mechanism is not being adequately evaluated with the available dataset. Calculations 

indicate that experiments with higher overall radical levels, such as experiments with longer reaction 

times, higher light intensities, or various radical sources, are needed to improve mechanism evaluations in 

this respect.

The current dataset of environmental chamber experiments is also not adequate for systematically 

evaluating model predictions of temperature effects on secondary pollutant formation. The UCR-EPA 

chamber is suitable for carrying out such experiments, and in fact the plan for this project included 

conducting a limited number of experiments with temperature varied. However, because of problems with 

the light source, only a limited number of such experiments could be successfully carried out, and the 

conditions are not yet adequately characterized for mechanism evaluation. Additional work in this area is 

still needed.

Mechanism Adaptation. Because the mechanism development and evaluation was not completed 

until well after the project was scheduled for completion, there was insufficient time and resources 

remaining to implement this mechanism in any comprehensive airshed model. This work remains to be 

done, and as indicated above we will assist the model implementers in this regard as needed. This report, 

and the files and additional documentation that are being made available at the SAPRC mechanism web 

site at http://www.cert.ucr.edu/~carter/SAPRC should provide the information needed.

In addition, there was also insufficient time and resources in this project to prepare a condensed 

version of the updated mechanism as discussed in the proposal for this project (Carter, 2003b). Although 

computer capabilities are continuing to increase, for some modeling applications a more condensed, and 

computationally efficient, mechanism may give adequate predictions, and it may be more important to 

apply more of the available computer resources to other modules in the model, or to enhance spatial 

resolution. Therefore, a more condensed version of this updated and evaluated mechanism is still needed. 

Preliminary versions of SAPRC-07 condensed mechanisms have been developed (Carter, 2008c), but 

these mechanisms have not yet been finalized.

In order to derive a condensed mechanism for representing complex mixtures in airshed model 

applications, it is necessary to use a standard "base reactive organic gas (ROG)" mixture to represent the 

mixture of anthropogenic VOCs emitted into ambient atmospheres to derive the parameters for the 

mechanism's lumped model species. Ideally this mixture should be derived for each scenario being 

modeled, and procedures and data files exist for doing this for the SAPRC-99 mechanism (Carter, 2000b, 

Adleman et al, 2005; Carter, 2008b), which will be adapted to the updated mechanism in the future 

(Carter, 2008b). However, in practice modelers have preferred to continue to use the "fixed parameter" 

version of the mechanism, where the parameters for the lumped model species are derived using a 

standard mixture used for this purpose, and incorporated in the mechanism without change. Such a fixed 

parameter mechanism was developed as part of this work.

The updated fixed parameter mechanism developed in this work employed the same standard 

base ROG mixture as used for the fixed-parameter version of SAPRC-99 (Carter, 2000b), which is the 

base ROG mixture used in the original reactivity calculations of Carter (1994a). This mixture was derived 

by Jeffries (1989) from analysis of air quality data of Lonneman (1986), with minor modifications as 

discussed by Carter (1994a,b). Since advances have been made in analytical methods and emissions 

compositions have probably changed since the mid-80's, this mixture is out of date and needs to be 

 

1 Chamber experiments with compounds without significant internal radical sources are dominated by 

uncertain and variable chamber effects unless other reactants are present to provide the radical initiation.
119

updated. However, attempts to obtain a documented updated base ROG mixture from the CARB or EPA 

have been unsuccessful. Once such a mixture becomes available, the fixed parameter version of the 

mechanism should be updated accordingly.

Reactivity Scales Update. The updated reactivity scales developed in this work can be considered 

to represent the state of the science in atmospheric chemistry, though as indicated above there are 

uncertainties and areas where further research is needed. However, updating the scenarios and reactivity 

calculation methodology was beyond the scope of this project, so the same scenarios and methodologies 

were used as employed by Carter (1994a). Evaluations carried out by the Reactivity Research Working 

Group (RRWG) indicate that this methodology could be improved in a number of respects (NARSTO, 

2007), particularly the scenarios and modeling methods. At a minimum the scenarios should be updated 

to represent the range of conditions currently occurring in urban areas, and the derivation of the scenarios 

should be better documented. The mechanism developed in this work can then be used for calculating 

reactivity scales with scenarios and methodology updated as well as the mechanism.

Research Priorities. The priorities for the recommended research discussed above depend on the 

time frame and the priorities of the funding agencies. In terms of use of the mechanism for modeling, the 

highest near-term priorities are adaptation of the mechanism for airshed models, implementing the 

emissions assignments, and developing and adapting the condensed version of the mechanism. This work

is presently unfunded, but is needed before this mechanism can be widely used. In terms of the reactivity 

scales, the highest near-term priority is probably reducing uncertainties concerning availabilities of 

amines to react in the gas phase, assuming that suitable experimental procedures to assess this can be 

developed. Improved reactivity estimates for other classes of compounds may become priorities in the 

near future, but as far as we are aware the amines is the greatest near-term concern for the CARB.

In the medium term the highest priority is probably reducing the uncertainty in the gas-phase 

predictions of the mechanism in general. Even for applications where PM modeling is a priority, one 

needs a mechanism that can appropriately simulate gas-phase processes before it can be expected to 

appropriately simulate formation of secondary PM. In this regard, we recommend that priority be given 

for research aimed as assessing the existing discrepancies between model predictions and chamber data, 

discussed above under the heading "Mechanism Performance Issues," and uncertainty and process 

analyses aimed at relating these performance issues and associated uncertainties to ambient predictions of 

interest. This would aid in the development of effective research agendas for improving mechanism 

performance in priority areas, and obtaining the data (either environmental chamber or basic laboratory 

measurements) most needed to serve this objective.

Regardless of the results of the process or performance analysis, it is clear that the mechanisms 

for aromatics remain an important uncertainty. However, breakthroughs in fundamental studies, perhaps 

using improved analytical methods that actually give reliable quantitative product yields, or development 

of improved theoretical methods that actually have predictive capabilities, are probably needed before 

additional mechanism update work and chamber studies may be useful. Medium and longer term research 

priorities should include support for exploratory methods that might achieve the needed breakthroughs, 

even if there is some risk of failure.

The priority for adaptation of the mechanism for PM modeling depends on the priority to the 

funding agency for predictive modeling of secondary PM and SOA. The CARB should use an integrated 

approach for developing improved mechanisms for gas-phase and PM formation processes, and building 

on the mechanism development effort they supported for ozone modeling, as discussed above under the 

heading "Adaptation to SOA Predictions" would be consistent with this approach. If the CARB decides 

instead to use another mechanism as the basis for PM and SOA predictions, then the priority becomes 

assuring that that mechanism performs sufficiently well in simulating gas-phase processes to reliably 

predict rates of formation of low-volatility PM precursors from gas-phase processes. At a minimum, that 

mechanism should also be suitable for ozone modeling.
120

The work needed to improve the scenarios and methodology for reactivity assessment should be 

given sufficient priority so that it is complete by the time the next reactivity scale update is due. 

Otherwise, we will continue to use the poorly documented EKMA scenarios that are already way out-ofdate, and this may eventually impact the credibility of the reactivity scales as a whole. Ideally this should 

be funded on a national level.
121

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Carter, W. P. L. (1996): "Condensed Atmospheric Photooxidation Mechanisms for Isoprene," Atmos. 

Environ., 30, 4275-4290.

Carter, W. P. L. (2000a): "Documentation of the SAPRC-99 Chemical Mechanism for VOC Reactivity 

Assessment," Report to the California Air Resources Board, Contracts 92-329 and 95-308, May 

8. Available at http://cert.ucr.edu/~carter/absts.htm#saprc99 and http://www.cert.ucr.edu/~carter/ 

reactdat.htm.

Carter, W. P. L. (2000b): "Implementation of the SAPRC-99 Chemical Mechanism into the Models-3 

Framework," Report to the United States Environmental Protection Agency, January 29. 

Available at http://www.cert.ucr.edu/~carter/absts.htm#s99mod3.

Carter, W. P. L. (2003a): "The SAPRC-99 Chemical Mechanism and Updated VOC Reactivity Scales, 

Updated and Corrected Data as of February 5, 2003," Available at http://www.cert.ucr.edu 

/~carter/reactdat.htm.

Carter, W. P. L. (2003b): "Updated Chemical Mechanism for Airshed Model Applications," Research 

Proposal to the California Air Resources Board, October.

Carter, W. P. L. (2004): Evaluation of a Gas-Phase Atmospheric Reaction Mechanism for Low NOx

Conditions," Final Report to California Air Resources Board Contract No. 01-305, May 5. 

Available at http://www.cert.ucr.edu/~carter/absts.htm#lnoxrpt.

Carter, W. P. L. (2007): "Investigation of the Atmospheric Ozone Impacts of Methyl Iodide," Final 

Report to Arysta LifeScience Corporation, Contract UCR-07041867, July 31. Available at 

http://www.cert.ucr.edu/~carter/absts.htm#ch3irep.
125

Carter, W. P. L. (2008a). "Reactivity Estimates for Selected Consumer Product Compounds," Final 

Report to the California Air Resources Board Contract 06-408, February 19. Available at 

http://www.cert.ucr.edu/~carter/absts.htm#aminrep.

Carter, W. P. L. (2008b): "Current Project Information Page: Development of an Improved Chemical 

Speciation Database for Processing Emissions of Volatile Organic Compounds for Air Quality 

Models," Web page available at http://www.cert.ucr.edu/~carter/emitdb/, updated May 27.

Carter, W. P. L. (2008c): "Development of a Condensed SAPRC-07 Chemical Mechanism," Draft Final 

Report to the California Air Resources Board, May 27. Once this report is finalized, it will be 

made available at http://www.cert.ucr.edu/~carter/SAPRC.

Carter, W. P. L. (2009a): "Investigation of the Atmospheric Ozone Impacts of Trans 1,3,3,3-

Tetrafluoropropene," Final Report to Honeywell International Inc. Contract UCR-09010016, 

February 9. Available at http://www.cert.ucr.edu/~carter/absts.htm #ZEErept.

Carter, W. P. L. (2009b): "Investigation of the Atmospheric Ozone Impacts of 2,3,3,3-Tetrafluoropropene," Final Report to Honeywell International Inc. Contract UCR-09010016, June 2. 

Available at http://www.cert.ucr.edu/~carter/absts.htm #YFrept.

Carter, W. P. L. (2009c): "Updated Maximum Incremental Reactivity Scale and Hydrocarbon Bin 

Reactivities For Regulatory Applications," Report to the California Air Resources Board, June 

22. Available at http://www.cert.ucr.edu/~carter/SAPRC.

Carter, W. P. L., R. Atkinson, A. M. Winer, and J. N. Pitts, Jr. (1982): "Experimental Investigation of 

Chamber-Dependent Radical Sources," Int. J. Chem. Kinet., 14, 1071.

Carter, W. P. L., Dodd, M. C., Long, W. D. and Atkinson, R. (1984): Outdoor Chamber Study to Test 

Multi-Day Effects. Volume I: Results and Discussion. Final report, EPA-600/3-84-115.

Carter, W. P. L. and R. Atkinson (1987): "An Experimental Study of Incremental Hydrocarbon 

Reactivity," Environ. Sci. Technol., 21, 670-679

Carter, W. P. L., and F. W. Lurmann (1990): "Evaluation of the RADM Gas-Phase Chemical 

Mechanism," Final Report, EPA-600/3-90-001.

Carter, W. P. L. and F. W. Lurmann (1991): "Evaluation of a Detailed Gas-Phase Atmospheric Reaction 

Mechanism using Environmental Chamber Data," Atm. Environ. 25A, 2771-2806.

Carter, W. P. L., J. A. Pierce, and I. L. Malkina (1992): "Investigation of the Ozone Formation Potential 

of Selected Volatile Silicone Compounds," Final report to Dow-Corning Corporation, November.

Carter, W. P. L., J. A. Pierce, I. L. Malkina, D. Luo and W. D. Long (1993): "Environmental Chamber 

Studies of Maximum Incremental Reactivities of Volatile Organic Compounds," Report to 

Coordinating Research Council, Project No. ME-9, California Air Resources Board Contract No. 

A032-0692; South Coast Air Quality Management District Contract No. C91323, United States 

Environmental Protection Agency Cooperative Agreement No. CR-814396-01-0, University 

Corporation for Atmospheric Research Contract No. 59166, and Dow Corning Corporation. April 

1. Available at http://www.cert.ucr.edu/~carter/absts.htm#rct1rept

Carter, W. P. L., D. Luo, I. L. Malkina, and D. Fitz (1995a): "The University of California, Riverside 

Environmental Chamber Data Base for Evaluating Oxidant Mechanism. Indoor Chamber 

Experiments through 1993," Report submitted to the U. S. Environmental Protection Agency, 

EPA/AREAL, Research Triangle Park, NC, March 20.
126

Carter, W. P. L., D. Luo, I. L. Malkina, and J. A. Pierce (1995b): "Environmental Chamber Studies of 

Atmospheric Reactivities of Volatile Organic Compounds. Effects of Varying Chamber and Light 

Source," Final report to National Renewable Energy Laboratory, Contract XZ-2-12075, 

Coordinating Research Council, Inc., Project M-9, California Air Resources Board, Contract 

A032-0692, and South Coast Air Quality Management District, Contract C91323, March 26.

Carter, W. P. L., D. Luo, I. L. Malkina, and J. A. Pierce (1995c): "Environmental Chamber Studies of 

Atmospheric Reactivities of Volatile Organic Compounds. Effects of Varying ROG Surrogate 

and NOx," Final report to Coordinating Research Council, Inc., Project ME-9, California Air 

Resources Board, Contract A032-0692, and South Coast Air Quality Management District, 

Contract C91323. March 24.

Carter, W. P. L. and R. Atkinson (1996): "Development and Evaluation of a Detailed Mechanism for the 

Atmospheric Reactions of Isoprene and NOx," Int. J. Chem. Kinet., 28, 497-530.

Carter, W. P. L., D. Luo, and I. L. Malkina (1996a): "Investigation of the Atmospheric Ozone Formation 

Potential of Trichloroethylene," Report to the Halogenated Solvents Industry Alliance, August. 

Available at http://www.cert.ucr.edu/~carter/absts.htm#tcerpt.

Carter, W. P. L., D. Luo, and I. L. Malkina (1996b): "Investigation of the Atmospheric Ozone Formation 

Potential of t-Butyl Alcohol, N-Methyl Pyrrolidinone and Propylene Carbonate," Report to 

ARCO Chemical Corporation, July 8.

Carter, W. P. L., D. Luo, and I. L. Malkina (1997a): "Environmental Chamber Studies for Development 

of an Updated Photochemical Mechanism for VOC Reactivity Assessment," final report to 

California Air Resources Board Contract 92-345, Coordinating Research Council Project M-9, 

and National Renewable Energy Laboratory Contract ZF-2-12252-07. November 26. Available at 

Carter, W. P. L., D. Luo and I. L. Malkina (1997b): "Investigation of that Atmospheric Reactions of 

Chloropicrin," Atmos. Environ. 31, 1425-1439; See also Report to the Chloropicrin 

Manufacturers Task Group, May 19. Report available at http://www.cert.ucr.edu/~carter/ 

absts.htm#clpicrin. 

Carter, W. P. L., D. Luo, and I. L. Malkina (1997c): "Investigation of the Atmospheric Ozone Formation 

Potential of Acetylene," Report to Carbide Graphite Corp., April 1. Available at 

http://www.cert.ucr.edu/~carter/absts.htm#acetylr

Carter, W. P. L., D. Luo, I. L. Malkina, S. M. Aschmann and R. Atkinson (1997c): "Investigation of the 

Atmospheric Ozone Formation Potentials of Selected Dibasic Esters," Report to the Dibasic 

Esters Group, SOCMA, August 29.

Carter, W. P. L., D. Luo, and I. L. Malkina (1997d): "Investigation of the Atmospheric Ozone Formation 

Potential of Toluene Diisocyanate," Report to Society of the Plastics Industry, December.

Carter, W. P. L., D. Luo, and I. L. Malkina (1997e): "Investigation of the Atmospheric Ozone Formation 

Potentials of Selected Mineral Spirits Mixtures," Report to Safety-Kleen Corporation, July 25. 

Available at http://www.cert.ucr.edu/~carter/absts.htm#msrept.

Carter, W. P. L., D. Luo, and I. L. Malkina (1999a): "Investigation of the Atmospheric Ozone Formation 

Potential of Para Toluene Isocyanate and Methylene Diphenylene Diisocyanate," Report to the 

Chemical Manufacturers Association Diisocyanates Panel, March. 8. Available at 

http://www.cert.ucr.edu/~carter/absts.htm#mdirpt

Carter, W. P. L., D. Luo, and I. L. Malkina (1999b): ‘Investigation of the Atmospheric Impacts and 

Ozone Formation Potential of Styrene," Report to the Styrene Information and Research Center. 

March 10. Available at http://www.cert.ucr.edu/~carter/absts.htm#styrept.
127

Carter, W. P. L. and E. C. Tuazon (2000): “Atmospheric Chemistry of Bromine Containing Compounds,” 

Report to the Brominated Solvents Consortium, September 27. Available at 

http://www.cert.ucr.edu/~carter/absts.htm#brreport.

Carter, W. P. L., D. Luo, and I. L. Malkina (2000a): "Investigation of the Atmospheric Ozone Formation 

Potentials of Selected Branched Alkanes and Mineral Spirits Samples," Report to Safety-Kleen 

Corporation, July 11. Available at http://www.cert.ucr.edu/~carter/absts.htm#msrpt2.

Carter. W. P. L., D. Luo and I. L. Malkina (2000b): "Investigation of Atmospheric Reactivities of 

Selected Consumer Product VOCs," Report to California Air Resources Board, May 30. 

Available at http://www.cert.ucr.edu/~carter/absts.htm#cpreport.

Carter, W. P. L., D. Luo, and I. L. Malkina (2000c): "Investigation of the Atmospheric Ozone Formation 

Potentials of Selected Carbonates," Report to ExxonMobil Chemical Company, November 17. 

Available at http://www.cert.ucr.edu/~carter/absts.htm#carbonat.

Carter, W. P. L., D. Luo, and I. L. Malkina (2000d): "Investigation of the Atmospheric Ozone Formation 

Potential of Dimethyl Sulfoxide," Report to Gaylord Chemical Corporation, August 21. Available 

at http://www.cert.ucr.edu/~carter/absts.htm#dmsorpt.

Carter, W. P. L., D. Luo, and I. L. Malkina (2000e): "Investigation of the Ozone Formation Potentials of 

Exxsol® D95, Isopar-M®, and the Exxate® Fluids," Report to ExxonMobil Chemical Company, 

October 31. Available at http://www.cert.ucr.edu/~carter/absts.htm#exxprods.

Carter, W. P. L. and I. L. Malkina (2002): "Development and Application of Improved Methods for 

Measurement of Ozone Formation Potentials of Volatile Organic Compounds," Final report to 

California Air Resources Board Contract 97-314, May 22. Available at 

http://www.cert.ucr.edu/~carter/absts.htm#rmethrpt.

Carter, W. P. L. and I. L. Malkina (2005): "Evaluation of Atmospheric Impacts of Selected Coatings 

VOC Emissions," Final report to the California Air Resources Board Contract No. 00-333, March 

21. Available at http://www.cert.ucr.edu/~carter/absts.htm#coatrpt.

Carter, W. P. L., I. L. Malkina, D. R. Cocker III, and C. Song (2005a): "Environmental Chamber Studies 

of VOC Species in Architectural Coatings and Mobile Source Emissions," Final Report to the 

South Coast Air Quality Management District Contract No. 03468, July 5. Available at 

http://www.cert.ucr.edu/~carter/absts.htm#scaqcham.

Carter, W. P. L., D. R. Cocker III, D. R. Fitz, I. L. Malkina, K. Bumiller, C. G. Sauer, J. T. Pisano, C. 

Bufalino, and C. Song (2005b): "A New Environmental Chamber for Evaluation of Gas-Phase 

Chemical Mechanisms and Secondary Aerosol Formation", Atmos. Environ. 39 7768-7788.

Carter, W. P. L. and I. L. Malkina (2007): "Investigation of the Atmospheric Impacts of Selected 

Pesticides," Final Report to the California Air Resources Board Contract 04-334, January 10. 

Available at http://www.cert.ucr.edu/~carter/absts.htm#pestrep.

Chen, Y. and L. Zhu (2001). "The Wavelength Dependence of the Photodissociation of Propionaldehyde 

in the 280-330 nm Region," J.Phys.Chem.A 105, 9689-9696.

Carter, W. P. L., W. S. Goliff, R. Atkinson, J. Arey, and S. M. Aschmann (2010): "Investigation of 

Atmospheric Ozone Impacts of 3-Methoxy-3-Methyl-1-Butanol," Final report to Kuraray, Ltd. 

Will be made available at http://www.cert.ucr.edu/~carter/absts.htm #MMBrept when completed. 

(Estimated completion February, 2010.)

Christensen, L. K., J. Sehested, O. J. Nielsen, M. Bilde, T. J. Wallington, A. Guschin, L. T. Molina, and 

M. J. Molina (1998): "Atmospheric Chemistry of HFE-7200 (C4F9OC2H5): Reaction with OH 

Radicals and Fate of C4F9OCH2CH2O(·) and C4F9OCHO(·)CH3 Radicals,"J. Phys. Chem. A, 

1998, 102, 4839-4845
128

Coquet, S. and P. A. Ariya (2000): "Kinetics of the Gas-Phase Reactions of Cl Atom with Selected C2–

C5 Unsaturated Hydrocarbons at 283 <T< 323 K," Int. J. Chem. Kinet. 32, 478-484.

Cuevas, C. A., A. Notariob, E. Martıneza, and J. Albaladejo (2006): "Temperature-dependence study of 

the gas-phase reactions of atmospheric Cl atoms with a series of aliphatic aldehydes," Atmos. 

Env. 40, 3845–3854.

Dagaut, P., R. Liu, T. J. Wallington, and M. J. Kurylo (1989): "Kinetic Measurements of the Gas-Phase 

Reactions of OH Radicals with Hydroxy Ethers, Hydroxy Ketones, and Keto Ethers," J. Phys. 

Chem, 93, 7838-7840.

Docherty, K. S., W. Wu, Y. B. Lim, and P. J. Ziemann (2005): "Contributions of Organic Peroxides to 

Secondary Aerosol Formed from Reactions of Monoterpenes with O3," Environmental Science 

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Donaghy, T., I. Shanahan, M. Hande and S. Fitzpatrick (1993): Int. J. Chem. Kinet. 25, 273.

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Falbe-Hansen, H., S. Sørensen, N. R. Jensen, T. Pedersen, and J. Hjorth (2000): "Atmospheric Gas-Phase 

Reactions of Dimethylsulfoxide and dimethylsulfone with OH and NO3 radicals, Cl atoms and 

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Fan, J. and R. Zhang (2004): "Atmospheric Oxidation Mechanism of Isoprene," Environ. Chem.. 2004, 1, 

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Fantechi, G, N. R. Jensen, J. Hjorth- and J. Peeters (1998): "Mechanistic Studies of the Atmospheric 

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Gery, M. W., G. Z. Whitten, and J. P. Killus (1988): "Development and Testing of the CBM-IV for Urban 

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Incremental Reactivity (MIR) Values, and Proposed Amendments to Method 310, ‘Determination 

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Reaction of OH Radicals with Selected Dihydroxybenzenes and Benzoquinonesl," Int. J. Chem. 

Kinet. 32, 696-702.

Olariu, R. I., B. Klotz, I. Barnes, K.H. Becker, and R. Mocanu (2002): "FT-IR study of the ring-retaining

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3685-3697.

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135

APPENDIX A. GENERAL MECHANISM LISTING TABLES

This appendix contains the tables giving a complete listing of the base SAPRC-07 mechanism, 

including the version with added chlorine chemistry, and also a listing of the fixed parameter version of 

the lumped mechanism for airshed models. These tables are also available in electronic form in an Excel 

as discussed in Appendix D. Note that Table A-3 is only available in electronic form. This is because of 

its size and the fact that the absorption cross-section and quantum yield are generally more useful in 

electronic form.

Table A-1. List of model species used in the standard base SAPRC-07 mechanism. The lumped 

model species added for the fixed parameter lumped mechanism for airshed models are 

also listed.

Name Description

Constant Species.

O2 Oxygen

M Air

H2O Water

H2 Hydrogen Molecules

HV Light

Active Inorganic Species.

O3 Ozone

NO Nitric Oxide

NO2 Nitrogen Dioxide

NO3 Nitrate Radical

N2O5 Nitrogen Pentoxide

HONO Nitrous Acid

HNO3 Nitric Acid

HNO4 Peroxynitric Acid

HO2H Hydrogen Peroxide

CO Carbon Monoxide

SO2 Sulfur Dioxide

Active Radical Species and Operators.

OH Hydroxyl Radicals

HO2 Hydroperoxide Radicals

MEO2 Methyl Peroxy Radicals

RO2C Peroxy Radical Operator representing NO to NO2 and NO3 to NO2 conversions, and the 

effects of peroxy radical reactions on acyl peroxy and other peroxy radicals.

RO2XC Peroxy Radical Operator representing NO consumption (used in conjunction with organic 

nitrate formation), and the effects of peroxy radical reactions on NO3, acyl peroxy radicals, 

and other peroxy radicals.

MECO3 Acetyl Peroxy Radicals

RCO3 Peroxy Propionyl and higher peroxy acyl Radicals

BZCO3 Peroxyacyl radical formed from Aromatic Aldehydes

MACO3 Peroxyacyl radicals formed from methacrolein and other acroleins.
Table 1 (continued)

136

Name Description

Steady State Radical Species

O3P Ground State Oxygen Atoms

O1D Excited Oxygen Atoms

TBUO t-Butoxy Radicals

BZO Phenoxy Radicals

PAN and PAN Analogues

PAN Peroxy Acetyl Nitrate

PAN2 PPN and other higher alkyl PAN analogues

PBZN PAN analogues formed from Aromatic Aldehydes

MAPAN PAN analogue formed from Methacrolein

Explicit and Lumped Molecule Reactive Organic Product Species

HCHO Formaldehyde

CCHO Acetaldehyde

RCHO Lumped C3+ Aldehydes. Mechanism based on propionaldehyde

ACET Acetone

MEK Ketones and other non-aldehyde oxygenated products that react with OH radicals faster than 

5 x 10-13 but slower than 5 x 10-12 cm3 molec-2sec-1. Mechanism based on methyl ethyl 

ketone.

MEOH Methanol

HCOOH Formic Acid

CCOOH Acetic Acid. Also used for peroxyacetic acid.

RCOOH Higher organic acids and peroxy acids. Mechanism based on propionic acid.

COOH Methyl Hydroperoxide

ROOH Lumped organic hydroperoxides with 2-4 carbons. Mechanism based n-propyl 

hydroperoxide.

R6OOH Lumped organic hydroperoxides with 5 or more carbons (other than those formed following 

OH addition to aromatic rings, which are represented separately). Mechanism based on 3-

hexyl hydroperoxide.

RAOOH Organic hydroperoxides formed following OH addition to aromatic rings, which is 

represented separately because of their probable role in SOA formation. Mechanism based 

on two isomers expected to be formed in the m-xylene system.

GLY Glyoxal

MGLY Methyl Glyoxal

BACL Biacetyl

CRES Phenols and Cresols. Mechanism based on o-cresol.

NPHE Nitrophenols

BALD Aromatic aldehydes. Mechanism based on benzaldehyde

MACR Methacrolein

MVK Methyl Vinyl Ketone

IPRD Lumped isoprene product species. Mechanism based on that of Carter and Atkinson (1996).

Aromatic unsaturated ring fragmentation products (see discussion of aromatic mechanisms)

AFG1 Lumped photoreactive monounsaturated dicarbonyl aromatic fragmentation products that 

photolyze to form radicals.

AFG2 Lumped photoreactive monounsaturated dicarbonyl aromatic fragmentation products that 

photolyze to form non-radical products
Table 1 (continued)

137

Name Description

AFG3 Lumped diunsaturatred dicarbonyl aromatic fragmentation product.

Lumped Parameter Products

PROD2 Ketones and other non-aldehyde oxygenated products that react with OH radicals faster than 

5 x 10-12 cm3 molec-2sec-1. Mechanism based on CH3C(O)CH2CH2CH2OH, CH3C(O)-

CH2CH(CH3)CH2OH, CH3CH2C(O)CH2CH2CH(CH3)OH, CH3CH2C(O)CH2CH2CH(OH)-

CH2CH3, and CH3CH2CH2CH(OH)CH2-CH2C(O)CH2CH3 (PROD2-1 through 5), each 

weighed equally.

RNO3 Lumped Organic Nitrates. Mechanism based on CH3CH2CH(CH3)ONO2, CH3CH(OH)CH2-

CH2CH2ONO2, CH3CH2CH(CH3)CH(CH3)ONO2, CH3CH2CH2CH2CH2CH(ONO2)CH2OH, 

CH3CH2C(CH3)(ONO2)CH2CH(CH3)CH3, and CH3CH2CH2CH2CH2CH2CH2CH(ONO2)-

CH2CH3 (RNO3-1 through 6), each weighed equally.

Steady state operators used to represent radical or product formation in peroxy radical reactions.

xHO2 Formation of HO2 from alkoxy radicals formed in peroxy radical reactions with NO and 

NO3 (100% yields) and RO2 (50% yields)

xOH As above, but for OH

xNO2 As above, but for NO2

xMEO2 As above, but for MEO2

xMECO3 As above, but for MECO3

xRCO3 As above, but for RCO3

xMACO3 As above, but for MACO3

xTBUO As above, but for TBUO

xCO As above, but for CO

xHCHO As above, but for HCHO

xCCHO As above, but for CCHO

xRCHO As above, but for RCHO

xACET As above, but for ACET

xMEK As above, but for MEK

xPROD2 As above, but for PROD2

xGLY As above, but for GLY

xMGLY As above, but for MGLY

xBACL As above, but for BACL

xBALD As above, but for BALD

xAFG1 As above, but for AFG1

xAFG2 As above, but for AFG2

xAFG3 As above, but for AFG3

xMACR As above, but for MACR

xMVK As above, but for MVK

xIPRD As above, but for IPRD

xRNO3 As above, but for RNO3

zRNO3 Formation of RNO3 in the RO2 + NO, reaction, or formation of corresponding non-nitrate 

products (represented by PROD2) formed from alkoxy radicals formed in RO2 + NO3 and 

(in 50% yields) RO2 + RO2 reactions.

yROOH Formation of ROOH following RO2 + HO2 reactions, or formation of H-shift 

disproportionation products (represented by MEK) in the RO2 + RCO3 and (in 50% yields) 

RO2 + RO2 reactions.

yR6OOH As above, but with the RO2 + HO2 product represented by R6OOH and the H-shift products 

are represented by PROD2.
Table 1 (continued)

138

Name Description

yRAOOH As above, but with the RO2 + HO2 product represented by R6OOH

Non-Reacting Species

CO2 Carbon Dioxide

SULF Sulfates (SO3 or H2SO4)

XC Lost Carbon or carbon in unreactive products

XN Lost Nitrogen or nitrogen in unreactive products

Primary Organics Represented explicitly

CH4 Methane

ETHENE Ethene

ISOPRENE Isoprene

ACETYLEN Acetylene

BENZENE Benzene

Lumped model species added to the base mechanism to represent various types of emitted species in the 

lumped mechanism for airshed models (not part of the base mechanism)

ALK1 Alkanes and other non-aromatic compounds that react only with OH, and have kOH (OH 

radical rate constant) between 2 and 5 x 102ppm-1 min-1. (Primarily ethane)

ALK2 Alkanes and other non-aromatic compounds that react only with OH, and have kOH 

between 5 x 102and 2.5 x 103ppm-1 min-1. (Primarily propane)

ALK3 Alkanes and other non-aromatic compounds that react only with OH, and have kOH 

between 2.5 x 103and 5 x 103ppm-1 min-1.

ALK4 Alkanes and other non-aromatic compounds that react only with OH, and have kOH 

between 5 x 103and 1 x 104ppm-1 min-1.

ALK5 Alkanes and other non-aromatic compounds that react only with OH, and have kOH greater 

than 1 x 104ppm-1 min-1.

ARO1 Aromatics with kOH < 2x104ppm-1 min-1.

ARO2 Aromatics with kOH > 2x104ppm-1 min-1.

OLE1 Alkenes (other than ethene) with kOH < 7x104ppm-1 min-1.

OLE2 Alkenes with kOH > 7x104ppm-1 min-1.

TERP Terpenes
139

Table A-2. Listing of reactions and rate parameters in the base SAPRC-07 mechanism.

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

Inorganic Reactions

1 NO2 + HV = NO + O3P Phot Set= NO2-06 2,4

2 O3P + O2 + M = O3 + M 5.68E-34 5.68E-34 0.00 -2.60 3,5

3 O3P + O3 = #2 O2 8.34E-15 8.00E-12 4.09 1,2,3

4 O3P + NO = NO2 1.64E-12 Falloff, F=0.60, N=1.00 2

0: 9.00E-32 0.00 -1.50

inf: 3.00E-11 0.00 0.00

5 O3P + NO2 = NO + O2 1.03E-11 5.50E-12 -0.37 3

6 O3P + NO2 = NO3 3.24E-12 Falloff, F=0.60, N=1.00 2

0: 2.50E-31 0.00 -1.80

inf: 2.20E-11 0.00 -0.70

7 O3 + NO = NO2 + O2 2.02E-14 3.00E-12 2.98 2

8 O3 + NO2 = O2 + NO3 3.72E-17 1.40E-13 4.91 1,3

9 NO + NO3 = #2 NO2 2.60E-11 1.80E-11 -0.22 1,3

10 NO + NO + O2 = #2 NO2 1.93E-38 3.30E-39 -1.05 1,3

11 NO2 + NO3 = N2O5 1.24E-12 Falloff, F=0.35, N=1.33 3

0: 3.60E-30 0.00 -4.10

inf: 1.90E-12 0.00 0.20

12 N2O5 = NO2 + NO3 5.69E-02 Falloff, F=0.35, N=1.33 3

0: 1.30E-03 21.86 -3.50

inf: 9.70E+14 22.02 0.10

13 N2O5 + H2O = #2 HNO3 2.50E-22 3,6

14 N2O5 + H2O + H2O = #2 HNO3 + H2O 1.80E-39 3,6

N2O5 + HV = NO3 + NO + O3P (Slow) 1

N2O5 + HV = NO3 + NO2 (Slow) 1

15 NO2 + NO3 = NO + NO2 + O2 6.75E-16 4.50E-14 2.50 1,3

16 NO3 + HV = NO + O2 Phot Set= NO3NO-06 2

17 NO3 + HV = NO2 + O3P Phot Set= NO3NO2-6 2

18 O3 + HV = O1D + O2 Phot Set= O3O1D-06 2,3,7

19 O3 + HV = O3P + O2 Phot Set= O3O3P-06 2,7

20 O1D + H2O = #2 OH 1.99E-10 1.63E-10 -0.12 2

21 O1D + M = O3P + M 3.28E-11 2.38E-11 -0.19 2,5

22 OH + NO = HONO 7.31E-12 Falloff, F=0.60, N=1.00 2

0: 7.00E-31 0.00 -2.60

inf: 3.60E-11 0.00 -0.10

23 HONO + HV = OH + NO Phot Set= HONO-06 8

24 OH + HONO = H2O + NO2 5.95E-12 2.50E-12 -0.52 3

25 OH + NO2 = HNO3 1.05E-11 Falloff, F=0.60, N=1.00 2,9

0: 1.80E-30 0.00 -3.00

inf: 2.80E-11 0.00 0.00

26 OH + NO3 = HO2 + NO2 2.00E-11 1,3

27 OH + HNO3 = H2O + NO3 1.51E-13 k =k0+k3M/(1+k3M/k2) 2

k0: 2.40E-14 -0.91 0.00
Table A-2 (continued)

140

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

k2: 2.70E-17 -4.37 0.00

k3: 6.50E-34 -2.65 0.00

28 HNO3 + HV = OH + NO2 Phot Set= HNO3 1,2,3,10

29 OH + CO = HO2 + CO2 2.28E-13 k = k1 + k2 [M] 3

k1: 1.44E-13 0.00 0.00

k2: 3.43E-33 0.00 0.00

30 OH + O3 = HO2 + O2 7.41E-14 1.70E-12 1.87 2,3

31 HO2 + NO = OH + NO2 8.85E-12 3.60E-12 -0.54 3

32 HO2 + NO2 = HNO4 1.12E-12 Falloff, F=0.60, N=1.00 2

0: 2.00E-31 0.00 -3.40

inf: 2.90E-12 0.00 -1.10

33 HNO4 = HO2 + NO2 1.07E-01 Falloff, F=0.60, N=1.00 11

0: 3.72E-05 21.16 -2.40

inf: 5.42E+15 22.20 -2.30

34 HNO4 + HV = #.61 {HO2 + NO2} + #.39 

{OH + NO3}

Phot Set= HNO4-06 12

35 HNO4 + OH = H2O + NO2 + O2 4.61E-12 1.30E-12 -0.76 2

36 HO2 + O3 = OH + #2 O2 2.05E-15 2.03E-16 -1.38 4.57 3

37 HO2 + HO2 = HO2H + O2 2.84E-12 k = k1 + k2 [M] 3

k1: 2.20E-13 -1.19 0.00

k2: 1.90E-33 -1.95 0.00

38 HO2 + HO2 + H2O = HO2H + O2 + H2O 6.09E-30 k = k1 + k2 [M] 3

k1: 3.08E-34 -5.56 0.00

k2: 2.66E-54 -6.32 0.00

39 NO3 + HO2 = #.8 {OH + NO2 + O2} + #.2 

{HNO3 + O2}

4.00E-12 1,3,13

40 NO3 + NO3 = #2 NO2 + O2 2.41E-16 8.50E-13 4.87 1,2

41 HO2H + HV = #2 OH Phot Set= H2O2 1,10

42 HO2H + OH = HO2 + H2O 1.80E-12 1.80E-12 0.00 2

43 OH + HO2 = H2O + O2 1.10E-10 4.80E-11 -0.50 1

44 OH + SO2 = HO2 + SULF 9.49E-13 Falloff, F=0.60, N=1.00 2

0: 3.30E-31 0.00 -4.30

inf: 1.60E-12 0.00 0.00

45 OH + H2 = HO2 + H2O 7.02E-15 7.70E-12 4.17 1,3

Methyl peroxy and methoxy reactions

BR01 MEO2 + NO = NO2 + HCHO + HO2 7.64E-12 2.30E-12 -0.72 3,14

BR02 MEO2 + HO2 = COOH + O2 4.65E-12 3.46E-13 -1.55 0.36 3,15

BR03 MEO2 + HO2 = HCHO + O2 + H2O 4.50E-13 3.34E-14 -1.55 -3.53 3,15

BR04 MEO2 + NO3 = HCHO + HO2 + NO2 1.30E-12 1,3,14

BR05 MEO2 + MEO2 = MEOH + HCHO + O2 2.16E-13 6.39E-14 -0.73 -1.80 3,16

BR06 MEO2 + MEO2 = #2 {HCHO + HO2} 1.31E-13 7.40E-13 1.03 3

Active Peroxy Radical Operators

BR07 RO2C + NO = NO2 9.23E-12 2.60E-12 -0.76 3,18,17

BR08 RO2C + HO2 = 7.63E-12 3.80E-13 -1.79 3,18,17
Table A-2 (continued)

141

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

BR09 RO2C + NO3 = NO2 2.30E-12 3,18,17

BR10 RO2C + MEO2 = #.5 HO2 + #.75 HCHO + 

#.25 MEOH

2.00E-13 1,17,19

BR11 RO2C + RO2C = 3.50E-14 1,17

BR12 RO2XC + NO = XN Same k as rxn BR07 3,17,18

BR13 RO2XC + HO2 = Same k as rxn BR08 3,17,18

BR14 RO2XC + NO3 = NO2 Same k as rxn BR09 1,17

BR15 RO2XC + MEO2 = #.5 HO2 + #.75 HCHO + 

#.25 MEOH

Same k as rxn BR10 3,17,18

BR16 RO2XC + RO2C = Same k as rxn BR11 1,17

BR17 RO2XC + RO2XC = Same k as rxn BR11 1,17

Reactions of Acyl Peroxy Radicals, PAN, and PAN analogues

BR18 MECO3 + NO2 = PAN 9.37E-12 Falloff, F=0.30, N=1.41 20

0: 2.70E-28 0.00 -7.10

inf: 1.21E-11 0.00 -0.90

BR19 PAN = MECO3 + NO2 6.27E-04 Falloff, F=0.30, N=1.41 20

0: 4.90E-03 24.05 0.00

inf: 4.00E+16 27.03 0.00

BR20 PAN + HV = #.6 {MECO3 + NO2} + #.4 

{MEO2 + CO2 + NO3}

Phot Set= PAN 3

BR21 MECO3 + NO = MEO2 + CO2 + NO2 1.97E-11 7.50E-12 -0.58 3

BR22 MECO3 + HO2 = CCOOH + #.7 O2 + #.3 O3 1.36E-11 5.20E-13 -1.95 3,21

BR23 MECO3 + NO3 = MEO2 + CO2 + NO2 + O2 Same k as rxn BR09 22

BR24 MECO3 + MEO2 = #.1 {CCOOH + HCHO + 

O2} + #.9 {HCHO + HO2 + MEO2 + CO2}

1.06E-11 2.00E-12 -0.99 3

BR25 MECO3 + RO2C = MEO2 + CO2 1.56E-11 4.40E-13 -2.13 3,18,23

BR26 MECO3 + RO2XC = MEO2 + CO2 Same k as rxn BR25 3,18,23

BR27 MECO3 + MECO3 = #2 {MEO2 + CO2} + 

O2

1.54E-11 2.90E-12 -0.99 1,3

BR28 RCO3 + NO2 = PAN2 1.21E-11 1.21E-11 0.00 -1.07 24

BR29 PAN2 = RCO3 + NO2 5.48E-04 8.30E+16 27.70 3,25

BR30 PAN2 + HV = #.6 {RCO3 + NO2} + #.4 

{RO2C + xHO2 + yROOH + xCCHO + CO2 

+ NO3}

Phot Set= PAN 26

BR31 RCO3 + NO = NO2 + RO2C + xHO2 + 

yROOH + xCCHO + CO2

2.08E-11 6.70E-12 -0.68 3,27

BR32 RCO3 + HO2 = RCOOH + #.75 O2 + #.25 O3 Same k as rxn BR22 1,28

BR33 RCO3 + NO3 = NO2 + RO2C + xHO2 + 

yROOH + xCCHO + CO2 + O2

Same k as rxn BR09 1,28

BR34 RCO3 + MEO2 = HCHO + HO2 + RO2C + 

xHO2 + xCCHO + yROOH + CO2

Same k as rxn BR24 1,28

BR35 RCO3 + RO2C = RO2C + xHO2 + xCCHO + 

yROOH + CO2

Same k as rxn BR25 1,28
Table A-2 (continued)

142

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

BR36 RCO3 + RO2XC = RO2C + xHO2 + xCCHO 

+ yROOH + CO2

Same k as rxn BR25 1,28

BR37 RCO3 + MECO3 = #2 CO2 + MEO2 + RO2C 

+ xHO2 + yROOH + xCCHO + O2

Same k as rxn BR27 1,28

BR38 RCO3 + RCO3 = #2 {RO2C + xHO2 + 

xCCHO + yROOH + CO2}

Same k as rxn BR27 1,28

BR39 BZCO3 + NO2 = PBZN 1.37E-11 1,29

BR40 PBZN = BZCO3 + NO2 4.27E-04 7.90E+16 27.82 1,29

BR41 PBZN + HV = #.6 {BZCO3 + NO2} + #.4 

{CO2 + BZO + RO2C + NO3}

Phot Set= PAN 26

BR42 BZCO3 + NO = NO2 + CO2 + BZO + RO2C Same k as rxn BR31 1,28

BR43 BZCO3 + HO2 = RCOOH + #.75 O2 + #.25 

O3 + #4 XC

Same k as rxn BR22 1,28

BR44 BZCO3 + NO3 = NO2 + CO2 + BZO + RO2C 

+ O2

Same k as rxn BR09 1,28

BR45 BZCO3 + MEO2 = HCHO + HO2 + RO2C + 

BZO + CO2

Same k as rxn BR24 1,28

BR46 BZCO3 + RO2C = RO2C + BZO + CO2 Same k as rxn BR25 1,28

BR47 BZCO3 + RO2XC = RO2C + BZO + CO2 Same k as rxn BR25 1,28

BR48 BZCO3 + MECO3 = #2 CO2 + MEO2 + BZO 

+ RO2C

Same k as rxn BR27 1,28

BR49 BZCO3 + RCO3 = #2 CO2 + RO2C + xHO2 + 

yROOH + xCCHO + BZO + RO2C

Same k as rxn BR27 1,28

BR50 BZCO3 + BZCO3 = #2 {BZO + RO2C + 

CO2}

Same k as rxn BR27 1,28

BR51 MACO3 + NO2 = MAPAN Same k as rxn BR28 1,28

BR52 MAPAN = MACO3 + NO2 4.79E-04 1.60E+16 26.80 1,30

BR53 MAPAN + HV = #.6 {MACO3 + NO2} + #.4 

{CO2 + HCHO + MECO3 + NO3}

Phot Set= PAN 26

BR54 MACO3 + NO = NO2 + CO2 + HCHO + 

MECO3

Same k as rxn BR31 1,28

BR55 MACO3 + HO2 = RCOOH + #.75 O2 + #.25 

O3 + XC

Same k as rxn BR22 1,28

BR56 MACO3 + NO3 = NO2 + CO2 + HCHO + 

MECO3 + O2

Same k as rxn BR09 1,28

BR57 MACO3 + MEO2 = #2 HCHO + HO2 + CO2 

+ MECO3

Same k as rxn BR24 1,28

BR58 MACO3 + RO2C = CO2 + HCHO + MECO3 Same k as rxn BR25 1,28

BR59 MACO3 + RO2XC = CO2 + HCHO + 

MECO3

Same k as rxn BR25 1,28

BR60 MACO3 + MECO3 = #2 CO2 + MEO2 + 

HCHO + MECO3 + O2

Same k as rxn BR27 1,28

BR61 MACO3 + RCO3 = HCHO + MECO3 + 

RO2C + xHO2 + yROOH + xCCHO + #2 

CO2

Same k as rxn BR27 1,28
Table A-2 (continued)

143

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

BR62 MACO3 + BZCO3 = HCHO + MECO3 + 

BZO + RO2C + #2 CO2

Same k as rxn BR27 1,28

BR63 MACO3 + MACO3 = #2 {HCHO + MECO3 

+ CO2}

Same k as rxn BR27 1,28

Other Organic Radical Species

BR64 TBUO + NO2 = RNO3 + #-2 XC 2.40E-11 1

BR65 TBUO = ACET + MEO2 1.18E+03 7.50E+14 16.20 1

BR66 BZO + NO2 = NPHE 3.79E-11 2.30E-11 -0.30 1

BR67 BZO + HO2 = CRES + #-1 XC Same k as rxn BR08 1

BR68 BZO = CRES + RO2C + xHO2 + #-1 XC 1.00E-03 1,31

Steady-State Peroxy Radical operators (for formation of inorganic and radical products)

RO01 xHO2 = HO2 k is variable parameter: RO2RO 32

RO02 xHO2 = k is variable parameter: RO2XRO 32

RO03 xOH = OH k is variable parameter: RO2RO 32

RO04 xOH = k is variable parameter: RO2XRO 32

RO05 xNO2 = NO2 k is variable parameter: RO2RO 32

RO06 xNO2 = XN k is variable parameter: RO2XRO 32

RO07 xMEO2 = MEO2 k is variable parameter: RO2RO 32

RO08 xMEO2 = XC k is variable parameter: RO2XRO 32

RO09 xMECO3 = MECO3 k is variable parameter: RO2RO 32

RO10 xMECO3 = #2 XC k is variable parameter: RO2XRO 32

RO11 xRCO3 = RCO3 k is variable parameter: RO2RO 32

RO12 xRCO3 = #3 XC k is variable parameter: RO2XRO 32

RO13 xMACO3 = MACO3 k is variable parameter: RO2RO 32

RO14 xMACO3 = #4 XC k is variable parameter: RO2XRO 32

RO15 xTBUO = TBUO k is variable parameter: RO2RO 32

RO16 xTBUO = #4 XC k is variable parameter: RO2XRO 32

RO17 xCO = CO k is variable parameter: RO2RO 32

RO18 xCO = XC k is variable parameter: RO2XRO 32

Explicit and Lumped Molecule Organic Products

BP01 HCHO + HV = #2 HO2 + CO Phot Set= HCHOR-06 3

BP02 HCHO + HV = H2 + CO Phot Set= HCHOM-06 3

BP03 HCHO + OH = HO2 + CO + H2O 8.47E-12 5.40E-12 -0.27 3

BP04 HCHO + HO2 = HOCOO Assumed to be negligible 34

BP07 HCHO + NO3 = HNO3 + HO2 + CO 6.06E-16 2.00E-12 4.83 1,33

BP08 CCHO + OH = MECO3 + H2O 1.49E-11 4.40E-12 -0.73 3

BP09 CCHO + HV = CO + HO2 + MEO2 Phot Set= CCHO_R 1,3

BP10 CCHO + NO3 = HNO3 + MECO3 2.84E-15 1.40E-12 3.70 1,3

BP11 RCHO + OH = #.965 RCO3 + #.035 {RO2C + 

xHO2 + xCO + xCCHO + yROOH}

1.97E-11 5.10E-12 -0.80 36,35

BP12 RCHO + HV = RO2C + xHO2 + yROOH + 

xCCHO + CO + HO2

Phot Set= C2CHO 1,37

BP13 RCHO + NO3 = HNO3 + RCO3 6.74E-15 1.40E-12 3.18 38
Table A-2 (continued)

144

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

BP14 ACET + OH = RO2C + xMECO3 + xHCHO + 

yROOH

1.91E-13 4.56E-14 -0.85 3.65 39

BP15 ACET + HV = #.62 MECO3 + #1.38 MEO2 + 

#.38 CO

Phot Set= ACET-06, qy= 0.5 40

BP16 MEK + OH = #.967 RO2C + #.039 {RO2XC 

+ zRNO3} + #.376 xHO2 + #.51 xMECO3 + 

#.074 xRCO3 + #.088 xHCHO + #.504 

xCCHO + #.376 xRCHO + yROOH + #.3 XC

1.20E-12 1.30E-12 0.05 2.00 1,3,36

BP17 MEK + HV = MECO3 + RO2C + xHO2 + 

xCCHO + yROOH

Phot Set= MEK-06, qy= 0.175 41

BP18 MEOH + OH = HCHO + HO2 9.02E-13 2.85E-12 0.69 3

BP19 HCOOH + OH = HO2 + CO2 4.50E-13 3,42

BP20 CCOOH + OH = #.509 MEO2 + #.491 RO2C 

+ #.509 CO2 + #.491 xHO2 + #.491 xMGLY 

+ #.491 yROOH + #-0.491 XC

7.26E-13 4.20E-14 -1.70 3,36

BP21 RCOOH + OH = RO2C + xHO2 + #.143 CO2 

+ #.142 xCCHO + #.4 xRCHO + #.457 

xBACL + yROOH + #-0.455 XC

1.20E-12 3,36

BP22 COOH + OH = H2O + #.3 {HCHO + OH} + 

#.7 MEO2

7.40E-12 3.80E-12 -0.40 2,43

BP23 COOH + HV = HCHO + HO2 + OH Phot Set= COOH 1,3

BP24 ROOH + OH = #.744 OH + #.251 RO2C + 

#.004 RO2XC + #.004 zRNO3 + #.744 RCHO 

+ #.239 xHO2 + #.012 xOH + #.012 xHCHO 

+ #.012 xCCHO + #.205 xRCHO + #.034 

xPROD2 + #.256 yROOH + #-0.115 XC

2.50E-11 36,45,44

BP25 ROOH + HV = RCHO + HO2 + OH Phot Set= COOH 1,45

BP26 R6OOH + OH = #.84 OH + #.222 RO2C + 

#.029 RO2XC + #.029 zRNO3 + #.84 PROD2 

+ #.09 xHO2 + #.041 xOH + #.02 xCCHO + 

#.075 xRCHO + #.084 xPROD2 + #.16 

yROOH + #.02 XC

5.60E-11 36,44,46

BP27 R6OOH + HV = OH + #.142 HO2 + #.782 

RO2C + #.077 RO2XC + #.077 zRNO3 + 

#.085 RCHO + #.142 PROD2 + #.782 xHO2 + 

#.026 xCCHO + #.058 xRCHO + #.698 

xPROD2 + #.858 yR6OOH + #.017 XC

Phot Set= COOH 46

BP28 RAOOH + OH = #.139 OH + #.148 HO2 + 

#.589 RO2C + #.124 RO2XC + #.124 zRNO3 

+ #.074 PROD2 + #.147 MGLY + #.139 IPRD 

+ #.565 xHO2 + #.024 xOH + #.448 xRCHO + 

#.026 xGLY + #.030 xMEK + #.252 xMGLY 

+ #.073 xAFG1 + #.073 xAFG2 + #.713 

yR6OOH + #2.674 XC

1.41E-10 47
Table A-2 (continued)

145

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

BP29 RAOOH + HV = OH + HO2 + #.5 {GLY + 

MGLY + AFG1 + AFG2} + #.5 XC

Phot Set= COOH 47

BP30 GLY + HV = #2 {CO + HO2} Phot Set= GLY-07R 48

BP31 GLY + HV = HCHO + CO Phot Set= GLY-07M 48

BP32 GLY + OH = #.63 HO2 + #1.26 CO + #.37 

RCO3 + #-.37 XC

1.10E-11 1,3,49

BP33 GLY + NO3 = HNO3 + #.63 HO2 + #1.26 CO 

+ #.37 RCO3 + #-.37 XC

1.02E-15 2.80E-12 4.72 1,50

BP34 MGLY + HV = HO2 + CO + MECO3 Phot Set= MGLY-06 3,51

BP35 MGLY + OH = CO + MECO3 1.50E-11 1,3

BP36 MGLY + NO3 = HNO3 + CO + MECO3 2.53E-15 1.40E-12 3.77 1,50

BP37 BACL + HV = #2 MECO3 Phot Set= BACL-07 52

BP38 CRES + OH = #.2 BZO + #.8 {RO2C + xHO2 

+ yR6OOH} + #.25 xMGLY + #5.05 XC

4.03E-11 1.70E-12 -1.89 53,54

BP39 CRES + NO3 = HNO3 + BZO + XC 1.40E-11 1,53

BP40 NPHE + OH = BZO + XN 3.50E-12 55

BP41 NPHE + HV = HONO + #6 XC Phot Set= NO2-06, qy= 1.5e-3 56

BP42 NPHE + HV = #6 XC + XN Phot Set= NO2-06, qy= 1.5e-2 57

BP43 BALD + OH = BZCO3 1.20E-11 59,58

BP44 BALD + HV = #7 XC Phot Set= BALD-06, qy= 0.06 60

BP45 BALD + NO3 = HNO3 + BZCO3 2.73E-15 1.34E-12 3.70 1,61

Lumped Unsaturated Aromatic Ring-Opening Products

BP46 AFG1 + OH = #.217 MACO3 + #.723 RO2C 

+ #.060 {RO2XC + zRNO3} + #.521 xHO2 + 

#.201 xMECO3 + #.334 xCO + #.407 xRCHO 

+ #.129 xMEK + #.107 xGLY + #.267 

xMGLY + #.783 yR6OOH + #.284 XC

7.40E-11 62

BP47 AFG1 + O3 = #.826 OH + #.522 HO2 + #.652 

RO2C + #.522 CO + #.174 CO2 + #.432 GLY 

+ #.568 MGLY + #.652 xRCO3 + #.652 

xHCHO + #.652 yR6OOH + #-.872 XC

9.66E-18 62

BP48 AFG1 + HV = #1.023 HO2 + #.173 MEO2 + 

#.305 MECO3 + #.500 MACO3 + #.695 CO + 

#.195 GLY + #.305 MGLY + #.217 XC

Phot Set= AFG1 62,63

BP49 AFG2 + OH = #.217 MACO3 + #.723 RO2C 

+ #.060 {RO2XC + zRNO3} + #.521 xHO2 + 

#.201 xMECO3 + #.334 xCO + #.407 xRCHO 

+ #.129 xMEK + #.107 xGLY + #.267 

xMGLY + #.783 yR6OOH + #.284 XC

7.40E-11 62

BP50 AFG2 + O3 = #.826 OH + #.522 HO2 + #.652 

RO2C + #.522 CO + #.174 CO2 + #.432 GLY 

+ #.568 MGLY + #.652 xRCO3 + #.652 

xHCHO + #.652 yR6OOH + #-.872 XC

9.66E-18 62
Table A-2 (continued)

146

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

BP51 AFG2 + HV = PROD2 + #-1 XC Phot Set= AFG1 62,63

BP52 AFG3 + OH = #.206 MACO3 + #.733 RO2C 

+ #.117 {RO2XC + zRNO3} + #.561 xHO2 + 

#.117 xMECO3 + #.114 xCO + #.274 xGLY + 

#.153 xMGLY + #.019 xBACL + #.195 

xAFG1 + #.195 xAFG2 + #.231 xIPRD + 

#.794 yR6OOH + #.938 XC

9.35E-11 64

BP53 AFG3 + O3 = #.471 OH + #.554 HO2 + #.013 

MECO3 + #.258 RO2C + #.007 {RO2XC + 

zRNO3} + #.580 CO + #.190 CO2 + #.366 

GLY + #.184 MGLY + #.350 AFG1 + #.350 

AFG2 + #.139 AFG3 + #.003 MACR + #.004 

MVK + #.003 IPRD + #.095 xHO2 + #.163 

xRCO3 + #.163 xHCHO + #.095 xMGLY + 

#.264 yR6OOH + #-.575 XC

1.43E-17 64

Isoprene Products

BP54 MACR + OH = #.5 MACO3 + #.5 {RO2C + 

xHO2} + #.416 xCO + #.084 xHCHO + #.416 

xMEK + #.084 xMGLY + #.5 yROOH + #-

0.416 XC

2.84E-11 8.00E-12 -0.76 3,65

BP55 MACR + O3 = #.208 OH + #.108 HO2 + #.1 

RO2C + #.45 CO + #.117 CO2 + #.1 HCHO + 

#.9 MGLY + #.333 HCOOH + #.1 xRCO3 + 

#.1 xHCHO + #.1 yROOH + #-0.1 XC

1.28E-18 1.40E-15 4.17 3,65

BP56 MACR + NO3 = #.5 {MACO3 + RO2C + 

HNO3 + xHO2 + xCO} + #.5 yROOH + #1.5 

XC + #.5 XN

3.54E-15 1.50E-12 3.61 65,66

BP57 MACR + O3P = RCHO + XC 6.34E-12 1,65

BP58 MACR + HV = #.33 OH + #.67 HO2 + #.34 

MECO3 + #.33 MACO3 + #.33 RO2C + #.67 

CO + #.34 HCHO + #.33 xMECO3 + #.33 

xHCHO + #.33 yROOH

Phot Set= MACR-06 3,65,67

BP59 MVK + OH = #.975 RO2C + #.025 {RO2XC 

+ zRNO3} + #.3 xHO2 + #.675 xMECO3 + 

#.3 xHCHO + #.675 xRCHO + #.3 xMGLY + 

yROOH + #-0.725 XC

1.99E-11 2.60E-12 -1.21 3,65

BP60 MVK + O3 = #.164 OH + #.064 HO2 + #.05 

{RO2C + xHO2} + #.475 CO + #.124 CO2 + 

#.05 HCHO + #.95 MGLY + #.351 HCOOH + 

#.05 xRCO3 + #.05 xHCHO + #.05 yROOH + 

#-0.05 XC

5.36E-18 8.50E-16 3.02 3,65

BP61 MVK + NO3 = #4 XC + XN (Slow) 1,65

BP62 MVK + O3P = #.45 RCHO + #.55 MEK + 

#.45 XC

4.32E-12 1,65
Table A-2 (continued)

147

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

BP63 MVK + HV = #.4 MEO2 + #.6 CO + #.6 

PROD2 + #.4 MACO3 + #-2.2 XC

Phot Set= MVK-06 3,68

BP64 IPRD + OH = #.289 MACO3 + #.67 {RO2C + 

xHO2} + #.041 {RO2XC + zRNO3} + #.336 

xCO + #.055 xHCHO + #.129 xCCHO + #.013 

xRCHO + #.15 xMEK + #.332 xPROD2 + 

#.15 xGLY + #.174 xMGLY + #-0.504 XC + 

#.711 yR6OOH

6.19E-11 1,65

BP65 IPRD + O3 = #.285 OH + #.4 HO2 + #.048 

{RO2C + xRCO3} + #.498 CO + #.14 CO2 + 

#.124 HCHO + #.21 MEK + #.023 GLY + 

#.742 MGLY + #.1 HCOOH + #.372 RCOOH 

+ #.047 xCCHO + #.001 xHCHO + #.048 

yR6OOH + #-.329 XC

4.18E-18 1,65

BP66 IPRD + NO3 = #.15 {MACO3 + HNO3} + 

#.799 {RO2C + xHO2} + #.051 {RO2XC + 

zRNO3} + #.572 xCO + #.227 xHCHO + 

#.218 xRCHO + #.008 xMGLY + #.572 

xRNO3 + #.85 yR6OOH + #.278 XN + #-.815 

XC

1.00E-13 1,65

BP67 IPRD + HV = #1.233 HO2 + #.467 MECO3 + 

#.3 RCO3 + #1.233 CO + #.3 HCHO + #.467 

CCHO + #.233 MEK + #-.233 XC

Phot Set= MACR-06 65,69

Lumped Parameter Organic Products

BP68 PROD2 + OH = #.472 HO2 + #.379 xHO2 + 

#.029 xMECO3 + #.049 xRCO3 + #.473 

RO2C + #.071 RO2XC + #.071 zRNO3 + 

#.002 HCHO + #.211 xHCHO + #.001 CCHO 

+ #.083 xCCHO + #.143 RCHO + #.402 

xRCHO + #.115 xMEK + #.329 PROD2 + 

#.007 xPROD2 + #.528 yR6OOH + #.877 XC

1.55E-11 70

BP69 PROD2 + HV = #.913 xHO2 + #.4 MECO3 + 

#.6 RCO3 + #1.59 RO2C + #.087 RO2XC + 

#.087 zRNO3 + #.303 xHCHO + #.163 

xCCHO + #.78 xRCHO + yR6OOH + #-.091 

XC

Phot Set= MEK-06, qy= 4.86e-3 70,71

BP70 RNO3 + OH = #.189 HO2 + #.305 xHO2 + 

#.019 NO2 + #.313 xNO2 + #.976 RO2C + 

#.175 RO2XC + #.175 zRNO3 + #.011 

xHCHO + #.429 xCCHO + #.001 RCHO + 

#.036 xRCHO + #.004 xACET + #.01 MEK + 

#.17 xMEK + #.008 PROD2 + #.031 xPROD2 

+ #.189 RNO3 + #.305 xRNO3 + #.157 

yROOH + #.636 yR6OOH + #.174 XN + #.04 

XC

7.20E-12 72
Table A-2 (continued)

148

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

BP71 RNO3 + HV = #.344 HO2 + #.554 xHO2 + 

NO2 + #.721 RO2C + #.102 RO2XC + #.102 

zRNO3 + #.074 HCHO + #.061 xHCHO + 

#.214 CCHO + #.23 xCCHO + #.074 RCHO + 

#.063 xRCHO + #.008 xACET + #.124 MEK 

+ #.083 xMEK + #.19 PROD2 + #.261 

xPROD2 + #.066 yROOH + #.591 yR6OOH +

#.396 XC

Phot Set= IC3ONO2 72,73

Steady-State Peroxy Radical operators (for formation of organic product species)

PO01 xHCHO = HCHO k is variable parameter: RO2RO 32

PO02 xHCHO = XC k is variable parameter: RO2XRO 32

PO03 xCCHO = CCHO k is variable parameter: RO2RO 32

PO04 xCCHO = #2 XC k is variable parameter: RO2XRO 32

PO05 xRCHO = RCHO k is variable parameter: RO2RO 32

PO06 xRCHO = #3 XC k is variable parameter: RO2XRO 32

PO07 xACET = ACET k is variable parameter: RO2RO 32

PO08 xACET = #3 XC k is variable parameter: RO2XRO 32

PO09 xMEK = MEK k is variable parameter: RO2RO 32

PO10 xMEK = #4 XC k is variable parameter: RO2XRO 32

PO11 xPROD2 = PROD2 k is variable parameter: RO2RO 32

PO12 xPROD2 = #6 XC k is variable parameter: RO2XRO 32

PO13 xGLY = GLY k is variable parameter: RO2RO 32

PO14 xGLY = #2 XC k is variable parameter: RO2XRO 32

PO15 xMGLY = MGLY k is variable parameter: RO2RO 32

PO16 xMGLY = #3 XC k is variable parameter: RO2XRO 32

PO17 xBACL = BACL k is variable parameter: RO2RO 32

PO18 xBACL = #4 XC k is variable parameter: RO2XRO 32

PO19 xBALD = BALD k is variable parameter: RO2RO 32

PO20 xBALD = #7 XC k is variable parameter: RO2XRO 32

PO21 xAFG1 = AFG1 k is variable parameter: RO2RO 32

PO22 xAFG1 = #5 XC k is variable parameter: RO2XRO 32

PO23 xAFG2 = AFG2 k is variable parameter: RO2RO 32

PO24 xAFG2 = #5 XC k is variable parameter: RO2XRO 32

PO25 xAFG3 = AFG3 k is variable parameter: RO2RO 32

PO26 xAFG3 = #7 XC k is variable parameter: RO2XRO 32

PO27 xMACR = MACR k is variable parameter: RO2RO 32

PO28 xMACR = #4 XC k is variable parameter: RO2XRO 32

PO29 xMVK = MVK k is variable parameter: RO2RO 32

PO30 xMVK = #4 XC k is variable parameter: RO2XRO 32

PO31 xIPRD = IPRD k is variable parameter: RO2RO 32

PO32 xIPRD = #5 XC k is variable parameter: RO2XRO 32

PO33 xRNO3 = RNO3 k is variable parameter: RO2RO 32

PO34 xRNO3 = #6 XC + XN k is variable parameter: RO2XRO 32

PO35 zRNO3 = RNO3 + #-1 XN k is variable parameter: RO2NO 74

PO36 zRNO3 = PROD2 + HO2 k is variable parameter: RO22NN 74
Table A-2 (continued)

149

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

PO37 zRNO3 = #6 XC k is variable parameter: RO2XRO 74

PO38 yROOH = ROOH + #-3 XC k is variable parameter: RO2HO2 75

PO39 yROOH = MEK + #-4 XC k is variable parameter: RO2RO2M 75

PO40 yROOH = k is variable parameter: RO2RO 75

PO41 yR6OOH = R6OOH + #-6 XC k is variable parameter: RO2HO2 75

PO42 yR6OOH = PROD2 + #-6 XC k is variable parameter: RO2RO2M 75

PO43 yR6OOH = k is variable parameter: RO2RO 75

PO44 yRAOOH = RAOOH + #-8 XC k is variable parameter: RO2HO2 75

PO45 yRAOOH = PROD2 + #-6 XC k is variable parameter: RO2RO2M 75

PO46 yRAOOH = k is variable parameter: RO2RO 75

Explicitly Represented Primary Organics

BE01 CH4 + OH = H2O + MEO2 6.62E-15 1.85E-12 3.36 1,59

BE02 ETHENE + OH = RO2C + xHO2 + #1.61 

xHCHO + #.195 xCCHO + yROOH

8.15E-12 Falloff, F=0.60, N=1.00 2,76

0: 1.00E-28 0.00 -4.50

inf: 8.80E-12 0.00 -0.85

BE03 ETHENE + O3 = #.16 OH + #.16 HO2 + #.51 

CO + #.12 CO2 + HCHO + #.37 HCOOH

1.68E-18 9.14E-15 5.13 59,77

BE04 ETHENE + NO3 = RO2C + xHO2 + xRCHO 

+ yROOH + #-1 XC + XN

2.24E-16 3.30E-12 5.72 2.00 3,76

BE05 ETHENE + O3P = #.8 HO2 + #.51 MEO2 + 

#.29 RO2C + #.51 CO + #.1 CCHO + #.29 

xHO2 + #.278 xCO + #.278 xHCHO + #.012 

xGLY + #.29 yROOH + #.2 XC

7.43E-13 1.07E-11 1.59 59,78

BE06 ISOPRENE + OH = #.986 RO2C + #.093 

{RO2XC + zRNO3} + #.907 xHO2 + #.624 

xHCHO + #.23 xMACR + #.32 xMVK + 

#.357 xIPRD + yR6OOH + #-0.167 XC

9.96E-11 2.54E-11 -0.81 1,65,79

BE07 ISOPRENE + O3 = #.266 OH + #.066 HO2 + 

#.192 RO2C + #.008 {RO2XC + zRNO3} + 

#.275 CO + #.122 CO2 + #.4 HCHO + #.1 

PROD2 + #.39 MACR + #.16 MVK + #.15 

IPRD + #.204 HCOOH + #.192 {xMACO3 + 

xHCHO} + #.2 yR6OOH + #-0.559 XC

1.34E-17 7.86E-15 3.80 1,65

BE08 ISOPRENE + NO3 = #.936 RO2C + #.064 

{RO2XC + zRNO3} + #.749 xHO2 + #.187 

xNO2 + #.936 xIPRD + yR6OOH + #-0.064 

XC + #.813 XN

6.81E-13 3.03E-12 0.89 1,65

BE09 ISOPRENE + O3P = #.25 MEO2 + #.24 

RO2C + #.01 {RO2XC + zRNO3} + #.75 

PROD2 + #.24 xMACO3 + #.24 xHCHO + 

#.25 yR6OOH + #-1.01 XC

3.50E-11 65,79

BE10 ACETYLEN + OH = #.7 OH + #.3 HO2 + #.3 

CO + #.7 GLY + #.3 HCOOH

7.56E-13 Falloff, F=0.60, N=1.00 2,80,81
Table A-2 (continued)

150

Label Reaction and Products [a] Rate Parameters [b] Refs &

k(300) A Ea B Notes [c]

BE11 ACETYLEN + O3 = #.5 OH + #1.5 HO2 + 

#1.5 CO + #.5 CO2

1.16E-20 1.00E-14 8.15 2,81,82

BE12 BENZENE + OH = #.116 OH + #.29 {RO2C 

+ xHO2} + #.024 {RO2XC + zRNO3} + #.57 

{HO2 + CRES} + #.116 AFG3 + #.290 xGLY 

+ #.029 xAFG1 + #.261 xAFG2 + #.314 

yRAOOH + #-.976 XC

1.22E-12 2.33E-12 0.38 83

[a] Format of reaction listing: "=" separates reactants from products; "#number" indicates stoichiometric 

coefficient, "#coefficient {product list}" means that the stoichiometric coefficient is applied to all the 

products listed.

[b] Except as indicated, the rate constants are given by k(T) = A · (T/300)B· e-Ea/RT, where the units of k 

and A are cm3 molec-1s

-1

, Ea are kcal mol-1, T is oK, and R=0.0019872 kcal mol-1deg-1. The 

following special rate constant expressions are used:

Phot Set = name: The absorption cross sections and (if applicable) quantum yields for the photolysis 

reaction are given in Table A-3, where "name" indicates the photolysis set used. If a "qy=number" 

notation is given, the number given is the overall quantum yield, which is assumed to be 

wavelength independent.

Falloff: The rate constant as a function of temperature and pressure is calculated using k(T,M) = 

{k0(T)·[M]/[1 + k0(T)·[M]/kinf(T)]}· FZ, where Z = {1 + [log10{k0(T)·[M])/kinf(T)}/N]2}

-1

, [M] 

is the total pressure in molecules cm-3, F and N are as indicated on the table, and the temperature 

dependences of k0 and kinf are as indicated on the table.

k = k0+k3M(1+k3M/k2): The rate constant as a function of temperature and pressure is calculated 

using k(T,M) = k0(T) + k3(T)·[M] ·(1 + k3(T)·[M]/k2(T)), where [M] is the total bath gas (air) 

concentration in molecules cm-3, and the temperature dependences for k0, k2 and k3 are as 

indicated on the table.

k = k1 + k2 [M]: The rate constant as a function of temperature and pressure is calculated using 

k(T,M) = k1(T) + k2(T)·[M], where [M] is the total bath gas (air) concentration in molecules cm-3, 

and the temperature dependences for k1, and k2 are as indicated on the table.

Same K as Rxn xx: Uses the same rate constant as the reaction in the base mechanism with the same 

label.

[c] Footnotes documenting sources of rate constants and mechanisms are as follows.

1 Same as used or assumed in the SAPRC-99 mechanism (Carter, 2000a).

2 Rate constant or absorption coefficients and quantum yields based on NASA (2006) 

recommendation. Mechanism is also as recommended unless indicated by other footnotes.

3 Rate constant or absorption coefficients and quantum yields based on IUPAC (2006) 

recommendation. Mechanism is also as recommended unless indicated by other footnotes.

4 Absorption cross-sections and quantum yields as recommended for 294-298K. This gives an 

8% higher NO2 photolysis rate for direct overhead sunlight than the action spectrum used in 

SAPRC-99. Note that the net effect is to decrease rate constants for all other photolysis 

reactions by the same amount in environmental chamber simulations.

5 Separate recommendations are made for reactions with O2 and N2. Rate parameters used are 

derived to fit those calculated for a mixture of 20.95% O2 and 69.05% N2 over the 

temperature range of 250 - 350o K.
Table A-2 (continued)

151

6 See also Wahner et al (1998).

7 Absorption cross-sections recommended by NASA (2006) used, which are generally 

consistent with the IUPAC (2006) recommendations. The quantum yields for O

1D formation 

are from the IUPAC (2006) recommendation; the NASA (2006) recommendations are 

consistent with these at the <306 and 329-340 nm range, but the parameterization for deriving 

quantum yields between these ranges did not give reasonable values. The quantum yield for 

O1D production is assumed to be zero in the high wavelength ration (wavelength > 390 nm. 

The O

3

P quantum yields in the low wavelength regions are derived from the O

1D quantum 

yields assuming unit total quantum yield for both processes. The O

3

P quantum yields are 

assumed to be unity in the high wavelength region.

8 NASA (2006) absorption cross-sections used, which give much greater resolution than those 

recommended by IUPAC (2006). IUPAC data sheet recommends assuming unit quantum 

yield for NO + OH formation throughout the relevant wavelength range. The absorption cross 

sections are essentially the same as used in SAPRC-99, but SAPRC-99 has some formation of 

NO2 + H as well.

9 Rate expression from Golden et al (2003) and NASA (2006) for the reaction forming HNO3, 

using the NASA parameterization. The reaction forming HOONO is ignored, based on the 

assumption that it either decomposes or photolyzes back to the reactants. This expression is 

only slightly different than that given in the NASA (2003) recommendation, but gives a rate 

constant that is ~18% larger than that used in SAPRC-99 for ambient conditions.

10 Absorption cross sections used in SAPRC-99 are essentially the same as the NASA (2006) 

and IUPAC (2006) recommendations, so are not changed. Unit quantum yields are assumed.

11 Parameters derived to predict rate constants calculated from the temperature dependence 

expressions for the rate constants from the reverse reaction and the equilibrium constant as 

recommended by NASA (2006).

12 Absorption cross-sections from NASA (2006), and are essentially the same as used in 

SAPRC-99. Unit quantum yield assumed, as is also the case for SAPRC-99.

13 Measurements of the branching ratios vary, so the mechanism is uncertain. The SAPRC-99 

assignment is based on assuming the branching ratio is approximately in the middle of the 

range given in various evaluations, which is 0.6 - 1.0 for the OH-forming channel.

14 Methoxy radicals formed in the reaction assumed to react primarily with O2, forming HO2 + 

formaldehyde.

15 Recommendations are given for the total rate constant and the temperature dependence of the 

two competing processes. The kinetic parameters are derived so the calculated rate constants 

for the reactions agree with those derived from the recommended total rate constant and rate 

constant ratio over the temperature range of 270 - 330 K.

16 Recommendations are given for total rate constant and the competing process only. The 

kinetic parameters for this process were adjusted to minimize the sum of squares difference in 

rate constants between the rate constants calculated using the difference between the 

recommended rate constants and the calculated value, over the temperature range 270 - 330 K.

17 The species RO2C and RO2XC are used to represent the effects of peroxy radical reactions on 

NO, NO2, NO3, HO2, acyl peroxy radicals, and other peroxy radicals. RO2C is used to 

represent effects peroxy radicals that react with NO to form NO2 (and the corresponding 

alkoxy radical, whose ultimate products re represented by separate xPROD species discussed 

below), while RO2XC represents effects of peroxy radicals that react with NO but do not form 

NO (i.e., to form organic nitrates that are represented by a separate zRNO3 species discussed 

below). Separate xPROD, yROOH, and zRNO3 species are used to represent the other radical 
Table A-2 (continued)

152

and product species formed in peroxy radical reactions, which vary depending on the reactant 

and radicals formed. See separate footnotes given in conjunction with the reactions of these 

species, and the discussion in the text concerning the general method used to represent peroxy

radical reactions.

18 Rate constants used for generic peroxy radicals are based on recommendations for ethyl 

peroxy. See SAPRC-99 mechanism documentation (Carter, 2000) for a discussion of these 

peroxy radical operators.

19 Peroxy + peroxy reactions are assumed to proceed 1/2 the time forming two alkoxy radicals + 

O2, and the other half of the time by H-shift disproportionation reactions.

20 Rate expression from Bridier et al (1991), based on both NASA (2006) and IUPAC (2006) 

recommendations. Note that although this was intended to be the source of the rate constant 

used in the SAPRC-99 mechanism (Carter, 2000a), it was incorrectly implemented using N=1 

rather than N=1.61, as used by Bridier et al (1991). This amounts to about an 11% difference 

in the rate constants calculated for 298K and 1 atm. total pressure, but does not affect the 

equilibrium constant.

21 The branching ratio is based on an average of the values cited by IUPAC (2006). A third 

channel forming OH + O2 + CH3CO2 is assumed not to be important, though the data do not 

completely rule this out (IUPAC, 2005). Peroxyacetic acid (the co-product with O2) is 

represented by acetic acid to avoid the necessity of adding a new species in the mechanism for 

this reaction.

22 No recommendations available for this rate constant. Use the same rate constant as used for 

generic peroxy + NO3 reactions.

23 No recommendations available concerning the branching ratio. We assume that the major 

route is alkoxy radical formation, analogous to the route recommended to occur 90% of the 

time in the case of the reaction of acetyl peroxy with methyl peroxy.

24 Estimated assuming that the ratio of the rate constant ratio for the reaction with NO2 relative 

to reaction with NO is the same as for acetyl peroxy radicals at the high pressure limit. 

Temperature dependence parameters derived to fit rate constants calculated using 

k(RCO3+NO) x kinf(CCO3+NO2)/k(CCO3+NO) over the temperature range 270-330 K.

25 The high pressure limit for the recommended PPN decomposition rate expression is used. This 

is to be consistent with the assumption that the formation reaction is at the high pressure limit, 

and also because this model species is used to represent higher PAN analogues in addition to 

PPN. The recommended rate expression for PPN gives a 1 atm rate constant that is about 90% 

the high pressure limit.

26 Photolyses of higher PAN analogues are assumed to occur with same action spectrum and 

analogous mechanism as the photolysis of PAN.

27 Rate constants used for generic acyl peroxy radicals and generic higher PAN analogues based 

on those for R=C2H5. See SAPRC-99 documentation (Carter, 2000).

28 Reaction is assumed to be analogous to that for MECO3. Where applicable, the peroxy acid is 

represented by the corresponding acid to avoid adding a separate species to the mechanism to 

represent these products. Reaction with peroxy radicals is assumed to proceed primarily via 

alkoxy radical formation, the major (90%) pathway for the MECO3 + MEO2 reaction.

29 Rate constant expression based on the data of Kirchner et al (1992).

30 Rate parameters from Roberts and Bertman (1992), as used by Carter and Atkinson (1996).

31 This is added to avoid problems in the (generally unlikely) conditions where phenoxy radicals 

are formed when concentrations of both NO2 and HO2 are low. The rate constant used is that 

used in the SAPRC-99 mechanism, which is arbitrary and is such that this process becomes 
Table A-2 (continued)

153

significant only if [NO2] < ~3x10-6 ppm and [HO2] < 1x10-5ppm. The likely process is 

reaction with some VOC forming phenol and radicals, with the latter represented by RO2R.

32 The xPROD chemical operator species are used to represent the formation of radicals and 

products from alkoxy radicals formed in the reactions of peroxy radicals with NO, NO3, acyl 

peroxy radicals, and, in ~50% yields, with other peroxy radicals. These products are not 

formed when peroxy radicals react with HO2, and, in ~50% yields, with other peroxy radicals, 

since those reactions are assumed not to form alkoxy radicals, but instead form 

hydroperoxides or H-shift disproportion products that are represented by separate yROOH 

chemical operator species, discussed in a separate footnote. The reactions of peroxy radicals 

with other peroxy radicals are assumed to form alkoxy radicals 50% of the time, so the 

products from alkoxy radical reactions are represented as being formed in 50% yields in these 

reactions. The consumption and products formed from these species can be represented in 

several ways. The most straightforward method is to include a reaction for each of the types of 

peroxy radical reactions, as follows:

xPROD + NO  NO + PROD

xPROD + HO2  HO2

xPROD + NO3  NO3 + PROD

xPROD + MECO3  MECO3 + PROD (& similar reactions for RCO3, BZCO3, and 

MACO3)

xPROD + MEO2  MEO2 + 1/2 PROD

xPROD + RO2C  RO2C + 1/2 PROD (& a similar reaction for RO2XC)

where "PROD" represents the product species for the operator (e.g., HO2 for xHO2). The rate 

constants for these reactions should be the same as the rate constant for the corresponding 

reactions of RO2C or RO2XC. This is a somewhat cumbersome method because it requires 9 

reactions for each of the many xPROD species. An alternative method, implemented in this 

table, uses the coefficient "RO2RO" to determine the rate of formation of the product species 

and "RO2XRO" to represent processes where the product is not formed. These are calculated 

as follows, where the k(RO2+..)'s refer to the rate constants for the reactions of RO2C or 

RO2XC with the indicated reactant.

RO2RO = k(RO2+NO)[NO] + k(RO2+NO3)[NO3] + k(RO2+MECO3){[MECO3]+[RCO3]+ 

[BZCO3]+[MACO3]) + 0.5 k(RO2+MEO2)[MEO2] + 0.5 k(RO2+RO2) 

{[RO2C]+[RO2XC])

RO2XRO = k(RO2+HO2)[HO2] + 0.5 k(RO2+MEO2)[MEO2] + 0.5 k(RO2+RO2){[RO2C]+ 

[RO2XC])

The steady state approximation must be used for these operators when this representation is 

used, and the operators must not be allowed to be diluted or transported.

33 The 298K rate constant is as estimated by IUPAC (2006). The temperature dependence used 

in the SAPRC-99 mechanism is consistent with this, so is retained here.

34 This reaction is not believed to be important under atmospheric conditions or in the conditions 

of the chamber experiments used for mechanism evaluation. The adduct is believed to rapidly 

rearrange to HOCH2OO·, which can react with NO to ultimately form NO2 and formic acid, or 

decompose back to formaldehyde + HO2, resulting in no net reaction. Based on the rate 

constants for the HOCH2OO· decomposition recommended by IUPAC (2006) and the 

expected peroxy + NO rate constant, the reaction with NO is expected to be negligible unless 

NO is so high that HO2 levels are suppressed, so the decomposition, resulting in no net 

reaction, is expected to dominate. Sensitivity calculations with versions of the mechanism

incorporating this reaction confirmed the negligible impact of this process. 

35 Mechanism of propionaldehde used for RCHO. IUPAC (2006) recommendation used for total 
Table A-2 (continued)

154

rate constant. No useful recommendation given for mechanism.

36 Mechanism based on estimated relative rates of reactions at various positions and estimated 

rate constants or rate constant ratios for reactions of the various radicals formed, derived using

current SAPRC mechanism generation system. For this reaction the generated mechanism 

should be essentially the same as the version developed with the SAPRC-99 mechanism 

(Carter, 2000a).

37 The absorption cross sections recommended by IUPAC (2006) are the same as used in the 

SAPRC-99 mechanism. There is a discrepancy in the quantum yields at higher wavelengths 

from recent measurements from Chen and Ziu (2001), which indicate no falloff at the higher 

wavelengths, and earlier measurements from Heicklen et al (1986) that indicated a falloff in 

quantum yields and was the basis of previous recommendation and the propionaldehyde 

photolysis rates used in the SAPRC-99 mechanism (Carter, 2000a). IUPAC (2006) and NASA 

(2006) make no recommendations in this regard. We assume that the earlier values are more 

representative of atmospheric conditions because they were based on measurements made in 

air while the more recent measurements were in N2, and the possibility that the falloff could be 

due to quenching by O2, and because the photolysis rates obtained are more consistent with 

those measured in the Euphore chamber (Wirtz et al, 1999). Therefore, the earlier quantum 

yields, as used in the SAPRC-99 mechanism, are retained.

38 298K rate constant is that recommended by IUPAC (2006) for propionaldehyde. Temperature 

dependence estimated by assuming this reaction has same A factor as reaction of NO3 with 

acetaldehyde.

39 Temperature-dependent parameters derived to give best fits to the IUPAC (2006)-

recommended temperature dependence expression for the temperature range 270-330 K. 

These parameters give a good estimate of the recommended rate constant at ~300o K, but 

underestimate the recommended rate constants by about 2% at both ends of this temperature 

range.

40 Absorption cross sections are for T=298oK. Quantum yields are calculated for 1 atm and 

T=298oK using the complex expression recommended by IUPAC (2006) and NASA (2006). 

Separate recommendations are given for temperature, pressure, and wavelength-dependent 

quantum yields for formation of CO and formation of CH3CO, and the calculated fraction of 

the CO formation process relative to total fragmentation to radicals ranges from 35% to 52% 

for zenith angle of 0 to 80, respectively. The ratios for the indoor light sources used in the 

chamber experiments used for evaluating the mechanism are in this range. Rather than have 

two separate photolysis processes in the mechanism, a wavelength-independent ratio of 48% is 

assumed, which represents the weighed average of these values. However, using the quantum 

yields derived in this way gives photolysis rates that are about 1.6 times higher than used in 

SAPRC-99 and significantly overpredicts reactivity in acetone incremental reactivity 

experiments. In order to remove this bias, it is necessary to reduce the photolysis rates by 

about a factor of 2, i.e., assume the quantum yields are 1/2 the values derived using the 

recommended method. This inconsistency between the laboratory data and the chamber 

experiments need to be evaluated. However, the quantum yields that give the better fits to the 

chamber data are used because they are a better approximation of atmospheric conditions.

41 Absorption cross-sections from IUPAC (2006) recommendation, but are essentially the same 

as used in SAPRC-99. The IUPAC (2006)-recommended overall quantum yield is 0.24 (with 

no recommendation given for wavelength dependence of quantum yields), but this results in a 

bias towards overpredicting reactivity in MEK incremental reactivity experiments. The data 

are better fit using an overall quantum yield of 0.175, which is slightly higher than the 0.15 

value used in the SAPRC-99 mechanism, based on simulations of the same experiments.
Table A-2 (continued)

155

42 The reaction would involve the eventual formation of HO2 + CO2 regardless of which 

hydrogen were abstracted in the initial reaction.

43 Branching ratio used for formation of ·CH2OOH vs. CH3OO· is as recommended by NASA 

(2006). ·CH2OOH is assumed to rapidly decompose to formaldehyde + OH.

44 Mechanism generation system updated to predict the NASA (2006) recommended rate 

constant and branching ratio for the reaction of OH with methyl hydroperoxide. The generated 

mechanism for n-propyl hydroperoxide incorporates the substituent effects for the -OOH 

group derived from this rate constant and branching ratio.

45 Mechanism for ROOH based on estimated reactions for n-propyl hydroperoxide. Photolysis 

and rate of reaction of OH at OOH assumed to occur at same rate as for methyl 

hydroperoxide.

46 Mechanism for R6OOH based on estimated reactions for 3-hexyl hydroperoxide. Photolysis 

and rate of reaction of OH at OOH assumed to occur at same rate as for methyl 

hydroperoxide.

47 Mechanism for RAOOH is based on estimated reactions of two isomers expected to be formed 

in the m-xylene system. Mechanism derived using the mechanism generation system based on 

estimated reactions at various positions, and assumptions for the major process for some 

alkoxy radical reactions that could not be estimated using the current system. Photolysis and 

rates of reaction of OH at OOH assumed to occur at the same rate as for methyl 

hydroperoxide.

48 Absorption cross sections used are those given by Volkamer et al (2005), which supercede the 

values of Plum et al (1983) used in previous recommendations. For wavelengths up to 350 nm, 

the quantum yields for radical production are based on those of Zhu et al (1996), which are 

consistent with the data of Langford and Moore (1984). The quantum yields for formaldehyde 

+ H2 production are derived based on assuming a total quantum yield of 1 in this wavelength 

region. For the higher wavelength region, the decline in quantum yields as a function of 

wavelength are derived to give photolysis rates, relative to those for NO2, that are consistent 

with the data of Klotz et al (2000) based on assuming solar spectral distributions with zenith 

angles between 0 and 40 degrees, and that are also consistent with the formaldehyde yields, 

relative to total photolysis, of 13%, as given by Plum et al (1983). In both cases, the quantum 

yield is assumed to decline exponentially as a function of wavelength below 350 nm, with the 

decay rate adjusted to give the photolysis rate consistent with the data referenced above.

49 Mechanism based on branching ratios for subsequent reactions of the radicals formed as given 

by IUPAC (2006) for 1 atm air at 298oK.

50 No data available for the kinetics of this reaction. Rate parameters used in SAPRC-99 used. 

See Carter (2000) for method used to estimate rate constant. HCO(CO)OO. and RCO(CO)OO 

are represented by the lumped higher acyl peroxy species RCO3.

51 Recommended cross sections are essentially the same as used in SAPRC-99. Quantum yields 

calculated using the temperature- and wavelength-dependence expression recommended by 

IUPAC (2006) for 760 torr N2 give an overall photolysis rate, relative to NO2, for ambient 

photolysis which are lower than those reported by Klotz et al (2003) for the Euphore outdoor 

chamber. However, if the quantum yields are calculated for a pressure of 472 torr, the 

calculated photolysis rate relative to NO2 for ambient conditions agree with the data of Klotz 

et al (2003). Therefore, this adjustment is adopted for the quantum yields used for this 

mechanism.

52 The evaluations give no recommendations for the photolysis of biacetyl. The absorption cross 

sections used are those from Plum et al (1983), as used in the SAPRC-99 mechanism. 

Quantum yields calculated using the IUPAC (2006)-recommended expression for the pressure 
Table A-2 (continued)

156

and wavelength-dependence quantum yields for methyl glyoxal, but with the effective 

pressure adjusted so the photolysis rate, relative to that for NO2, under ambient conditions is 

consistent with that measured by Klotz et al (2000) in the Euphore outdoor chamber.

53 Rate constant expression as recommended by Calvert et al (2002) for o-cresol.

54 "CRES" is used to represent phenol and cresols. (Phenol was represented separately in 

SAPRC-99 but is lumped with cresols in this mechanism because the lumping had no 

significant effect on model simulations and the mechanisms of both are highly uncertain and 

approximate.) Available data (Berndt and Boge, 2003 and Olariu et al 2002) indicate that 

dihydroxy phenol or cresol formation occurs ~60-80% of the time, and kinetic data cited by 

Berndt and Boge (2003) suggest that in the case of phenol under atmospheric conditions OH 

addition occurs ~75-80% of the time, with phenoxy formation occurring the remainder of the 

time. This suggests that dihydroxybenzene formation (with HO2 as the co-product) is the 

major fate of the OH addition reaction. However, this mechanism cannot simulate results of 

the cresol - NOx air chamber experiments. In order to simulate the reactivity in those 

experiments, it is necessary to assume additional NO to NO2 conversions occur, and it is also 

necessary to some photoreactive product, such as methyl glyoxal, is also formed. In view of 

the inconsistency between chamber and laboratory data concerning this reaction, we retain the 

parameterization used in the SAPRC-99 mechanism (Carter, 2000), which was found to 

perform the best in simulating the chamber data, after some minor adjustments to optimize fits 

to the data with the current mechanism. This is consistent with the laboratory data in assuming 

~20% phenoxy radical formation, but does not appear to be consistent with other laboratory 

data in assuming an additional NO to NO2 conversion is occurring. The photoreactive 

product(s) are represented by methyl glyoxal, which gives reasonable simulations of the 

observed PAN yields in the cresol experiments (Carter, 2000).

55 Rate constant is in the range cited by Barnes (2006) for various nitrocresols. Reaction is 

assumed to occur via abstraction of H from OH, analogous to pathway in the phenol and 

cresol + OH reactions that occur with similar rates.

56 Photolysis rate forming HONO, relative to the photolysis rate of NO2, based on the data of 

Bejan et al (2006) for 2-nitrophenol and various methyl substituted 2-nitrophenols. The coproducts are unknown, and are assumed to go mainly into the particle phase and its gas-phase 

reactivity is assumed not to be significant. Loss by other photolysis processes might be 

significant, but are ignored.

57 Nitrophenols were found to have lifetimes relative to photolysis in the Euphore chamber of 1-

2 hours (Barnes, private communication, 2007). A photolysis rate relative to NO2 of 0.015 

corresponds approximately to this range. The products formed are unknown, but based on the 

data of Bejan et al (2006) it is apparent that NO2 formation is not important and that HONO 

formation represents only about 10% of this process. We assume that the products are 

unreactive.

58 As with SAPRC-99, is assumed that all the reaction is at the -CHO group, and that addition to 

the ring is negligible.

59 Rate constant is as recommended or tabulated by Atkinson and Arey (2003).

60 Absorption cross-sections recommended by Calvert et al (2002). Overall quantum yield based 

on that of SAPRC-99 mechanism, which was adjusted to approximately fit the rate of 

consumption of benzaldehyde measured in chamber experiments. However, the new 

absorption cross sections result in a ~17% decrease in the solar photolysis rate for 

benzaldehyde, so the overall quantum yield is adjusted upward by the same factor to yield the 

same overall photodecomposition rate. The mechanism is the same as in SAPRC-99, which is 

based on the fact that the products are unknown but are apparently unreactive, and not 
Table A-2 (continued)

157

benzene.

61 The 298oK rate constant recommended by Atkinson (1994). Temperature dependence 

estimated by assuming the reaction has the same A factor as the reaction of NO3 with 

acetaldehyde. This gives the same 298oK rate constant but a slightly different temperature 

dependence than used in SAPRC-99.

62 AFG1 and AFG2 are used to represent the photoreactive monounsaturated dialdehyde or 

aldehyde-ketone aromatic ring fragmentation products. Their mechanistic parameters are 

based on those for 2-butene 1,4-dial (10%), 2-methyl-2-butene-1,4-dial (21%), 4-oxo-2-

petenal (37%), and 2-methyl-4-oxo-2-pentenal (32%). The action spectrum for the photolysis 

reactions of both species is also based on weighted averages of action spectra assigned to 

those species. The weighting factors used for each are based on the relative yields 

monounsaturated dialdehydes or aldehyde-ketones estimated for toluene and the di- and trimethylbenzene isomers, each weighed equally, with 2,3-dimethyl-2-butene-1,4-dial 

represented by 2-methyl-2-butene-1,4-dial, and 3-methyl-4-oxo-2-penetnal and 2,3-dimethyl4-oxo-2-pentenal represented by 2-methyl-4-oxo-2-pentenal. AFG1 is used to represent those 

compounds (or portions of the mechanisms) that photolyze to form radicals, while AFG2 is 

used to represent those which photolyze to form non-radical products, and each have the same 

OH and O3 mechanism and overall action spectrum.

63 The mechanisms for the radical formation photolysis for AFG1 is based on that derived for the 

radical formation photolysis of the species used to derive the mechanistic parameters for the 

OH and O3 reactions. The stable species formed in the photolysis of AFG2 are represented by 

PROD2.

64 AFG3 is used to represent the diunsaturated dicarbonyl products and also the monounsaturated 

diketone aromatic ring fragmentation products, which are assumed to have relatively low 

photoreactivity. There mechanisms are based on those derived for the diunsaturated 

dicarbonyl products 3-methyl 2,4-hexene-1,6-dial (54%), 6-oxo-2,4-heptadienal (66%), and 

3,5-octadien-2,7-dione (6%). The weighting factors used are based on estimated diunsaturated 

dicarbonyls for toluene and the di- and tri-methylbenzene isomers, each weighed equally, with 

2,4-hexene-1,6-dial representing all dialdehydes, 3,5-octadien-2,7-dione representing 

aldehyde-ketones, and 3,5-octadien-2,7-dione representing the diketones. Although this model 

species is also used to represent the monounsaturated diketone products, which are also 

assumed to be relatively unphotoreactive, they are formed by only a few isomers and their 

parameters are not used to derive those used for AFG3. (Representing them explicitly does not 

yield significantly improved simulations of p-xylene, and 1,2,4-trimethylbenzene, the only 

compounds with chamber data where such products are predicted to be formed.)

65 Except as indicated in other footnotes, the mechanism is as given by Carter (1996), based on 

the detailed mechanism of Carter and Atkinson (1996). (The rate constant and mechanism is 

unchanged from SAPRC-99 if footnote "1" is also given).

66 IUPAC (2006) recommendation of rate constant at 298oK used. Temperature dependence is 

estimated using the estimated A factor given used in the SAPRC-99 mechanism, based on the 

estimate of Carter and Atkinson (1996).

67 Absorption cross sections recommended by IUPAC (2006) used. No recommendations given 

for quantum yield. The quantum yields were derived using the pressure and wavelengthdependent expression given by IUPAC (2006) for MVK, with the total pressure adjusted so 

that the radical forming photolysis rates for the chamber experiments are the same as those 

derived by Carter and Atkinson (1996) to fit the chamber experiments with methacrolein.

68 Absorption cross sections recommended by IUPAC (2006) used. IUPAC (2006) also gives 

recommendations for quantum yields for total photodecomposition as a function of 
Table A-2 (continued)

158

wavelength and pressure, and recommend assuming 60% forms propene + CO and the 

remainder involves radical formation. However, this recommendation gives photolysis rates 

for radical formation that are significantly higher than those found to fit chamber data for 

MVK (Carter and Atkinson, 1996). Using an effective pressure of 5 atmospheres gives radical 

formation photolysis that is consistent with modeling the chamber data, and is used in this 

mechanism. This is not inconsistent with the IUPAC (2006) recommendations because they 

stated that their recommended quantum yields should be considered to be upper limits. It is 

assumed that the radical formation process involves formation of CH3 + CH2=CHCO·, as was 

assumed in the SAPRC-99 mechanism.

69 Consistent with the assumption in the SAPRC-99 mechanism, all species represented by 

ISOPROD are assumed to have the same action spectrum for photolysis as used for acrolein. 

As indicated in the footnotes for the methacrolein photolysis reaction, some modifications 

were made to the methacrolein action spectrum but the photolysis rates for conditions of 

chamber experiments are essentially the same as used in SAPRC-99. The other aspects of this 

reaction are not changed.

70 PROD2 is used to represent the more reactive non-aldehyde organic products formed in the 

photooxidations of various VOCs. As with SAPRC-99, its mechanism is based on those 

derived for representative product compounds that are represented by PROD2, which were 

chosen to be CH3C(O)CH2CH2CH2OH, CH3C(O)CH2CH(CH3)CH2OH, CH3CH2C(O)CH2-

CH2CH(CH3)OH, CH3CH2C(O)CH2CH2CH(OH)CH2CH3, and CH3CH2CH2CH(OH)CH2-

CH2C(O)CH2CH3 (Carter, 2000a). The rate constants and mechanisms for these compounds 

(designated PROD2-1 through 5, respectively) were derived using the mechanism generation 

system, and are given in Table B-4 in Appendix B. The mechanisms for PROD2 were derived 

by weighing those for each of these representative compounds equally.

71 Absorption cross-sections for methyl ethyl ketone used for general ketone photolysis, with 

quantum yields declining monotonically with carbon number (see discussion of general ketone 

photolysis elsewhere in this report). Overall quantum yields and mechanisms averages for the 

compounds used to derive the mechanism for PROD2.

72 As with SAPRC-99, the mechanism for the lumped organic nitrate product species is based on 

those derived for 6 compounds chosen to be representative of thee compounds, specifically 

CH3CH2CH(CH3)ONO2, CH3CH(OH)CH2CH2CH2ONO2, CH3CH2CH(CH3)CH(CH3)ONO2, 

CH3CH2CH2CH2CH2CH(ONO2)CH2OH, CH3CH2C(CH3)(ONO2)CH2CH(CH3)CH3, and CH3-

CH2CH2CH2CH2CH2CH2CH(ONO2)CH2CH3 (RNO3-1 through 6) (Carter, 2000a). The rate 

constants and mechanisms for these compounds were derived using the current mechanism 

generation system, which should be similar to those predicted using the SAPRC-99 

mechanism generation system documented by Carter (2000a). The mechanisms for RNO3 

were derived by weighing those for each of these representative compounds equally.

73 Absorption cross section for isopropyl nitrate as given by IUPAC (2006) used, assuming unit 

quantum yields. This is the same as used for RNO3 in SAPRC-99.

74 The zRNO3 chemical operator species is used to represent the formation organic nitrates 

formed when peroxy radicals react with NO, or formation of radicals and products from

alkoxy radicals formed in the reactions of peroxy radicals with NO3, acyl peroxy radicals, and 

(in ~50% yields) with other peroxy radicals. These products are not formed when peroxy 

radicals react with HO2 and (in the other ~50% of the time) with other peroxy radicals, since 

those reactions are assumed not form organic nitrates or alkoxy radicals, but instead form

hydroperoxides or H-shift disproportion products that are represented by separate yROOH 

chemical operator species, discussed in a separate footnote. At present the mechanism has 

only one zRNO3 operator to correspond to the single lumped organic nitrate model species, 

but other such operators can be added if it is desired to have separate organic nitrate model 
Table A-2 (continued)

159

species, such as, for example, those to represent semi-volatile organic nitrates that may 

contribute to SOA. In the case of zRNO3, the products resulting if alkoxy radicals are formed 

in the RCO3 or RO2 reactions would depend on reactant and individual radicals, and are 

approximated by PROD2 and HO2 (as might occur following the reaction of a peroxy radical 

with O2 to form HO2 and a ketone species). As with the xPROD species, the consumption and 

products formed from these species can be represented in several ways, with the most 

straightforward method being to include a reaction for each of the types of peroxy radical 

reactions, as follows:

zRNO3 + NO  NO + RNO3

zRNO3 + HO2  HO2

zRNO3 + NO3  NO3 + PROD2 + HO2

zRNO3 + MECO3  MECO3 + PROD2 + HO2 (& similar reactions for RCO3, 

BZCO3, and MACO3)

zRNO3 + MEO2  MEO2 + 1/2 {PROD2 + HO2}

zRNO3 + RO2C  RO2C + 1/2 {PROD2 + HO2} (& a similar reaction for RO2XC)

The rate constants for these reactions should be the same as the rate constant for the 

corresponding reactions of RO2C or RO2XC. As with xPROD, an alternative method, 

requiring fewer reactions, is implemented in this table. In this case, the coefficient "RO2NO" 

is used to determine the rate of formation of organic nitrates, "RO22NN" is used to determine 

the rate of formation of the alkoxy radical products, and "RO2XRO" is used to represent 

processes where these products are is not formed, and is the same as used for xPROD. These 

are calculated as follows, where the k(RO2+..)'s refer to the rate constants for the reactions of 

RO2C or RO2XC with the indicated reactant.

RO2NO = k(RO2+NO)[NO]

RO22NN = k(RO2+NO3)[NO3] + k(RO2+MECO3){[MECO3]+[RCO3]+[BZCO3]+ 

[MACO3]) + 0.5 k(RO2+MEO2)[MEO2] + 0.5 k(RO2+RO2){[RO2C]+ 

[RO2XC])

RO2XRO = k(RO2+HO2)[HO2] + 0.5 k(RO2+MEO2)[MEO2] + 0.5 k(RO2+RO2){[RO2C]+ 

[RO2XC]) (same as used for xPROD)

The steady state approximation must be used for these operators when this representation is 

used, and the operators must not be allowed to be diluted or transported.

75 The yROOH chemical operator species is used to represent the formation of organic 

hydroperoxides formed with peroxy radicals react with HO2, or of H-shift disproportionation 

products formed when peroxy radicals react (in 50% yields) with other peroxy radicals. Note 

that the products formed when peroxy radicals react to form alkoxy radicals or organic nitrates 

(in the NO reaction) are represented using separate xPROD or zRNO3 species, and together 

these three types of operators represent all the products and radicals formed. Separate such 

yROOH species are used to represent formation of hydroperoxides or H-shift disproportion 

products in different molecular weight ranges or volatilities, and more can be added as needed 

for appropriate predictions of SOA formation. The hydroperoxide formed in the HO2 reaction 

is represented by either ROOH, R6OOH, or RAOOH, and the H-shift disproportion products 

are represented by either MEK (for yROOH) or PROD2 (for the others). As with the xPROD 

and zRNO3 species, the consumption and products formed from these species can be 

represented in several ways, with the most straightforward method being to include a reaction 

for each of the types of peroxy radical reactions, as follows for yROOH (the reactions for the 

other two are analogous).

yROOH + NO  NO

yROOH + HO2  HO2 + ROOH
Table A-2 (continued)

160

yROOH + NO3  NO3

yROOH + MECO3  MECO3 (& similar reactions for RCO3, BZCO3, and 

MACO3)

yROOH + MEO2  MEO2 + 1/2 MEK

yROOH + RO2C  RO2C + 1/2 MEK (& a similar reaction for RO2XC)

The rate constants for these reactions should be the same as the rate constant for the 

corresponding reactions of RO2C or RO2XC. As with the other operators, an alternative 

method, requiring fewer reactions, is implemented in this table. In this case, the coefficient 

"RO2HO2" is used to determine the rate of formation of organic hydroperoxides, 

"RO2RO2M" to determine the rate of formation of H-shift disproportion products, and 

"RO2RO" is used to represent processes where these products are is not formed. Note that the 

latter is the same as the coefficient that is used to represent the formation products from the 

xPROD species. These are calculated as follows, where the k(RO2+..)'s refer to the rate 

constants for the reactions of RO2C or RO2XC with the indicated reactant.

RO2HO2 = k(RO2+HO2)[HO2]

RO2RO2M = 0.5 k(RO2+RO2){[RO2C]+ [RO2XC])

RO2RO = k(RO2+NO)[NO] + k(RO2+NO3)[NO3] + k(RO2+MECO3){[MECO3]+[RCO3]+ 

[BZCO3]+[MACO3]) + 0.5 k(RO2+MEO2) [MEO2] + 0.5 k(RO2+RO2) 

{[RO2C]+[RO2XC])

The steady state approximation must be used for these operators when this representation is 

used, and the operators must not be allowed to be diluted or transported.

76 The mechanism is the same as used in SAPRC-99, but the rate constant was updated based on 

a more recent evaluation.

77 Criegee biradical stabilization yield as recommended by Atkinson (1997) and IUPAC (2006). 

OH yield of 16% used based on recommendation of IUPAC (2006), which is higher than the 

12% yield recommended by Atkinson (1997). The yields of the other decomposition pathways 

based on Atkinson (1997) recommendations except they were reduced by 8% to account for 

the higher OH yield of the IUPAC (2006) recommendation.

78 Radical fragmentation distribution as recommended by Calvert et al, (2000), ignoring H2 + 

ketene route. Although Calvert et al. (2000) recommends assuming 95% fragmentation, it is 

necessary to assume ~20% stabilization to remove biases in model simulations of ethene. This 

is consistent with the need to assume more-than-recommended stabilization in the analogous 

reaction of propene to remove biases in model simulations of propene experiments. However, 

this is somewhat lower than the ~50% stabilization used in the SAPRC-99 mechanism to 

remove biases in simulations of the ethene experiments.

79 Rate constant expression as recommended by Calvert et al (2000)

80 Acetylene is added as an explicitly represented compound in the current base mechanism 

because of its relatively large emissions and the fact that it is not well represented by other 

lumped species in the mechanism.

81 The mechanism is derived as discussed by Carter et al (1997c), based in part on the data of 

Hatakeyama et al (1986) and in part of adjustments to fit chamber data, except that in order to 

fit chamber data with the current mechanism it is necessary to assume that all of the initial 

reaction with OH results in the formation of HOCH=CH. radicals.

82 The mechanism is based on assuming the initially formed adduct rearranges to form excited 

HCOCHOO Crigiee biradicals. The subsequent reaction of this excited biradical is unknown, 

but it is assumed that decomposition is dominant, forming CO + HCO + OH half the time and 

HCO2· + HCO the other half.
Table A-2 (continued)

161

83 Benzene is added as an explicitly represented compound in the current base mechanism 

because of its non-negligible emissions and the fact that it is not well represented by the other 

lumped aromatic species in the mechanism. The rate constant expression is as recommended 

by Atkinson and Arey (2003). The mechanism employs the general mechanism formulation 

used for aromatics in this version of the mechanism. The yield of phenol (represented by 

CRES) is the average of values of Berndt and Boge (2006) and Volkamer et al (2002). This is 

significantly higher than the values used in the SAPRC-99 mechanism (Carter, 2000a). The

glyoxal yield is as determined by Berndt and Boge (2006), which is reasonably consistent with 

previous studies. AFG1 and AFG2 represent the co-product(s) formed with the alphadicarbonyls, which react with the same mechanism except that AFG1 is highly photoreactive 

and AFG2 is not, and with their relative yields adjusted to fit ozone reactivity results in the 

benzene - NOx chamber experiments. AFG3 is used to represent ring fragmentation products 

not involving alpha-dicarbonyl formation, which is assumed to involve formation of OH 

without NO to NO2 conversions. The yields of OH, HO2, and RO2R are derived as used for 

general aromatics mechanisms, and are equal to the yields of AFG3, phenol, and total alphadicarbonyls, respectively.
162

Table A-3. Absorption cross-sections and quantum yields for the all photolysis reactions in the base 

mechanism. (Available in electronic form only)

Because of the size of this table, it is only available in as 

supplementary material in electronic form. See Appendix D.

Table A-4. List of model species used in the base chlorine SAPRC-07 mechanism.

Name Description

Active Inorganic Species.

CL2 Chlorine molecules

CLNO ClNO

CLONO ClONO

CLNO2 ClNO2

CLONO2 ClONO2

HOCL HOCl

HCL Hydrochloric acid

Active Radical Species and Operators.

CL Chlorine atoms

CLO ClO. Radicals

Steady state operators used to represent radical or product formation in peroxy radical reactions.

xCL Formation of Cl radicals from alkoxy radicals formed in peroxy radical reactions with NO 

and NO3 (100% yields) and RO2 (50% yields)

xCLCCHO As above, but for CLCCHO

xCLACET As above, but for CLACET

Active Organic Product Species

CLCCHO Chloroacetaldehyde (and other alpha-chloro aldehydes that are assumed to be similarly 

photoreactive)

CLACET Chloroacetone (and other alpha-chloro ketones that are assumed to be similarly 

photoreactive)

Low Reactivity Compounds Represented as Unreactive

CLCHO Formyl Chloride
163

Table A-5. Listing of reactions and rate parameters added to represent the reactions of chlorine 

species in the SAPRC-07 mechanism.

Label Reaction and Products [a] Rate Parameters [b] Refs & 

k(298) A Ea B Notes [c]

Base Chlorine Mechanism

CI01 CL2 + HV = #2 CL Phot Set= CL2 1

CL + O2 + M = CLO2. + M (Ignored) 3

CLO2. + M = CL + O2 + M (Ignored) 3

CI02 CL + NO + M = CLNO + M 7.60e-32 7.60e-32 0.00 -1.80 2

CI03 CLNO + HV = CL + NO Phot Set= CLNO-06 1

CI04 CL + NO2 = CLONO 1.60e-11 Falloff, F=0.60, N=1.00 2

0: 1.30e-30 0.00 -2.00

inf: 1.00e-10 0.00 -1.00

CI05 CL + NO2 = CLNO2 3.52e-12 Falloff, F=0.60, N=1.00 2

0: 1.80e-31 0.00 -2.00

inf: 1.00e-10 0.00 -1.00

CI06 CLONO + HV = CL + NO2 Phot Set= CLONO 1

CI07 CLNO2 + HV = CL + NO2 Phot Set= CLNO2 1

CI08 CL + HO2 = HCL + O2 3.44e-11 3.44e-11 0.00 -0.56 1,4

CI09 CL + HO2 = CLO + OH 9.41e-12 9.41e-12 0.00 2.10 4

CI10 CL + O3 = CLO + O2 1.22e-11 2.80e-11 0.50 1

CI11 CL + NO3 = CLO + NO2 2.40e-11 1

CI12 CLO + NO = CL + NO2 1.66e-11 6.20e-12 -0.59 1

CI13 CLO + NO2 = CLONO2 2.29e-12 Falloff, F=0.60, N=1.00 2

0: 1.80e-31 0.00 -3.40

inf: 1.50e-11 0.00 -1.90

CI14 CLONO2 + HV = CLO + NO2 Phot Set= CLONO2-1 1

CI15 CLONO2 + HV = CL + NO3 Phot Set= CLONO2-2 1

CI16 CLONO2 = CLO + NO2 4.12e-4 Falloff, F=0.60, N=1.00 5

0: 4.48e-5 24.90 -1.00

inf: 3.71e+15 24.90 3.50

CI17 CL + CLONO2 = CL2 + NO3 1.01e-11 6.20e-12 -0.29 1

CI18 CLO + HO2 = HOCL + O2 6.83e-12 2.20e-12 -0.68 1

CI19 HOCL + HV = OH + CL Phot Set= HOCL-06 1

CI20 CLO + CLO = #.29 CL2 + #1.42 CL + O2 1.82e-14 1.25e-11 3.89 6

CI21 OH + HCL = H2O + CL 7.90e-13 1.70e-12 0.46 1

CI22 CL + H2 = HCL + HO2 1.77e-14 3.90e-11 4.59 1

Chlorine reactions with common organic products

CP01 HCHO + CL = HCL + HO2 + CO 7.33e-11 8.10e-11 0.06 1

CP02 CCHO + CL = HCL + MECO3 8.00e-11 8.00e-11 1

CP03 MEOH + CL = HCL + HCHO + HO2 5.50e-11 5.50e-11 0.00 1
Table A-5 (continued)

164

Label Reaction and Products [a] Rate Parameters [b] Refs & 

k(298) A Ea B Notes [c]

CP04 RCHO + CL = HCL + #.9 RCO3 + #.1 {RO2C 

+ xCCHO + xCO + xHO2 + yROOH}

1.23e-10 7

CP05 ACET + CL = HCL + RO2C + xHCHO + 

xMECO3 + yROOH

2.75e-12 7.70e-11 1.99 2

CP06 MEK + CL = HCL + #.975 RO2C + #.039 

RO2XC + #.039 zRNO3 + #.84 xHO2 + #.085 

xMECO3 + #.036 xRCO3 + #.065 xHCHO + 

#.07 xCCHO + #.84 xRCHO + yROOH + 

#.763 XC

3.60e-11 1,8

CP07 RNO3 + CL = HCL + #.038 NO2 + #.055 HO2 

+ #1.282 RO2C + #.202 RO2XC + #.202 

zRNO3 + #.009 RCHO + #.018 MEK + #.012 

PROD2 + #.055 RNO3 + #.159 xNO2 + #.547 

xHO2 + #.045 xHCHO + #.300 xCCHO + 

#.020 xRCHO + #.003 xACET + #.041 xMEK 

+ #.046 xPROD2 + #.547 xRNO3 + #.908 

yR6OOH + #.201 XN + #-.149 XC

1.92e-10 8,9

CP08 PROD2 + CL = HCL + #.314 HO2 + #.680 

RO2C + #.116 RO2XC + #.116 zRNO3 + 

#.198 RCHO + #.116 PROD2 + #.541 xHO2 + 

#.007 xMECO3 + #.022 xRCO3 + #.237 

xHCHO + #.109 xCCHO + #.591 xRCHO + 

#.051 xMEK + #.040 xPROD2 + #.686 

yR6OOH + #1.262 XC

2.00e-10 8,9

CP09 GLY + CL = HCL + #.63 HO2 + #1.26 CO + 

#.37 RCO3 + #-.37 XC

7.33e-11 8.10e-11 0.06 10

CP10 MGLY + CL = HCL + CO + MECO3 8.00e-11 10

CP11 CRES + CL = HCL + xHO2 + xBALD + 

yR6OOH

6.20e-11 11

CP12 BALD + CL = HCL + BZCO3 8.00e-11 12

CP13 ROOH + CL = HCL + #.414 OH + #.588 

RO2C + #.414 RCHO + #.104 xOH + #.482 

xHO2 + #.106 xHCHO + #.104 xCCHO + 

#.197 xRCHO + #.285 xMEK + #.586 yROOH 

+ #-0.287 XC

1.66e-10 8

CP14 R6OOH + CL = HCL + #.145 OH + #1.078 

RO2C + #.117 {RO2XC + zRNO3} + #.145 

PROD2 + #.502 xOH + #.237 xHO2 + #.186 

xCCHO + #.676 xRCHO + #.28 xPROD2 + 

#.855 yR6OOH + #.348 XC

3.00e-10 8
Table A-5 (continued)

165

Label Reaction and Products [a] Rate Parameters [b] Refs & 

k(298) A Ea B Notes [c]

CP15 RAOOH + CL = #.404 HCL + #.139 OH + 

#.148 HO2 + #.589 RO2C + #.124 RO2XC + 

#.124 zRNO3 + #.074 PROD2 + #.147 MGLY 

+ #.139 IPRD + #.565 xHO2 + #.024 xOH + 

#.448 xRCHO + #.026 xGLY + #.030 xMEK + 

#.252 xMGLY + #.073 xAFG1 + #.073 xAFG2 

+ #.713 yR6OOH + #2.674 XC

4.29e-10 13

CP16 MACR + CL = #.25 HCL + #.165 MACO3 + 

#.802 RO2C + #.033 RO2XC + #.033 zRNO3 

+ #.802 xHO2 + #.541 xCO + #.082 xIPRD + 

#.18 xCLCCHO + #.541 xCLACET + #.835 

yROOH + #.208 XC

3.85e-10 8

CP17 MVK + CL = #1.283 RO2C + #.053 {RO2XC 

+ zRNO3} + #.322 xHO2 + #.625 xMECO3 + 

#.947 xCLCCHO + yROOH + #.538 XC

2.32e-10 8

CP18 IPRD + CL = #.401 HCL + #.084 HO2 + #.154 

MACO3 + #.73 RO2C + #.051 RO2XC + 

#.051 zRNO3 + #.042 AFG1 + #.042 AFG2 + 

#.712 xHO2 + #.498 xCO + #.195 xHCHO + 

#.017 xMGLY + #.009 xAFG1 + #.009 xAFG2 

+ #.115 xIPRD + #.14 xCLCCHO + #.42 

xCLACET + #.762 yR6OOH + #.709 XC

4.12e-10 8,14

Reactions of Chlorinated Organic Product Species

CP19 CLCCHO + HV = HO2 + CO + RO2C + xCL 

+ xHCHO + yROOH

Phot Set= CLCCHO 15

CP20 CLCCHO + OH = RCO3 + #-1 XC 3.10e-12 16

CP21 CLCCHO + CL = HCL + RCO3 + #-1 XC 1.29e-11 16

CP22 CLACET + HV = MECO3 + RO2C + xCL + 

xHCHO + yROOH

Phot Set= CLACET, qy= 0.50 17

Steady-State Peroxy Radical operators (for formation of chlorine radical and product species)

CP23 xCL = CL k is variable parameter: RO2RO 18

CP24 xCL = k is variable parameter: RO2XRO 18

CP25 xCLCCHO = CLCCHO k is variable parameter: RO2RO 18

CP26 xCLCCHO = #2 XC k is variable parameter: RO2XRO 18

CP27 xCLACET = CLACET k is variable parameter: RO2RO 18

CP28 xCLACET = #3 XC k is variable parameter: RO2XRO 18

Chlorine Reactions with Explicitly Represented Primary Organics

CE01 CH4 + CL = HCL + MEO2 1.02e-13 7.30e-12 2.54 1

CE02 ETHENE + CL = #2 RO2C + xHO2 + xHCHO 

+ CLCHO

1.04e-10 Falloff, F=0.60, N=1.00 2
Table A-5 (continued)

166

Label Reaction and Products [a] Rate Parameters [b] Refs & 

k(298) A Ea B Notes [c]

CE03 ISOPRENE + CL = #.15 HCL + #1.168 RO2C 

+ #.085 RO2XC + #.085 zRNO3 + #.738 

xHO2 + #.177 xCL + #.275 xHCHO + #.177 

xMVK + #.671 xIPRD + #.067 xCLCCHO + 

yR6OOH + #.018 XC

4.80e-10 19

CE04 ACETYLEN + CL = HO2 + CO + XC 4.97e-11 Falloff, F=0.60, N=1.00 2,20

0: 5.20e-30 0.00 -2.40

inf: 2.20e-10 0.00 0.00

[a] Format of reaction listing: "=" separates reactants from products; "#number" indicates stoichiometric 

coefficient, "#coefficient {product lis }" means that the stoichiometric coefficient is applied to all the 

products listed.

[b] Except as indicated, the rate constants are given by k(T) = A · (T/300)B· e-Ea/RT, where the units of k 

and A are cm3 molec-1s

-1

, Ea are kcal mol-1, T is oK, and R=0.0019872 kcal mol-1deg-1. The 

following special rate constant expressions are used:

Phot Set = name: The absorption cross sections and (if applicable) quantum yields for the photolysis 

reaction are given in Table A-6, where "name" indicates the photolysis set used. If a "qy=number" 

notation is given, the number given is the overall quantum yield, which is assumed to be 

wavelength independent.

Falloff: The rate constant as a function of temperature and pressure is calculated using k(T,M) = 

{k0(T)·[M]/[1 + k0(T)·[M]/kinf(T)]}· FZ, where Z = {1 + [log10{k0(T)·[M])/kinf(T)}/N]2}

-1

, [M] 

is the total pressure in molecules cm-3, F and N are as indicated on the table, and the temperature 

dependences of k0 and kinf are as indicated on the table.

Same K as Rxn xx: Uses the same rate constant as the reaction in the base mechanism with the same 

label (see Table A-2)

[c] Footnotes documenting sources of rate constants and mechanisms are as follows.

1 Rate constant or absorption coefficients and quantum yields based on IUPAC (2006) 

recommendation. Mechanism is also as recommended unless indicated by other footnotes.

2 Rate constant or absorption coefficients and quantum yields based on NASA (2006) 

recommendation. Mechanism is also as recommended unless indicated by other footnotes.

3 Reaction is rapidly reversed and can be ignored.

4 IUPAC (2006) gives a recommendation for the total CL + HO2 rate constant and for the 

temperature dependence of the rate constant ratio. Temperature-dependent parameters derived to 

give best fits to the recommended temperature dependence expression for the temperature range 

270-330oK.

5 No information could be found concerning the kinetics of this reaction. The temperature- and 

pressure-dependence expression for the rate constant was estimated from that for the reverse 

reaction and the equilibrium constant obtained from the thermochemical data given by NASA 

(2006) for 298oK. The falloff parameters were derived by fitting the falloff expression to the rate 

constant derived from the rate constant calculated for the reverse reaction and the equilibrium 

constant as a function of temperature and pressure.
Table A-5 (continued)

167

6 This reaction is not important under most atmospheric conditions, but may be non-negligible 

under certain situations near Cl2 emissions sources. The reaction can form either Cl2 + O2, Cl + 

ClOO, or Cl + OClO. To avoid introducing new species into the mechanism for this relatively 

unimportant reaction, OClO is represented by Cl. ClOO is also represented by Cl because it is 

expected to rapidly decompose to Cl. The rate expression for the total reaction is derived by 

fitting an Arrhenius expression to the sum of the temperature-dependent rate constants 

recommended by IUPAC (2006). The relative product yields are the IUPAC (2006) 

recommended values for 298K; the temperature dependence of the relative product yields is 

ignored.

7 The rate constant used for the reaction of Cl with propionaldehyde is the average of values listed 

by Le Crane et al (2005), who also obtained data indicating that abstraction from -CHO occurs 

~88% of the time. The rest of the reaction is assumed to occur at the CH2 group, resulting in 

ultimate formation of the corresponding alkoxy radical, which is estimated to decompose 

primarily to acetaldehyde and HCO (Carter, 2000a).

8 Mechanism estimated using the current mechanism generation system, with rates of initial 

reactions determined by estimated rates of Cl reactions at various positions. In most cases the 

reactions of the radicals formed are the same as derived for the SAPRC-99 mechanism 

generation system documented by Carter (2000a). The total rate constant also estimated, unless 

another footnote indicates otherwise.

9 Mechanism derived using the mechanism generation system based on the mixture of organic 

nitrate or higher ketone product compounds used to derive the other mechanistic parameters for 

the RNO3 or PROD2 model species.

10 Same rate constant as used for formaldehyde (for glyoxal) or acetaldehyde (for methyl glyoxal). 

Same mechanism as for OH reaction, except HCl formed.

11 Assumed to have same rate constant as used for toluene, which is average of values tabulated by 

Wang et al (2005). Mechanism based on assuming reaction only involves abstraction from CH3.

12 Same rate constant as used for acetaldehyde. Reaction is assumed to proceed only by abstraction 

from -CHO.

13 Mechanism could not be generated completely. The mechanism estimation system was used to 

estimate the total rate constant and the HCL yield. The set of products formed in the OH reaction 

are used to approximate the reminder of the products radicals formed.

14 Mechanism derived for HCOC(CH3)=CHCH2OH, which is taken as representative of the 

compounds represented by this model species. 0.5 AFG1 + 0.5 AFG2 are used to represent the 

CH3-C(CHO)=CH-CHO product predicted to be formed.

15 This is used to represent alpha-chloro aldehydes, which need to be represented separately 

because of their significantly higher photolysis rates (see Carter and Malkina, 2007). Absorption 

cross-sections from NASA (2006), and are given in Table 5. Unit quantum yields assumed. See 

Carter and Malkina (2007) for a discussion of the mechanism.

16 Rate constants from Scollard et al (1993). Represented as forming same products as 

corresponding reaction of propionaldehyde.

17 Absorption cross-sections from NASA (2006) evaluation. Overall quantum yield of 0.5 assumed, 

based on quantum yields measured at 308 and 351 nm (NASA, 2006).

18 See footnotes in Table A-2 for a discussion of these xPROD operators.
Table A-5 (continued)

168

19 Rate constant is Atkinson (1997) recommendation. Mechanism derived using the mechanism 

generation system, with assignments for the formation and reactions of the initially formed 

radicals based on the mechanism of Fan and Zhang (2004). Note that if it is desired to represent 

CMBO and CMBA explicitly, the "IPRD" yield should be reduced to 0.272 and the CMBO and 

CMBA should be added with yields of 0.221 and 0.178, respectively. Their subsequent reactions 

can be approximated by the mechanism of IPRD.

20 Mechanism based on assuming that reaction involves formation of ClCH=CH· radicals, which 

react with O2 to form HCO and ClCHO. The latter is assumed to be relatively unreactive and is 

not represented.
169

Table A-6. Absorption cross-sections and quantum yields for the all photolysis reactions added for 

the chlorine chemistry mechanism.

a) Phot set CL2: Chlorine absorption cross-sections.

wl abs wl abs wl abs wl abs wl abs wl abs

280 2.60e-20 320 2.37e-19 360 1.32e-19 400 1.80e-20 440 5.40e-21 480 -

290 6.20e-20 330 2.55e-19 370 8.40e-20 410 1.30e-20 450 3.80e-21

300 1.19e-19 340 2.35e-19 380 5.00e-20 420 9.60e-21 460 2.60e-21

310 1.85e-19 350 1.88e-19 390 2.90e-20 430 7.30e-21 470 1.60e-21

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation for absorptioncross sections. Unit quantum yield assumed.

b) Phot Set CLNO-06: ClNO absorption cross-sections.

wl abs wl abs wl abs wl abs wl abs wl abs

280 1.06e-19 304 1.05e-19 328 1.46e-19 355 1.36e-19 415 3.38e-20 475 2.61e-20

282 1.02e-19 306 1.08e-19 330 1.47e-19 360 1.29e-19 420 2.89e-20 480 2.53e-20

284 9.99e-20 308 1.11e-19 332 1.49e-19 365 1.20e-19 425 2.45e-20 485 2.33e-20

286 9.84e-20 310 1.15e-19 334 1.51e-19 370 1.10e-19 430 2.21e-20 490 2.07e-20

288 9.71e-20 312 1.19e-19 336 1.53e-19 375 9.95e-20 435 2.20e-20 495 1.78e-20

290 9.64e-20 314 1.22e-19 338 1.53e-19 380 8.86e-20 440 2.20e-20 500 1.50e-20

292 9.63e-20 316 1.25e-19 340 1.52e-19 385 7.82e-20 445 2.07e-20 527 -

294 9.69e-20 318 1.30e-19 342 1.53e-19 390 6.86e-20 450 1.87e-20

296 9.71e-20 320 1.34e-19 344 1.51e-19 395 5.97e-20 455 1.79e-20

298 9.89e-20 322 1.36e-19 346 1.51e-19 400 5.13e-20 460 1.95e-20

300 1.00e-19 324 1.40e-19 348 1.49e-19 405 4.40e-20 465 2.25e-20

302 1.03e-19 326 1.43e-19 350 1.45e-19 410 3.83e-20 470 2.50e-20

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation. Unit quantum 

yields assumed. Wavelength where absorption goes to zero estimated by extrapolation.

c) Phot set CLONO: ClONO absorption cross-sections.

wl abs wl abs wl abs wl abs wl abs wl abs

280 1.32e-18 305 1.14e-18 330 5.87e-19 355 2.29e-19 380 4.10e-20 405 -

285 1.44e-18 310 1.05e-18 335 5.77e-19 360 1.61e-19 385 3.30e-20

290 1.44e-18 315 9.81e-19 340 4.37e-19 365 1.13e-19 390 2.20e-20

295 1.42e-18 320 8.03e-19 345 3.57e-19 370 9.00e-20 395 1.50e-20

300 1.29e-18 325 7.54e-19 350 2.69e-19 375 6.90e-20 400 6.00e-21

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation for absorption 

cross-sections. Unit quantum yield assumed.
Table A-6 (continued)

170

d) Phot set CLNO2: ClNO2 absorption cross-sections

wl abs wl abs wl abs wl abs

280 2.20e-19 310 1.21e-19 340 3.54e-20 370 6.90e-21

290 1.73e-19 320 8.87e-20 350 2.04e-20 380 -

300 1.49e-19 330 5.84e-20 360 1.15e-20

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation. Unit quantum 

yields assumed.

e) Phot Set CLONO2-1: ClONO2 + hv = CLO + NO2

wl abs qy wl abs qy wl abs qy wl abs qy

280 1.19e-19 0.400 305 2.24e-20 0.400 330 4.66e-21 0.243 355 2.08e-21 0.064

285 8.80e-20 0.400 310 1.60e-20 0.386 335 3.67e-21 0.207 360 2.00e-21 0.029

290 6.41e-20 0.400 315 1.14e-20 0.350 340 3.02e-21 0.171 365 1.80e-21 0.000

295 4.38e-20 0.400 320 8.31e-21 0.314 345 2.58e-21 0.136

300 3.13e-20 0.400 325 6.13e-21 0.279 350 2.29e-21 0.100

Wavelengths in nm and absorption cross-sections in cm-2. Absorption cross-sections and quantum yields 

recommended by IUPAC (2006).

f) Phot Set CLONO2-2: ClONO2 + hv = Cl + NO3

wl abs qy wl abs qy wl abs qy wl abs qy

280 1.19e-19 0.600 320 8.31e-21 0.686 360 2.00e-21 0.971 400 6.40e-22 1.000

285 8.80e-20 0.600 325 6.13e-21 0.721 365 1.80e-21 1.000 405 5.40e-22 1.000

290 6.41e-20 0.600 330 4.66e-21 0.757 370 1.59e-21 1.000 410 4.40e-22 1.000

295 4.38e-20 0.600 335 3.67e-21 0.793 375 1.41e-21 1.000 415 3.60e-22 1.000

300 3.13e-20 0.600 340 3.02e-21 0.829 380 1.21e-21 1.000 420 3.20e-22 1.000

305 2.24e-20 0.600 345 2.58e-21 0.864 385 1.37e-21 1.000 425 2.30e-22 1.000

310 1.60e-20 0.614 350 2.29e-21 0.900 390 9.10e-22 1.000 430 1.90e-22 1.000

315 1.14e-20 0.650 355 2.08e-21 0.936 395 7.60e-22 1.000 435 - 1.000

Wavelengths in nm and absorption cross-sections in cm-2. Absorption cross-sections and quantum yields 

recommended by IUPAC (2006).

g) Phot set HOCL-06: HOCl absorption cross-sections.

wl abs wl abs wl abs wl abs wl abs wl abs

280 4.64e-20 304 6.12e-20 328 3.79e-20 352 1.33e-20 376 7.86e-21 400 2.88e-21

282 4.62e-20 306 6.12e-20 330 3.50e-20 354 1.24e-20 378 7.48e-21 402 2.54e-21

284 4.68e-20 308 6.07e-20 332 3.21e-20 356 1.17e-20 380 7.08e-21 404 2.22e-21

286 4.79e-20 310 5.97e-20 334 2.94e-20 358 1.11e-20 382 6.67e-21 406 1.94e-21

288 4.95e-20 312 5.84e-20 336 2.68e-20 360 1.06e-20 384 6.24e-21 408 1.68e-21

290 5.13e-20 314 5.66e-20 338 2.44e-20 362 1.02e-20 386 5.80e-21 410 1.44e-21

292 5.33e-20 316 5.45e-20 340 2.22e-20 364 9.85e-21 388 5.35e-21 412 1.24e-21

294 5.52e-20 318 5.21e-20 342 2.03e-20 366 9.51e-21 390 4.91e-21 414 1.05e-21

296 5.71e-20 320 4.95e-20 344 1.84e-20 368 9.19e-21 392 4.47e-21 416 8.90e-22

298 5.86e-20 322 4.67e-20 346 1.69e-20 370 8.88e-21 394 4.05e-21 418 7.50e-22

300 5.99e-20 324 4.38e-20 348 1.55e-20 372 8.55e-21 396 3.64e-21 420 6.30e-22
Table A-6 (continued)

171

302 6.08e-20 326 4.09e-20 350 1.43e-20 374 8.22e-21 398 3.25e-21 422 -

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation for absorption 

cross-sections. Unit quantum yields assumed.

h) Phot set CLCCHO: Chloroacetaldehyde absorption cross-sections.

wl abs wl abs wl abs wl abs wl abs wl abs

280 3.99e-20 293 5.14e-20 306 5.48e-20 319 3.78e-20 332 1.68e-20 345 1.59e-21

281 4.23e-20 294 5.48e-20 307 5.34e-20 320 3.84e-20 333 1.42e-20 346 1.36e-21

282 4.09e-20 295 5.47e-20 308 5.44e-20 321 3.43e-20 334 1.36e-20 347 9.77e-22

283 4.15e-20 296 5.64e-20 309 5.37e-20 322 3.26e-20 335 1.06e-20 348 7.91e-22

284 4.31e-20 297 5.56e-20 310 5.03e-20 323 2.49e-20 336 7.47e-21 349 6.23e-22

285 4.55e-20 298 5.75e-20 311 4.61e-20 324 2.11e-20 337 6.22e-21 350 5.45e-22

286 4.64e-20 299 5.63e-20 312 3.92e-20 325 1.92e-20 338 5.02e-21 351 5.58e-22

287 4.80e-20 300 5.57e-20 313 3.71e-20 326 1.87e-20 339 4.11e-21 352 6.03e-22

288 4.99e-20 301 5.10e-20 314 3.73e-20 327 1.87e-20 340 3.40e-21 353 6.33e-22

289 5.03e-20 302 4.92e-20 315 3.96e-20 328 1.70e-20 341 2.81e-21 354 5.65e-22

290 5.20e-20 303 5.01e-20 316 3.85e-20 329 1.92e-20 342 2.47e-21 355 3.77e-22

291 4.95e-20 304 5.30e-20 317 4.16e-20 330 1.64e-20 343 2.13e-21 356 2.39e-22

292 4.94e-20 305 5.27e-20 318 3.84e-20 331 1.52e-20 344 1.90e-21 357 1.23e-22

358 -

Wavelengths in nm and absorption cross-sections in cm-2. Absorption cross-sections from NASA (2006) 

evaluation. Unit quantum yields assumed.

g) Phot set CLACET: Chloroacetone absorption cross-sections.

wl abs wl abs wl abs wl abs wl abs wl abs

280 9.03e-20 294 1.01e-19 308 7.34e-20 322 3.04e-20 336 5.06e-21 350 4.58e-22

281 9.23e-20 295 1.00e-19 309 7.06e-20 323 2.80e-20 337 4.27e-21 351 4.11e-22

282 9.41e-20 296 9.89e-20 310 6.77e-20 324 2.58e-20 338 3.61e-21 352 3.28e-22

283 9.56e-20 297 9.77e-20 311 6.50e-20 325 2.37e-20 339 3.02e-21 353 3.19e-22

284 9.69e-20 298 9.66e-20 312 6.22e-20 326 2.16e-20 340 2.52e-21 354 2.20e-22

285 9.80e-20 299 9.54e-20 313 5.93e-20 327 1.95e-20 341 2.12e-21 355 1.93e-22

286 9.89e-20 300 9.41e-20 314 5.61e-20 328 1.73e-20 342 1.76e-21 356 1.38e-22

287 9.98e-20 301 9.25e-20 315 5.28e-20 329 1.52e-20 343 1.45e-21 357 1.34e-22

288 1.00e-19 302 9.04e-20 316 4.92e-20 330 1.33e-20 344 1.20e-21 358 9.17e-23

289 1.01e-19 303 8.80e-20 317 4.57e-20 331 1.14e-20 345 1.03e-21 359 1.55e-22

290 1.02e-19 304 8.53e-20 318 4.22e-20 332 9.79e-21 346 8.87e-22 360 1.28e-22

291 1.02e-19 305 8.24e-20 319 3.89e-20 333 8.32e-21 347 7.57e-22 365 -

292 1.02e-19 306 7.94e-20 320 3.58e-20 334 7.07e-21 348 6.42e-22

293 1.02e-19 307 7.63e-20 321 3.30e-20 335 5.98e-21 349 5.47e-22

Wavelengths in nm and absorption cross-sections in cm-2. NASA (2006) recommendation for absorption 

cross-sections. Unit quantum yields assumed.
172

Table A-7. Listing of reactions and rate parameters used for the lumped model species in the fixed 

parameter version of the lumped SAPRC-07 mechanism.

Label Reaction and Products [a] Rate Parameters [b]

k(300) A Ea B

Reactions Added to the Standard Base Mechanism

BL01 ALK1 + OH = xHO2 + RO2C + xCCHO + yROOH 2.54E-13 1.34E-12 0.992 2.0

BL02 ALK2 + OH = #.965 xHO2 + #.965 RO2C + #.035 

RO2XC + #.035 zRNO3 + #.261 xRCHO + #.704 

xACET + yROOH + #-.105 XC

1.11E-12 1.49E-12 0.173 2.0

BL03 ALK3 + OH = #.695 xHO2 + #.236 xTBUO + #1.253 

RO2C + #.07 RO2XC + #.07 zRNO3 + #.026 

xHCHO + #.445 xCCHO + #.122 xRCHO + #.024 

xACET + #.332 xMEK + #.983 yROOH + #.017 

yR6OOH + #-.046 XC

2.31E-12 1.51E-12 -0.251

BL04 ALK4 + OH = #.83 xHO2 + #.01 xMEO2 + #.011 

xMECO3 + #1.763 RO2C + #.149 RO2XC + #.149 

zRNO3 + #.002 xCO + #.029 xHCHO + #.438 

xCCHO + #.236 xRCHO + #.426 xACET + #.106 

xMEK + #.146 xPROD2 + yR6OOH + #-.119 XC

4.34E-12 3.75E-12 -0.088

BL05 ALK5 + OH = #.647 xHO2 + #1.605 RO2C + #.353 

RO2XC + #.353 zRNO3 + #.04 xHCHO + #.106 

xCCHO + #.209 xRCHO + #.071 xACET + #.086 

xMEK + #.407 xPROD2 + yR6OOH + #2.004 XC

9.40E-12 2.70E-12 -0.744

BL06 OLE1 + OH = #.904 xHO2 + #.001 xMEO2 + #1.138 

RO2C + #.095 RO2XC + #.095 zRNO3 + #.7 

xHCHO + #.301 xCCHO + #.47 xRCHO + #.005 

xACET + #.026 xMACR + #.008 xMVK + #.006 

xIPRD + #.119 xPROD2 + #.413 yROOH + #.587 

yR6OOH + #.822 XC

3.29E-11 6.18E-12 -0.996

BL07 OLE1 + O3 = #.116 HO2 + #.04 xHO2 + #.193 OH + 

#.104 MEO2 + #.063 RO2C + #.004 RO2XC + #.004 

zRNO3 + #.368 CO + #.125 CO2 + #.5 HCHO + 

#.147 CCHO + #.007 xCCHO + #.353 RCHO + #.031 

xRCHO + #.002 xACET + #.006 MEK + #.185 

HCOOH + #.022 CCOOH + #.112 RCOOH + #.189 

PROD2 + #.007 yROOH + #.037 yR6OOH + #.69 

XC

1.09E-17 3.15E-15 3.379

BL08 OLE1 + NO3 = #.824 xHO2 + #1.312 RO2C + #.176 

RO2XC + #.176 zRNO3 + #.009 xCCHO + #.002 

xRCHO + #.024 xACET + #.546 xRNO3 + #.413 

yROOH + #.587 yR6OOH + #.454 XN + #.572 XC

1.44E-14 4.73E-13 2.081

BL09 OLE1 + O3P = #.45 RCHO + #.437 MEK + #.113 

PROD2 + #1.224 XC

5.02E-12 1.49E-11 0.648
Table A-7 (continued)

173

Label Reaction and Products [a] Rate Parameters [b]

k(300) A Ea B

BL10 OLE2 + OH = #.914 xHO2 + #.966 RO2C + #.086 

RO2XC + #.086 zRNO3 + #.209 xHCHO + #.788 

xCCHO + #.481 xRCHO + #.136 xACET + #.076 

xMEK + #.027 xMACR + #.002 xMVK + #.037 

xIPRD + #.022 xPROD2 + #.357 yROOH + #.643 

yR6OOH + #.111 XC

6.42E-11 1.26E-11 -0.969

BL11 OLE2 + O3 = #.093 HO2 + #.039 xHO2 + #.423 OH 

+ #.29 MEO2 + #.147 xMECO3 + #.008 xRCO3 + 

#.2 RO2C + #.003 RO2XC + #.003 zRNO3 + #.297 

CO + #.162 CO2 + #.152 HCHO + #.108 xHCHO + 

#.428 CCHO + #.067 xCCHO + #.315 RCHO + #.018 

xRCHO + #.048 ACET + #.031 MEK + #.001 xMEK 

+ #.033 HCOOH + #.061 CCOOH + #.222 RCOOH 

+ #.028 MACR + #.021 MVK + #.042 PROD2 + 

#.069 yROOH + #.128 yR6OOH + #.125 XC

1.24E-16 8.14E-15 2.494

BL12 OLE2 + NO3 = #.423 xHO2 + #.409 xNO2 + #.033 

xMEO2 + #1.185 RO2C + #.136 RO2XC + #.136 

zRNO3 + #.074 xHCHO + #.546 xCCHO + #.154 

xRCHO + #.11 xACET + #.002 xMEK + #.026 

xMVK + #.007 xIPRD + #.322 xRNO3 + #.357 

yROOH + #.643 yR6OOH + #.269 XN + #.114 XC

7.85E-13 2.20E-13 -0.759

BL13 OLE2 + O3P = #.014 HO2 + #.007 xHO2 + #.007 

xMACO3 + #.013 RO2C + #.001 RO2XC + #.001 

zRNO3 + #.006 xCO + #.074 RCHO + #.709 MEK + 

#.006 xMACR + #.202 PROD2 + #.014 yROOH + 

#.666 XC

2.07E-11 1.43E-11 -0.220

BL14 ARO1 + OH = #.166 HO2 + #.482 xHO2 + #.284 OH 

+ #.482 RO2C + #.068 RO2XC + #.068 zRNO3 + 

#.218 xGLY + #.138 xMGLY + #.166 CRES + #.049 

xBALD + #.164 xAFG1 + #.193 xAFG2 + #.284 

AFG3 + #.077 xPROD2 + #.403 yRAOOH + #.147 

yR6OOH + #.002 XC

6.15E-12

BL15 ARO2 + OH = #.108 HO2 + #.58 xHO2 + #.202 OH 

+ #.58 RO2C + #.11 RO2XC + #.11 zRNO3 + #.116 

xGLY + #.286 xMGLY + #.104 xBACL + #.108 

CRES + #.039 xBALD + #.217 xAFG1 + #.21 

xAFG2 + #.202 AFG3 + #.08 xAFG3 + #.035 

xPROD2 + #.089 yR6OOH + #.601 yRAOOH + 

#1.486 XC

2.57E-11
Table A-7 (continued)

174

Label Reaction and Products [a] Rate Parameters [b]

k(300) A Ea B

BL16 TERP + OH = #.759 xHO2 + #.042 xRCO3 + #1.147 

RO2C + #.2 RO2XC + #.2 zRNO3 + #.001 xCO + 

#.264 xHCHO + #.533 xRCHO + #.036 xACET + 

#.005 xMEK + #.009 xMGLY + #.014 xBACL + 

#.002 xMVK + #.001 xIPRD + #.255 xPROD2 + 

yR6OOH + #5.056 XC

7.98E-11 1.87E-11 -0.864

BL17 TERP + O3 = #.052 HO2 + #.067 xHO2 + #.585 OH 

+ #.126 xMECO3 + #.149 xRCO3 + #.875 RO2C + 

#.203 RO2XC + #.203 zRNO3 + #.166 CO + #.019 

xCO + #.045 CO2 + #.079 HCHO + #.15 xHCHO + 

#.22 xRCHO + #.165 xACET + #.004 MEK + #.107 

HCOOH + #.043 RCOOH + #.001 xGLY + #.002 

xMGLY + #.055 xBACL + #.001 xMACR + #.001 

xIPRD + #.409 PROD2 + #.545 yR6OOH + #3.526 

XC

6.99E-17 9.57E-16 1.560

BL18 TERP + NO3 = #.162 xHO2 + #.421 xNO2 + #.019 

xRCO3 + #1.509 RO2C + #.397 RO2XC + #.397 

zRNO3 + #.01 xCO + #.017 xHCHO + #.001 xCCHO

+ #.509 xRCHO + #.175 xACET + #.001 xMGLY + 

#.003 xMACR + #.001 xMVK + #.002 xIPRD + 

#.163 xRNO3 + yR6OOH + #.416 XN + #4.473 XC

6.53E-12 1.28E-12 -0.974

BL19 TERP + O3P = #.147 RCHO + #.853 PROD2 + 

#4.441 XC

3.71E-11

Reactions Added to the Base Mechanism with Chlorine Chemistry

BC01 ALK1 + CL = xHO2 + RO2C + HCL + xCCHO + 

yROOH

5.95E-11 8.30E-11 0.199

BC02 ALK2 + CL = #.97 xHO2 + #.97 RO2C + #.03 

RO2XC + #.03 zRNO3 + HCL + #.482 xRCHO + 

#.488 xACET + yROOH + #-.09 XC

1.37E-10 1.20E-10 -0.079

BC03 ALK3 + CL = #.835 xHO2 + #.094 xTBUO + #1.361 

RO2C + #.07 RO2XC + #.07 zRNO3 + HCL + #.078 

xHCHO + #.34 xCCHO + #.343 xRCHO + #.075 

xACET + #.253 xMEK + #.983 yROOH + #.017 

yR6OOH + #.18 XC

1.86E-10

BC04 ALK4 + CL = #.827 xHO2 + #.003 xMEO2 + #.004 

xMECO3 + #1.737 RO2C + #.165 RO2XC + #.165 

zRNO3 + HCL + #.003 xCO + #.034 xHCHO + #.287 

xCCHO + #.412 xRCHO + #.247 xACET + #.076 

xMEK + #.13 xPROD2 + yR6OOH + #.327 XC

2.63E-10
Table A-7 (continued)

175

Label Reaction and Products [a] Rate Parameters [b]

k(300) A Ea B

BC05 ALK5 + CL = #.647 xHO2 + #1.541 RO2C + #.352 

RO2XC + #.352 zRNO3 + HCL + #.022 xHCHO + 

#.08 xCCHO + #.258 xRCHO + #.044 xACET + 

#.041 xMEK + #.378 xPROD2 + yR6OOH + #2.368 

XC

4.21E-10

BC06 OLE1 + CL = #.902 xHO2 + #1.42 RO2C + #.098 

RO2XC + #.098 zRNO3 + #.308 HCL + #.025 

xHCHO + #.146 xCCHO + #.051 xRCHO + #.188 

xMACR + #.014 xMVK + #.027 xIPRD + #.225 

xCLCCHO + #.396 xCLACET + #.413 yROOH + 

#.587 yR6OOH + #1.361 XC

3.55E-10

BC07 OLE2 + CL = #.447 xHO2 + #.448 xCL + #.001 

xMEO2 + #1.514 RO2C + #.104 RO2XC + #.104 

zRNO3 + #.263 HCL + #.228 xHCHO + #.361 

xCCHO + #.3 xRCHO + #.081 xACET + #.04 xMEK 

+ #.049 xMACR + #.055 xMVK + #.179 xIPRD + 

#.012 xCLCCHO + #.18 xCLACET + #.357 yROOH 

+ #.643 yR6OOH + #.247 XC

3.83E-10

BC08 ARO1 + CL = #.88 xHO2 + #.88 RO2C + #.12 

RO2XC + #.12 zRNO3 + #.671 xBALD + #.21 

xPROD2 + #.323 XC

1.00E-10

BC09 ARO2 + CL = #.842 xHO2 + #.842 RO2C + #.158 

RO2XC + #.158 zRNO3 + #.618 xBALD + #.224 

xPROD2 + #2.382 XC

2.18E-10

BC10 TERP + CL = #.252 xHO2 + #.068 xCL + #.034 

xMECO3 + #.05 xRCO3 + #.016 xMACO3 + #2.258 

RO2C + #.582 RO2XC + #.582 zRNO3 + #.548 HCL 

+ #.035 xCO + #.158 xHCHO + #.185 xRCHO + 

#.274 xACET + #.007 xGLY + #.003 xBACL + #.003 

xMVK + #.158 xIPRD + #.006 xAFG1 + #.006 

xAFG2 + #.001 xAFG3 + #.109 xCLCCHO + 

yR6OOH + #3.543 XC

5.46E-10

[a] Format of reaction listing: "=" separates reactants from products; "#number" indicates stoichiometric 

coefficient, "#coefficient {product list}" means that the stoichiometric coefficient is applied to all the 

products listed.

[b] The rate constants are given by k(T) = A · e-Ea/RT, where the units of k and A are cm3 molec-1s

-1

, Ea 

are kcal mol-1, T is oK, and R=0.0019872 kcal mol-1deg-1.
176

APPENDIX B. MECHANISM AND REACTIVITY LISTINGS FOR INDIVIDUAL VOCS

This Appendix contains the tables documenting the mechanisms and giving the calculated 

atmospheric reactivity values and associated codes for the individual VOCs for which mechanistic 

assignments have been made. These tables are also available in electronic form in an Excel file, as 

discussed in Appendix D. Because of their size, Table B-2 , Table B-3, Table B-10, and Table B-11 are 

only available in this electronic format.
177

Table B-1. Listing of detailed model species, their representation in the model, and calculated 

atmospheric reactivity values in various reactivity scales 

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

Alkanes

methane 74-82-8 16.04 Exp 1 0 6 .0144 .0085 .0060 .0073±.0016

ethane 74-84-0 30.07 Exp 1 3 0 1 0.28 0.196 0.142 0.167±0.045

propane 74-98-6 44.10 Exp 1 3 0 1 0.49 0.34 0.25 0.29±0.07

cyclopropane 75-19-4 42.08 Exp 1 0 6 0.087 0.061 0.043 0.051±0.015

n-butane 106-97-8 58.12 Exp 1 2 0 1 1.15 0.76 0.52 0.64±0.17

isobutane 75-28-5 58.12 Exp 1 3 0 2 1.23 0.73 0.50 0.62±0.14

cyclobutane 287-23-0 56.11 Exp 1 0 6 1.20 0.80 0.54 0.66±0.22

n-pentane 109-66-0 72.15 Exp 1 0 6 1.31 0.88 0.56 0.70±0.21

branched C5 alkanes 72.15 LM 0 8 1.45 0.93 0.65 0.79±0.20

neopentane 463-82-1 72.15 Exp 1 0 6 0.67 0.39 0.26 0.33±0.08

isopentane 78-78-4 72.15 Exp 1 0 6 1.45 0.93 0.65 0.79±0.20

cyclopentane 287-92-3 70.13 AdjP 1 0 6 2.39 1.41 0.89 1.15±0.35

n-hexane 110-54-3 86.18 Exp 1 3 0 2 1.24 0.84 0.50 0.65±0.22

branched C6 alkanes 86.18 LM 0 8 1.31 0.83 0.55 0.68±0.18

2,2-dimethyl butane 75-83-2 86.18 Exp 1 0 6 1.17 0.71 0.46 0.58±0.16

2,3-dimethyl butane 79-29-8 86.18 Exp 1 0 6 0.97 0.65 0.44 0.54±0.13

2-methyl pentane 107-83-5 86.18 Exp 1 0 6 1.50 0.92 0.57 0.74±0.23

3-methyl pentane 96-14-0 86.18 Exp 1 0 6 1.80 1.11 0.73 0.92±0.26

C6 cycloalkanes 84.16 LM 0 8 1.25 0.82 0.47 0.63±0.22

cyclohexane 110-82-7 84.16 AdjP 1 2 0 2 1.25 0.82 0.47 0.63±0.22

isopropyl cyclopropane 3638-35-5 84.16 Exp 1 0 6 1.22 0.80 0.54 0.66±0.18

methyl cyclopentane 96-37-7 84.16 AdjP 0 7 2.19 1.23 0.73 0.98±0.33

Unspeciated C6 Alkanes 85.51 Mix 0 8 1.27 0.83 0.50 0.65±0.21

n-heptane 142-82-5 100.20 Exp 1 0 6 1.07 0.73 0.39 0.54±0.21

2,2,3-trimethyl butane 464-06-2 100.20 Exp 1 0 6 1.11 0.66 0.42 0.54±0.14

2,2-dimethyl pentane 590-35-2 100.20 Exp 1 0 6 1.12 0.68 0.41 0.54±0.17

2,3-dimethyl pentane 565-59-3 100.20 Exp 0 7 1.34 0.83 0.52 0.67±0.19

2,4-dimethyl pentane 108-08-7 100.20 Exp 1 0 6 1.55 0.90 0.55 0.72±0.22

2-methyl hexane 591-76-4 100.20 AdjP 0 7 1.19 0.76 0.42 0.58±0.21

3,3-dimethyl pentane 562-49-2 100.20 Exp 0 7 1.20 0.76 0.49 0.62±0.18

3-methyl hexane 589-34-4 100.20 Exp 0 7 1.61 0.96 0.57 0.76±0.26

3-ethyl pentane 617-78-7 100.20 Exp 0 7 1.90 1.11 0.69 0.90±0.27

branched C7 alkanes 100.20 LM 0 8 1.48 0.88 0.52 0.69±0.22

1,1-dimethyl cyclopentane 1638-26-2 98.19 AdjP 0 7 1.08 0.66 0.35 0.49±0.19

1,2-dimethyl cyclopentane 2452-99-5 98.19 AdjP 0 7 1.99 1.10 0.61 0.85±0.31

C7 cycloalkanes 98.19 LM 0 7 1.70 1.00 0.53 0.75±0.29

1,3-dimethyl cyclopentane 2453-00-1 98.19 AdjP 0 7 1.94 1.06 0.58 0.82±0.30

cycloheptane 291-64-5 98.19 AdjP 1 0 6 1.96 1.11 0.61 0.85±0.32

ethyl cyclopentane 1640-89-7 98.19 AdjP 0 7 2.01 1.13 0.63 0.87±0.33

methyl cyclohexane 108-87-2 98.19 AdjP 1 0 6 1.70 1.00 0.53 0.75±0.29

Unspeciated C7 Alkanes 99.53 Mix 0 8 1.41 0.87 0.48 0.66±0.24

n-octane 111-65-9 114.23 Exp 1 1 0 2 0.90 0.61 0.29 0.43±0.19

branched C8 alkanes 114.23 LM 0 8 1.45 0.86 0.46 0.64±0.24

2,2,3,3-tetramethyl butane 594-82-1 114.23 Exp 1 0 6 0.33 0.20 0.113 0.154±0.052

2,2,4-trimethyl pentane 540-84-1 114.23 Exp 1 3 0 2 1.26 0.71 0.44 0.57±0.17
Table B-1 (continued)

178

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

2,2-dimethyl hexane 590-73-8 114.23 Exp 1 0 6 1.02 0.61 0.33 0.46±0.17

2,3,4-trimethyl pentane 565-75-3 114.23 Exp 1 0 6 1.03 0.65 0.39 0.51±0.16

2,3-dimethyl hexane 584-94-1 114.23 Exp 0 7 1.19 0.75 0.42 0.57±0.20

2,4-dimethyl hexane 589-43-5 114.23 Exp 0 7 1.73 0.98 0.54 0.75±0.27

2,5-dimethyl hexane 592-13-2 114.23 Exp 0 7 1.46 0.86 0.47 0.65±0.24

2-methyl heptane 592-27-8 114.23 Exp 0 7 1.07 0.69 0.35 0.50±0.21

3-methyl heptane 589-81-1 114.23 Exp 0 7 1.24 0.78 0.41 0.58±0.23

4-methyl heptane 589-53-7 114.23 Exp 0 7 1.25 0.76 0.40 0.57±0.23

2,3,3-trimethyl pentane 560-21-4 114.23 Exp 0 7 1.02 0.65 0.41 0.52±0.15

3,3-dimethyl hexane 563-16-6 114.23 Exp 0 7 1.24 0.75 0.43 0.58±0.20

2,2,3-trimethyl pentane 564-02-3 114.23 Exp 0 7 1.22 0.71 0.42 0.56±0.17

3,4-dimethyl hexane 583-48-2 114.23 Exp 0 7 1.51 0.91 0.54 0.71±0.23

3-ethyl 2-methyl pentane 609-26-7 114.23 Exp 0 7 1.33 0.79 0.46 0.62±0.21

C8 bicycloalkanes 110.20 LM 0 8 1.51 0.89 0.48 0.67±0.26

1,1,2-trimethyl cyclopentane 4259-00-1 112.21 Exp 0 7 1.12 0.65 0.33 0.48±0.20

1,1,3-trimethyl cyclopentane 4516-69-2 112.21 Exp 0 7 1.01 0.60 0.29 0.43±0.19

1,1-dimethyl cyclohexane 590-66-9 112.21 Exp 0 7 1.22 0.73 0.37 0.53±0.22

1,2,3-trimethyl cyclopentane 112.21 Exp 0 7 1.63 0.93 0.49 0.70±0.27

1,2,4-trimethyl cyclopentane 112.21 Exp 0 7 1.53 0.85 0.43 0.63±0.26

1-methyl-3-ethyl cyclopentane 112.21 AdjP 0 7 1.64 0.92 0.47 0.68±0.29

1,2-dimethyl cyclohexane 583-57-3 112.21 AdjP 0 7 1.41 0.87 0.43 0.63±0.28

1,4-dimethyl cyclohexane 589-90-2 112.21 AdjP 0 7 1.62 0.91 0.45 0.67±0.29

C8 cycloalkanes 112.21 LM 0 8 1.47 0.87 0.45 0.65±0.26

1,3-dimethyl cyclohexane 591-21-9 112.21 AdjP 0 7 1.52 0.86 0.41 0.62±0.28

cyclooctane 292-64-8 112.21 AdjP 1 0 6 1.46 0.84 0.41 0.61±0.28

ethyl cyclohexane 1678-91-7 112.21 Exp 0 7 1.47 0.87 0.45 0.65±0.26

propyl cyclopentane 2040-96-2 112.21 AdjP 0 7 1.69 0.94 0.48 0.70±0.30

Unspeciated C8 Alkanes 113.56 Mix 0 8 1.27 0.78 0.40 0.57±0.23

n-nonane 111-84-2 128.26 Exp 1 0,+ 6 b 0.78 0.53 0.23 0.36±0.18

branched C9 alkanes 128.26 LM 0 8 b 1.14 0.69 0.33 0.49±0.22

2,2,5-trimethyl hexane 3522-94-9 128.26 Exp 0 7 b 1.13 0.65 0.36 0.50±0.18

2,3,5-trimethyl hexane 1069-53-0 128.26 AdjP 1 0 6 b 1.22 0.73 0.39 0.55±0.20

2,4-dimethyl heptane 2213-23-2 128.26 Exp 0 7 b 1.38 0.79 0.39 0.58±0.25

2-methyl octane 3221-61-2 128.26 Exp 1 0,+ 6 b 0.83 0.55 0.24 0.38±0.19

3,3-diethyl pentane 1067-20-5 128.26 Exp 1 0,+ 6 b 1.21 0.74 0.44 0.58±0.20

3,5-dimethyl heptane 926-82-9 128.26 Exp 0 7 b 1.56 0.92 0.48 0.69±0.28

4-ethyl heptane 2216-32-2 128.26 Exp 0 7 b 1.22 0.74 0.37 0.54±0.23

4-methyl octane 2216-34-4 128.26 Exp 1 0,+ 6 b 0.95 0.62 0.29 0.43±0.20

2,4,4-trimethyl hexane 16747-30-1 128.26 Exp 0 7 b 1.34 0.76 0.42 0.58±0.21

3,3-dimethyl heptane 4032-86-4 128.26 Exp 0 7 b 1.13 0.69 0.37 0.52±0.20

4,4-dimethyl heptane 1068-19-5 128.26 Exp 0 7 b 1.27 0.73 0.39 0.55±0.22

2,2-dimethyl heptane 1071-26-7 128.26 Exp 0 7 b 1.00 0.59 0.30 0.44±0.18

2,2,4-trimethyl hexane 16747-26-5 128.26 Exp 0 7 b 1.26 0.71 0.36 0.53±0.21

2,6-dimethyl heptane 1072-05-5 128.26 Exp 0 7 b 1.04 0.63 0.31 0.46±0.20

2,3-dimethyl heptane 3074-71-3 128.26 Exp 0 7 b 1.09 0.69 0.35 0.50±0.21

2,5-dimethyl heptane 2216-30-0 128.26 Exp 0 7 b 1.35 0.82 0.43 0.61±0.24

3-methyl octane 2216-33-3 128.26 Exp 0 7 b 0.99 0.63 0.30 0.45±0.20

3,4-dimethyl heptane 922-28-1 128.26 Exp 0 7 b 1.24 0.76 0.41 0.57±0.22

3-ethyl heptane 15869-80-4 128.26 Exp 0 7 b 1.10 0.68 0.33 0.49±0.22
Table B-1 (continued)

179

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

cis-hydrindane; 

bicyclo[4.3.0]nonane

496-10-6 124.22 AdjP 0 7 b 1.31 0.76 0.32 0.52±0.28

C9 bicycloalkanes 124.22 LM 0 8 b 1.39 0.80 0.39 0.58±0.26

1,2,3-trimethyl cyclohexane 1678-97-3 126.24 AdjP 0 7 b 1.22 0.75 0.33 0.52±0.26

1,3,5-trimethyl cyclohexane 1839-63-0 126.24 Exp 0 7 b 1.15 0.66 0.28 0.46±0.24

1,1,3-trimethyl cyclohexane 3073-66-3 126.24 Exp 1 0 6 b 1.19 0.68 0.31 0.48±0.23

1-ethyl-4-methyl cyclohexane 3728-56-1 126.24 AdjP 0 7 b 1.44 0.82 0.38 0.59±0.28

propyl cyclohexane 1678-92-8 126.24 Exp 0 7 b 1.29 0.76 0.38 0.55±0.24

C9 cycloalkanes 126.24 LM 0 8 b 1.36 0.79 0.38 0.57±0.26

Unspeciated C9 Alkanes 127.59 Mix 0 8 1.09 0.67 0.31 0.47±0.22

n-decane 124-18-5 142.28 Exp 1 0,+ 6 b 0.68 0.47 0.184 0.30±0.17

branched C10 alkanes 142.28 LM 0 8 b 0.94 0.58 0.26 0.40±0.20

2,4,6-trimethyl heptane 2613-61-8 142.28 Exp 0 7 b 1.28 0.72 0.34 0.52±0.23

2,4-dimethyl octane 4032-94-4 142.28 Exp 0 7 b 1.03 0.62 0.28 0.44±0.21

2,6-dimethyl octane 2051-30-1 142.28 Exp 1 2 0,+ 2 b 1.08 0.64 0.31 0.46±0.21

2-methyl nonane 871-83-0 142.28 Exp 1 2 0,+ 2 b 0.73 0.49 0.195 0.32±0.18

3,4-diethyl hexane 19398-77-7 142.28 Exp 1 2 0,+ 2 b 0.89 0.55 0.28 0.40±0.17

3-methyl nonane 5911-04-6 142.28 Exp 0 7 b 0.75 0.50 0.20 0.33±0.18

4-methyl nonane 17301-94-9 142.28 Exp 0 7 b 0.86 0.55 0.24 0.38±0.19

4-propyl heptane 3178-29-8 142.28 Exp 0 7 b 1.02 0.62 0.29 0.44±0.21

2,4,4-trimethyl heptane 142.28 Exp 0 7 b 1.31 0.72 0.37 0.54±0.22

2,5,5-trimethyl heptane 142.28 Exp 0 7 b 1.25 0.72 0.38 0.54±0.21

3,3-dimethyl octane 4110-44-5 142.28 Exp 0 7 b 1.09 0.65 0.33 0.48±0.20

4,4-dimethyl octane 15869-95-1 142.28 Exp 0 7 b 1.14 0.67 0.33 0.49±0.21

2,2-dimethyl octane 15869-87-1 142.28 Exp 0 7 b 0.83 0.50 0.23 0.35±0.16

2,2,4-trimethyl heptane 14720-74-2 142.28 Exp 0 7 b 1.16 0.64 0.31 0.47±0.20

2,2,5-trimethyl heptane 142.28 Exp 0 7 b 1.26 0.72 0.39 0.55±0.20

2,3,6-trimethyl heptane 4032-93-3 142.28 AdjP 0 7 b 0.90 0.58 0.27 0.40±0.19

2,3-dimethyl octane 7146-60-3 142.28 Exp 0 7 b 0.86 0.56 0.26 0.39±0.19

2,5-dimethyl octane 142.28 Exp 0 7 b 1.03 0.63 0.29 0.44±0.22

2-methyl-3-ethyl heptane 14676-29-0 142.28 Exp 0 7 b 0.99 0.62 0.30 0.44±0.20

4-ethyl octane 15869-86-0 142.28 AdjP 0 7 b 0.79 0.53 0.20 0.34±0.21

C10 bicycloalkanes 138.25 LM 0 8 b 1.09 0.65 0.30 0.46±0.22

isobutyl cyclohexane; (2-

methylpropyl) cyclohexane

1678-98-4 140.27 LM 0 8 b 0.99 0.61 0.28 0.43±0.21

sec-butyl cyclohexane 7058-01-7 140.27 LM 0 8 b 0.99 0.61 0.28 0.43±0.21

C10 cycloalkanes 140.27 LM 0 8 b 1.07 0.65 0.30 0.46±0.22

1,3-diethyl cyclohexane 1678-99-5 140.27 AdjP 0 7 b 1.26 0.74 0.34 0.52±0.25

1,4-diethyl cyclohexane 1679-00-1 140.27 Exp 0 7 b 1.23 0.71 0.33 0.50±0.24

1-methyl-3-isopropyl 

cyclohexane

16580-24-8 140.27 Exp 0 7 b 1.00 0.62 0.29 0.43±0.21

butyl cyclohexane 1678-93-9 140.27 Exp 1 0 6 b 0.99 0.61 0.28 0.43±0.21

unspeciated C10 alkanes 141.61 Mix 0 8 0.90 0.56 0.25 0.39±0.20

n-undecane 1120-21-4 156.31 Exp 1 0,+ 6 b 0.61 0.42 0.157 0.27±0.16

branched C11 alkanes 156.31 LM 0 8 b 0.73 0.47 0.188 0.31±0.18

2,3,4,6-tetramethyl heptane 61868-54-0 156.31 Exp 0 7 b 1.11 0.67 0.33 0.48±0.21

2,6-dimethyl nonane 17302-28-2 156.31 Exp 0 7 b 0.79 0.50 0.21 0.33±0.18

3,5-diethyl heptane 61869-02-1 156.31 Exp 0 7 b 1.11 0.66 0.30 0.46±0.23

3-methyl decane 13151-34-3 156.31 Exp 0 7 b 0.65 0.44 0.163 0.28±0.17
Table B-1 (continued)

180

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

4-methyl decane 2847-72-5 156.31 Exp 0 7 b 0.68 0.45 0.174 0.29±0.17

C11 bicycloalkanes 152.28 LM 0 8 b 0.91 0.56 0.24 0.38±0.21

C11 cycloalkanes 154.29 LM 0 8 b 0.90 0.56 0.23 0.38±0.21

1,3-diethyl-5-methyl 

cyclohexane

164259-42-1 154.29 Exp 0 7 b 1.04 0.61 0.26 0.42±0.22

1-ethyl-2-propyl cyclohexane 62238-33-9 154.29 AdjP 0 7 b 0.81 0.53 0.21 0.35±0.21

pentyl cyclohexane 4292-92-6 154.29 Exp 0 7 b 0.84 0.53 0.23 0.36±0.19

unspeciated C11 alkanes 155.64 Mix 0 8 0.74 0.48 0.193 0.32±0.18

n-dodecane 112-40-3 170.33 Exp 1 2 0,+ 3 b 0.55 0.38 0.139 0.24±0.15

branched C12 alkanes 170.33 LM 0 8 b 0.63 0.43 0.141 0.26±0.18

2,3,5,7-tetramethyl octane 62199-32-0 170.33 Exp 0 7 b 0.91 0.55 0.23 0.38±0.20

2,6-diethyl octane 62183-94-2 170.33 Exp 0 7 b 0.97 0.59 0.27 0.42±0.20

3,6-dimethyl decane 17312-53-7 170.33 AdjP 0 7 b 0.70 0.47 0.156 0.29±0.19

3-methyl undecane 1002-43-3 170.33 Exp 0 7 b 0.59 0.40 0.145 0.25±0.16

5-methyl undecane 1632-70-8 170.33 AdjP 0 7 b 0.55 0.39 0.105 0.22±0.18

C12 tricycloalkanes 164.29 LM 0 8 b 0.82 0.51 0.196 0.33±0.20

C12 bicycloalkanes 166.30 LM 0 8 b 0.81 0.50 0.194 0.33±0.20

C12 cycloalkanes 168.32 LM 0 8 b 0.80 0.49 0.192 0.32±0.19

1,3,5-triethyl cyclohexane 164259-43-2 168.32 Exp 0 7 b 1.02 0.59 0.27 0.42±0.21

1-methyl-4-pentyl cyclohexane 75736-67-3 168.32 Exp 0 7 b 0.72 0.46 0.177 0.30±0.18

hexyl cyclohexane 4292-75-5 168.32 AdjP 1 2 0 2 b 0.65 0.43 0.133 0.26±0.19

unspeciated C12 alkanes 169.66 Mix 0 8 0.66 0.44 0.157 0.28±0.18

n-tridecane 629-50-5 184.36 Exp 1 0,+ 6 b 0.53 0.37 0.133 0.23±0.15

branched C13 alkanes 184.36 LM 0 8 b 0.60 0.40 0.140 0.25±0.16

2,3,6-trimethyl 4-isopropyl 

heptane

184.36 Exp 0 7 b 0.93 0.55 0.25 0.39±0.19

2,4,6,8-tetramethyl nonane 14638-54-1 184.36 AdjP 0 7 b 0.76 0.47 0.170 0.30±0.19

3,6-dimethyl undecane 17301-28-9 184.36 Exp 0 7 b 0.69 0.44 0.175 0.29±0.17

3,7-diethyl nonane 184.36 Exp 0 7 b 0.89 0.52 0.23 0.37±0.19

3-methyl dodecane 17312-57-1 184.36 Exp 0 7 b 0.54 0.37 0.134 0.24±0.15

5-methyl dodecane 17453-93-9 184.36 AdjP 0 7 b 0.47 0.34 0.079 0.188±0.168

C13 tricycloalkanes 178.31 LM 0 8 b 0.71 0.46 0.173 0.30±0.18

C13 bicycloalkanes 180.33 LM 0 8 b 0.70 0.45 0.171 0.29±0.18

C13 cycloalkanes 182.35 LM 0 8 b 0.70 0.45 0.170 0.29±0.18

1,3-diethyl-5-propyl 

cyclohexane

182.35 Exp 0 7 b 0.96 0.56 0.25 0.39±0.20

1-methyl-2-hexyl cyclohexane 92031-93-1 182.35 Exp 0 7 b 0.58 0.40 0.144 0.25±0.17

heptyl cyclohexane 5617-41-4 182.35 AdjP 0 7 b 0.55 0.38 0.113 0.23±0.18

unspeciated C13 alkanes 183.69 Mix 0 8 0.61 0.40 0.148 0.26±0.16

n-tetradecane 629-59-4 198.39 Exp 1 2 0,+ 3 b 0.51 0.36 0.133 0.23±0.14

branched C14 alkanes 198.39 LM 0 8 b 0.55 0.37 0.130 0.23±0.15

2,4,5,6,8-pentamethyl nonane 198.39 Exp 0 7 b 0.95 0.59 0.26 0.41±0.21

2-methyl 3,5-diisopropyl 

heptane

198.39 AdjP 0 7 b 0.56 0.37 0.123 0.23±0.16

3,7-dimethyl dodecane 82144-67-0 198.39 Exp 0 7 b 0.62 0.40 0.158 0.26±0.16

3,8-diethyl decane 6224-52-8 198.39 AdjP 0 7 b 0.60 0.40 0.136 0.25±0.17

3-methyl tridecane 6418-41-3 198.39 Exp 0 7 b 0.51 0.35 0.126 0.22±0.14

6-methyl tridecane 13287-21-3 198.39 AdjP 0 7 b 0.46 0.33 0.079 0.183±0.162

C14 tricycloalkanes 192.34 LM 0 8 b 0.66 0.42 0.161 0.27±0.17
Table B-1 (continued)

181

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

C14 bicycloalkanes 194.36 LM 0 8 b 0.66 0.42 0.159 0.27±0.17

C14 cycloalkanes 196.37 LM 0 8 b 0.65 0.41 0.157 0.27±0.17

1,3-dipropyl-5-ethyl 

cyclohexane

196.37 Exp 0 7 b 0.91 0.53 0.24 0.37±0.19

trans-1-methyl-4-heptyl 

cyclohexane

205324-73-8 196.37 Exp 0 7 b 0.53 0.36 0.125 0.22±0.16

octyl cyclohexane 1795-15-9 196.37 AdjP 2 0 7 b 0.51 0.36 0.106 0.21±0.17

unspeciated C14 alkanes 197.72 Mix 0 8 0.57 0.38 0.140 0.24±0.16

n-pentadecane 629-62-9 212.41 Exp 1 4 0,+ 3 b 0.50 0.34 0.133 0.22±0.14

branched C15 alkanes 212.41 LM 0 8 b 0.50 0.34 0.119 0.21±0.15

2,6,8-trimethyl 4-isopropyl 

nonane

212.41 Exp 0 7 b 0.63 0.40 0.154 0.26±0.16

3,7-dimethyl tridecane 212.41 Exp 0 7 b 0.55 0.37 0.140 0.24±0.15

3,9-diethyl undecane 13286-72-1 212.41 Exp 0 7 b 0.51 0.35 0.128 0.22±0.14

3-methyl tetradecane 18435-22-8 212.41 Exp 0 7 b 0.48 0.33 0.122 0.21±0.14

6-methyl tetradecane 26730-16-5 212.41 AdjP 0 7 b 0.42 0.31 0.072 0.169±0.153

C15 tricycloalkanes 206.37 LM 0 8 b 0.63 0.40 0.154 0.26±0.16

C15 bicycloalkanes 208.38 LM 0 8 b 0.62 0.40 0.152 0.26±0.16

C15 cycloalkanes 210.40 LM 0 8 b 0.61 0.39 0.151 0.26±0.16

1,3,5-tripropyl cyclohexane 210.40 Exp 0 7 b 0.87 0.50 0.23 0.36±0.18

1-methyl-2-octyl cyclohexane 210.40 AdjP 0 7 b 0.50 0.35 0.127 0.22±0.15

nonyl cyclohexane 2883-02-5 210.40 AdjP 0 7 b 0.47 0.33 0.093 0.193±0.157

1,3-diethyl-5-pentyl 

cyclohexane

210.40 Exp 0 7 b 0.66 0.41 0.159 0.27±0.16

unspeciated C15 alkanes 211.74 Mix 0 8 0.54 0.36 0.134 0.23±0.15

n-C16 544-76-3 226.44 AdjP 1 3 0,+ 3 b 0.45 0.32 0.104 0.194±0.144

branched C16 alkanes 226.44 LM 0 8 b 0.47 0.33 0.120 0.21±0.13

2,7-dimethyl 3,5-diisopropyl 

heptane

226.44 AdjP 0 7 b 0.52 0.35 0.114 0.22±0.16

3-methyl pentadecane 2882-96-4 226.44 Exp 0 7 b 0.46 0.32 0.118 0.20±0.13

4,8-dimethyl tetradecane 175032-36-7 226.44 Exp 0 7 b 0.49 0.33 0.124 0.21±0.14

7-methyl pentadecane 6165-40-8 226.44 Exp 0 7 b 0.45 0.32 0.117 0.20±0.13

C16 tricycloalkanes 220.39 LM 0 8 b 0.59 0.37 0.144 0.24±0.15

C16 bicycloalkanes 222.41 LM 0 8 b 0.58 0.37 0.143 0.24±0.15

C16 cycloalkanes 224.43 LM 0 8 b 0.55 0.36 0.135 0.23±0.15

1,3-propyl-5-butyl cyclohexane 224.43 Exp 0 7 b 0.75 0.45 0.20 0.31±0.16

1-methyl-4-nonyl cyclohexane 39762-40-8 224.43 Exp 0 7 b 0.46 0.32 0.115 0.20±0.14

decyl cyclohexane 1795-16-0 224.43 AdjP 0 7 b 0.43 0.31 0.087 0.180±0.149

unspeciated C16 alkanes 225.77 Mix 0 8 0.49 0.34 0.120 0.21±0.14

n-C17 629-78-7 240.47 LM 0,+ 7 b 0.42 0.30 0.098 0.183±0.136

branched C17 alkanes 240.47 LM 0 8 b 0.44 0.31 0.113 0.194±0.126

C17 tricycloalkanes 234.42 LM 0 8 b 0.55 0.35 0.135 0.23±0.14

C17 bicycloalkanes 236.44 LM 0 8 b 0.55 0.35 0.134 0.23±0.14

C17 cycloalkanes 238.45 LM 0 8 b 0.52 0.34 0.127 0.22±0.14

unspeciated C17 alkanes 239.80 Mix 0 8 0.46 0.32 0.113 0.198±0.134

n-C18 593-45-3 254.49 LM 0,+ 7 b 0.40 0.29 0.093 0.173±0.129

branched C18 alkanes 254.49 LM 0 8 b 0.42 0.29 0.107 0.184±0.119

C18 tricycloalkanes 248.45 LM 0 8 b 0.52 0.33 0.128 0.22±0.14

C18 bicycloalkanes 250.46 LM 0 8 b 0.52 0.33 0.127 0.21±0.13
Table B-1 (continued)

182

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

C18 cycloalkanes 252.48 LM 0 8 b 0.49 0.32 0.120 0.21±0.13

unspeciated C18 alkanes 253.82 Mix 0 8 0.44 0.30 0.107 0.187±0.127

n-C19 629-92-5 268.52 LM 0,+ 7 b 0.38 0.27 0.088 0.164±0.122

branched C19 alkanes 268.52 LM 0 8 b 0.40 0.27 0.102 0.174±0.113

C19 tricycloalkanes 262.47 LM 0 8 b 0.49 0.31 0.121 0.20±0.13

C19 bicycloalkanes 264.49 LM 0 8 b 0.49 0.31 0.120 0.20±0.13

C19 cycloalkanes 266.51 LM 0 8 b 0.46 0.30 0.113 0.194±0.126

n-C20 112-95-8 282.55 LM 0,+ 7 b 0.36 0.26 0.084 0.156±0.116

branched C20 alkanes 282.55 LM 0 8 b 0.38 0.26 0.097 0.165±0.108

C20 tricycloalkanes 276.50 LM 0 8 b 0.47 0.30 0.115 0.194±0.121

C20 bicycloalkanes 278.52 LM 0 8 b 0.46 0.30 0.114 0.193±0.121

C20 cycloalkanes 280.53 LM 0 8 b 0.44 0.29 0.108 0.185±0.119

n-C21 629-94-7 296.57 LM 0,+ 7 b 0.34 0.25 0.080 0.148±0.110

branched C21 alkanes 296.57 LM 0 8 b 0.36 0.25 0.092 0.158±0.103

C21 tricycloalkanes 290.53 LM 0 8 b 0.44 0.28 0.109 0.185±0.116

C21 bicycloalkanes 292.54 LM 0 8 b 0.44 0.28 0.108 0.184±0.115

C21 cycloalkanes 294.56 LM 0 8 b 0.42 0.27 0.103 0.176±0.114

n-C22 629-97-0 310.60 LM 0,+ 7 b 0.33 0.23 0.076 0.142±0.105

branched C22 alkanes 310.60 LM 0 8 b 0.34 0.24 0.088 0.151±0.098

C22 tricycloalkanes 304.55 LM 0 8 b 0.42 0.27 0.104 0.177±0.110

C22 bicycloalkanes 306.57 LM 0 8 b 0.42 0.27 0.103 0.175±0.110

C22 cycloalkanes 308.58 LM 0 8 b 0.40 0.26 0.098 0.168±0.108

Alkenes

ethene 74-85-1 28.05 Exp 1 1 0 3 d 9.00 3.64 2.21 3.11±1.08

propene 115-07-1 42.08 Exp 1 1 0 3 d 11.66 4.44 2.73 3.85±1.38

1,2-propadiene (allene) 463-49-0 40.06 Exp 1 0 11 8.45 3.99 2.53 3.36±1.01

1-butene 106-98-9 56.11 Exp 1 3 0 3 d 9.73 3.82 2.37 3.30±1.13

C4 terminal alkenes 56.11 LM 0 7 9.73 3.82 2.37 3.30±1.13

isobutene 115-11-7 56.11 Exp 1 3 0 3 6.29 2.16 1.18 1.83±0.83

cis-2-butene 590-18-1 56.11 Exp 1 0 6 14.24 5.08 3.08 4.45±1.78

trans-2-butene 624-64-6 56.11 Exp 1 1 0 3 15.16 5.30 3.16 4.63±1.93

C4 internal alkenes 56.11 LM 0 7 14.70 5.19 3.12 4.54±1.85

1,2-butadiene 590-19-2 54.09 Exp 1 0 11 9.35 4.02 2.53 3.43±1.08

1,3-butadiene 106-99-0 54.09 Exp 1 0 6 12.61 4.71 2.88 4.07±1.46

C4 alkenes 56.11 LM 0 8 12.22 4.51 2.74 3.92±1.48

1-pentene 109-67-1 70.13 Exp 1 0 6 d 7.21 2.88 1.78 2.47±0.84

3-methyl-1-butene 563-45-1 70.13 Exp 1 0 6 d 6.99 2.81 1.74 2.41±0.81

C5 terminal alkenes 70.13 LM 0 7 7.21 2.88 1.78 2.47±0.84

2-methyl-1-butene 563-46-2 70.13 Exp 1 0 8 6.40 2.30 1.31 1.96±0.81

2-methyl-2-butene 513-35-9 70.13 Exp 1 0 6 14.08 4.57 2.57 3.99±1.96

cis-2-pentene 627-20-3 70.13 Exp 1 0 6 10.38 3.94 2.45 3.44±1.22

trans-2-pentene 646-04-8 70.13 Exp 1 0 6 10.56 3.97 2.45 3.46±1.25

2-pentenes 70.13 LM 0 7 10.47 3.95 2.45 3.45±1.24

C5 internal alkenes 70.13 LM 0 7 10.47 3.95 2.45 3.45±1.24

cyclopentene 142-29-0 68.12 Exp 1 0 8 6.77 2.53 1.55 2.20±0.80

trans-1,3-pentadiene 2004-70-8 68.12 Exp 0 8 12.50 4.76 2.95 4.12±1.43

cis-1,3-pentadiene 1574-41-0 68.12 LM 0 8 12.50 4.76 2.95 4.12±1.43

1,4-pentadiene 591-93-5 68.12 Exp 1 0 8 9.24 3.73 2.40 3.25±1.03
Table B-1 (continued)

183

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

1,2-pentadiene 591-95-7 68.12 Exp 1 0 11 7.86 3.23 2.00 2.76±0.90

3-methyl-1,2-butadiene 598-25-4 68.12 Exp 1 0 11 10.29 3.98 2.44 3.43±1.18

isoprene (2-methyl-1,3-

butadiene)

78-79-5 68.12 Exp 1 2 0 1 10.61 3.92 2.35 3.37±1.25

cyclopentadiene 542-92-7 66.10 LM 0 8 6.98 2.61 1.59 2.27±0.82

C5 alkenes 70.13 LM 0 8 8.84 3.42 2.11 2.96±1.04

1-hexene 592-41-6 84.16 Exp 1 4 0 4 d 5.49 2.33 1.45 1.98±0.65

3,3-dimethyl-1-butene 558-37-2 84.16 Exp 1 0 8 d 5.82 2.42 1.51 2.07±0.67

3-methyl-1-pentene 760-20-3 84.16 Exp 0 8 6.14 2.52 1.56 2.15±0.72

4-methyl-1-pentene 691-37-2 84.16 Exp 0 8 5.68 2.30 1.40 1.96±0.67

C6 terminal alkenes 84.16 LM 0 8 5.49 2.33 1.45 1.98±0.65

2,3-dimethyl-1-butene 563-78-0 84.16 Exp 0 8 4.75 1.75 0.99 1.48±0.60

2-ethyl-1-butene 760-21-4 84.16 Exp 0 8 5.07 1.85 1.05 1.57±0.64

2-methyl-1-pentene 763-29-1 84.16 Exp 1 0 8 5.26 1.90 1.07 1.61±0.67

2,3-dimethyl-2-butene 563-79-1 84.16 Exp 1 0 8 12.49 3.78 1.96 3.28±1.91

2-methyl-2-pentene 625-27-4 84.16 Exp 1 0 8 11.00 3.75 2.15 3.25±1.46

cis 4-methyl-2-pentene 84.16 LM 0 8 8.12 3.11 1.92 2.70±0.97

cis-2-hexene 7688-21-3 84.16 Exp 0 8 8.31 3.20 1.98 2.78±0.98

cis-3-hexene 7642-09-3 84.16 Exp 0 8 7.61 3.07 1.94 2.66±0.88

cis-3-methyl-2-pentene 922-62-3 84.16 Exp 0 8 12.49 4.22 2.42 3.67±1.69

trans-3-methyl-2-pentene 616-12-6 84.16 Exp 0 8 13.17 4.42 2.52 3.84±1.78

trans-4-methyl-2-pentene 674-76-0 84.16 Exp 1 0 8 8.12 3.11 1.92 2.70±0.97

trans-2-hexene 4050-45-7 84.16 Exp 0 8 8.62 3.24 1.99 2.82±1.03

trans-3-hexene 13269-52-8 84.16 Exp 0 8 7.57 3.04 1.92 2.63±0.88

2-hexenes 592-43-8 84.16 LM 0 8 8.47 3.22 1.99 2.80±1.00

C6 internal alkenes 84.16 LM 0 8 8.47 3.22 1.99 2.80±1.00

3-methyl cyclopentene 1120-62-3 82.14 Exp 0 8 5.10 2.05 1.29 1.77±0.60

1-methyl cyclopentene 693-89-0 82.14 AdjP 0 8 12.49 4.32 2.49 3.74±1.63

cyclohexene 110-83-8 82.14 Exp 1 4 0 4 5.00 2.04 1.29 1.76±0.59

trans,trans-2,4-hexadiene 5194-51-4 82.14 LM 0 8 8.83 3.32 2.04 2.89±1.06

trans-1,3-hexadiene 20237-34-7 82.14 LM 0 8 10.37 3.95 2.45 3.42±1.19

trans-1,4-hexadiene 7319-00-8 82.14 Exp 1 0 8 8.64 3.33 2.06 2.88±1.01

C6 cyclic olefins or di-olefins 82.14 LM 0 8 8.68 3.30 2.04 2.87±1.03

C6 alkenes 84.16 LM 0 8 6.98 2.77 1.72 2.39±0.82

1-methyl cyclohexene 591-49-1 96.17 Exp 1 0 8 6.61 2.44 1.41 2.08±0.86

4-methyl cyclohexene 591-47-9 96.17 Exp 0 8 4.18 1.71 1.07 1.47±0.50

C7 cyclic olefins or di-olefins 96.17 LM 0 8 7.29 2.83 1.74 2.44±0.88

1-heptene 592-76-7 98.19 AdjP 1 0 8 d 4.43 1.91 1.14 1.59±0.54

3,4-dimethyl-1-pentene 7385-78-6 98.19 Exp 0 8 4.84 2.00 1.21 1.69±0.57

3-methyl-1-hexene 3404-61-3 98.19 Exp 0 8 4.41 1.92 1.15 1.60±0.54

2,4-dimethyl-1-pentene 2213-32-3 98.19 AdjP 0 8 6.01 2.39 1.42 2.02±0.72

2,3-dimethyl-1-pentene 3404-72-6 98.19 Exp 0 8 5.15 2.12 1.24 1.77±0.64

3,3-dimethyl-1-pentene 3404-73-7 98.19 Exp 0 8 4.91 2.17 1.39 1.85±0.56

2-methyl-1-hexene 6094-02-6 98.19 Exp 0 8 5.10 2.11 1.22 1.75±0.64

2,3,3-trimethyl-1-butene 594-56-9 98.19 Exp 0 8 4.49 1.78 1.06 1.51±0.54

4,4-dimethyl-cis-2-pentene 762-63-0 98.19 Exp 0 8 6.64 2.54 1.53 2.19±0.81

2,4-dimethyl-2-pentene 625-65-0 98.19 Exp 0 8 9.29 3.15 1.79 2.73±1.25

2-methyl-2-hexene 2738-19-4 98.19 Exp 0 8 9.47 3.21 1.81 2.77±1.28

3-ethyl-2-pentene 816-79-5 98.19 Exp 0 8 9.75 3.43 1.99 2.97±1.31
Table B-1 (continued)

184

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

3-methyl-trans-3-hexene 3899-36-3 98.19 Exp 0 8 9.72 3.45 2.01 2.98±1.26

cis-2-heptene 6443-92-1 98.19 Exp 0 8 7.16 2.78 1.70 2.40±0.86

2-methyl-trans-3-hexene 692-24-0 98.19 Exp 0 8 6.25 2.55 1.60 2.20±0.73

3-methyl-cis-3-hexene 4914-89-0 98.19 Exp 0 8 9.72 3.45 2.01 2.98±1.26

3,4-dimethyl-cis-2-pentene 4914-91-4 98.19 Exp 0 8 9.15 3.10 1.72 2.66±1.28

2,3-dimethyl-2-pentene 10574-37-5 98.19 Exp 1 0 8 9.74 3.11 1.65 2.67±1.43

cis-3-heptene 7642-10-6 98.19 Exp 0 8 6.33 2.58 1.62 2.22±0.74

trans-4,4-dimethyl-2-pentene 690-08-4 98.19 Exp 1 0 8 6.64 2.54 1.54 2.19±0.81

trans-2-heptene 14686-13-6 98.19 Exp 1 0 8 7.14 2.77 1.70 2.39±0.86

trans-3-heptene 14686-14-7 98.19 Exp 0 8 6.32 2.57 1.62 2.22±0.74

cis-3-methyl-2-hexene 10574-36-4 98.19 Exp 0 8 10.07 3.46 1.975 2.99±1.36

trans-4-methyl-2-hexene 98.19 Exp 0 8 7.18 2.78 1.71 2.40±0.86

trans-3-methyl-2-hexene 98.19 Exp 0 8 10.07 3.46 1.98 2.99±1.36

2-heptenes 98.19 LM 0 8 6.32 2.58 1.62 2.22±0.74

C7 terminal alkenes 98.19 LM 0 8 4.43 1.91 1.14 1.59±0.54

C7 internal alkenes 98.19 LM 0 8 6.32 2.57 1.62 2.22±0.74

C7 alkenes 98.19 LM 0 8 5.37 2.24 1.38 1.91±0.64

1,2-dimethyl cyclohexene 1674-10-8 110.20 Exp 0 8 5.63 2.09 1.11 1.73±0.78

C8 cyclic olefins or di-olefins 110.20 LM 0 8 4.89 2.02 1.21 1.70±0.61

1-octene 111-66-0 112.21 Exp 0 8 3.25 1.42 0.82 1.16±0.42

2,4,4-trimethyl-1-pentene 107-39-1 112.21 Exp 0 8 3.34 1.23 0.66 1.02±0.43

3-methyl-2-isopropyl-1-butene 111823-35-9 112.21 AdjP 0 8 3.31 1.40 0.78 1.14±0.43

trans-2-octene 13389-42-9 112.21 Exp 0 8 6.00 2.33 1.42 2.00±0.73

2-methyl-2-heptene 627-97-4 112.21 Exp 0 8 8.33 2.86 1.60 2.45±1.13

cis-4-octene 7642-15-1 112.21 AdjP 0 8 4.73 1.97 1.18 1.65±0.59

trans-2,2-dimethyl 3-hexene 690-93-7 112.21 Exp 0 8 5.00 2.11 1.32 1.80±0.60

trans-2,5-dimethyl 3-hexene 692-70-6 112.21 AdjP 0 8 4.82 2.04 1.29 1.75±0.57

trans-3-octene 14919-01-8 112.21 AdjP 0 8 5.34 2.22 1.37 1.89±0.65

trans-4-octene 14850-23-8 112.21 AdjP 1 0 8 4.81 1.98 1.18 1.67±0.59

2,4,4-trimethyl-2-pentene 107-40-4 112.21 Exp 0 8 6.29 2.23 1.24 1.89±0.84

2,3-dimethyl-2-hexene 112.21 Exp 0 8 8.53 2.74 1.44 2.35±1.25

3-octenes 112.21 LM 0 8 5.34 2.22 1.37 1.89±0.65

C8 terminal alkenes 112.21 LM 0 8 3.25 1.42 0.82 1.16±0.42

C8 internal alkenes 112.21 LM 0 8 4.81 1.98 1.18 1.67±0.59

C8 alkenes 112.21 LM 0 8 4.03 1.70 1.00 1.41±0.51

1-nonene 124-11-8 126.24 Exp 0 8 2.60 1.16 0.65 0.94±0.35

C9 terminal alkenes 126.24 LM 0 8 2.60 1.16 0.65 0.94±0.35

4,4-dimethyl-1-pentene 762-62-9 126.24 Exp 0 8 3.13 1.34 0.77 1.10±0.40

4-nonene 2198-23-4 126.24 LM 0 8 4.54 1.90 1.15 1.60±0.56

3-nonenes 126.24 LM 0 8 4.54 1.90 1.15 1.60±0.56

C9 internal alkenes 126.24 LM 0 8 4.54 1.90 1.15 1.60±0.56

trans-4-nonene 10405-85-3 126.24 AdjP 0 8 4.54 1.90 1.15 1.60±0.56

C9 cyclic olefins or di-olefins 124.22 LM 0 8 4.62 1.93 1.17 1.63±0.57

C9 alkenes 126.24 LM 0 8 3.57 1.53 0.90 1.27±0.45

1-decene 872-05-9 140.27 Exp 0 8 2.17 0.98 0.54 0.78±0.30

C10 terminal alkenes 140.27 LM 0 8 2.17 0.98 0.54 0.78±0.30

3,4-diethyl-2-hexene 59643-70-8 140.27 Exp 0 8 3.38 1.50 0.85 1.22±0.46

cis-5-decene 7433-78-5 140.27 AdjP 0 8 3.66 1.57 0.91 1.29±0.48

trans-4-decene 19398-89-1 140.27 AdjP 0 8 3.87 1.64 0.98 1.37±0.49
Table B-1 (continued)

185

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

C10 3-alkenes 140.27 LM 0 8 3.87 1.64 0.98 1.37±0.49

C10 internal alkenes 140.27 LM 0 8 3.87 1.64 0.98 1.37±0.49

C10 cyclic olefins or di-olefins 138.25 LM 0 8 3.93 1.67 0.99 1.39±0.50

3-carene 13466-78-9 136.23 Exp 1 3 0 4 3.24 1.28 0.75 1.08±0.40

alpha-pinene 80-56-8 136.23 Exp 1 2 0 4 4.51 1.65 0.89 1.38±0.60

beta-pinene 127-91-3 136.23 Exp 1 2 0 4 3.52 1.44 0.79 1.17±0.46

d-limonene 5989-27-5 136.23 Exp 1 2 0 4 4.55 1.70 0.96 1.44±0.60

sabinene 3387-41-5 136.23 Exp 1 3 0 4 4.19 1.70 0.97 1.41±0.53

Terpinolene 586-62-9 136.23 Exp 0 8 6.36 2.22 1.18 1.88±0.93

Camphene 79-92-5 136.23 LM 0 8 4.51 1.65 0.89 1.38±0.60

terpene (monoterpenes) 136.23 LM 0 8 4.04 1.55 0.86 1.29±0.52

C10 alkenes 140.27 LM 0 8 3.31 1.42 0.83 1.17±0.43

1-undecene 821-95-4 154.29 Exp 0 8 1.87 0.86 0.46 0.67±0.27

C11 terminal alkenes 154.29 LM 0 8 1.87 0.86 0.46 0.67±0.27

trans-5-undecene 764-97-6 154.29 AdjP 0 8 3.60 1.54 0.92 1.28±0.46

C11 3-alkenes 154.29 LM 0 8 3.60 1.54 0.92 1.28±0.46

C11 internal alkenes 154.29 LM 0 8 3.60 1.54 0.92 1.28±0.46

C11 cyclic olefins or di-olefins 152.28 LM 0 8 3.65 1.56 0.93 1.30±0.47

C11 alkenes 154.29 LM 0 8 2.73 1.20 0.69 0.98±0.36

C12 terminal alkenes 168.32 LM 0 8 1.64 0.76 0.41 0.60±0.24

1-dodecene 112-41-4 168.32 Exp 0 8 1.64 0.76 0.41 0.60±0.24

C12 2-alkenes 168.32 LM 0 8 3.14 1.36 0.79 1.12±0.41

C12 3-alkenes 168.32 LM 0 8 3.14 1.36 0.79 1.12±0.41

C12 internal alkenes 168.32 LM 0 8 3.14 1.36 0.79 1.12±0.41

trans-5-dodecene 7206-16-8 168.32 AdjP 0 8 3.14 1.36 0.79 1.12±0.41

C12 cyclic olefins or di-olefins 166.30 LM 0 8 3.18 1.37 0.80 1.13±0.42

C12 alkenes 168.32 LM 0 8 2.39 1.06 0.60 0.86±0.32

1-tridecene 2437-56-1 182.35 Exp 0 8 1.48 0.69 0.37 0.54±0.22

C13 terminal alkenes 182.35 LM 0 8 1.48 0.69 0.37 0.54±0.22

trans-5-tridecene 23051-84-5 182.35 Exp 0 8 2.59 1.13 0.67 0.93±0.35

C13 3-alkenes 182.35 LM 0 8 2.59 1.13 0.67 0.93±0.35

C13 internal alkenes 182.35 LM 0 8 2.59 1.13 0.67 0.93±0.35

C13 cyclic olefins or di-olefins 180.33 LM 0 8 2.62 1.14 0.67 0.94±0.35

C13 alkenes 182.35 LM 0 8 2.03 0.91 0.52 0.74±0.28

1-tetradecene 1120-36-1 196.37 Exp 0 8 1.34 0.63 0.33 0.49±0.20

C14 terminal alkenes 196.37 LM 0 8 1.34 0.63 0.33 0.49±0.20

trans-5-tetradecene 41446-66-6 196.37 Exp 0 8 2.35 1.03 0.61 0.85±0.32

C14 3-alkenes 196.37 LM 0 8 2.35 1.03 0.61 0.85±0.32

C14 internal alkenes 196.37 LM 0 8 2.35 1.03 0.61 0.85±0.32

C14 cyclic olefins or di-olefins 194.36 LM 0 8 2.38 1.04 0.61 0.86±0.33

C14 alkenes 196.37 LM 0 8 1.85 0.83 0.47 0.67±0.26

1-pentadecene 13360-61-7 210.40 LM 0 8 1.25 0.59 0.31 0.46±0.19

C15 terminal alkenes 210.40 LM 0 8 1.25 0.59 0.31 0.46±0.19

trans-5-pentadecene 74392-33-9 210.40 Exp 0 8 2.16 0.95 0.56 0.78±0.30

C15 3-alkenes 210.40 LM 0 8 2.16 0.95 0.56 0.78±0.30

C15 internal alkenes 210.40 LM 0 8 2.16 0.95 0.56 0.78±0.30

C15 cyclic olefins or di-olefins 208.38 LM 0 8 2.19 0.96 0.56 0.79±0.30

C15 alkenes 210.40 LM 0 8 1.71 0.77 0.43 0.62±0.24
Table B-1 (continued)

186

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

Aromatic Hydrocarbons

benzene 71-43-2 78.11 Exp 1 2 0? 4 0.72 0.101 -0.159 -.008±0.185

toluene 108-88-3 92.14 Exp 1 2 0 4 4.00 1.36 0.52 1.02±0.60

ethyl benzene 100-41-4 106.17 Exp 1 3 0 4 3.04 1.15 0.50 0.88±0.44

m-xylene 108-38-3 106.17 Exp 1 1 0 4 9.75 3.09 1.48 2.53±1.30

o-xylene 95-47-6 106.17 Exp 1 2 0 4 7.64 2.51 1.16 2.02±1.04

p-xylene 106-42-3 106.17 Exp 1 3 0 4 5.84 1.93 0.82 1.51±0.82

C8 disubstituted benzenes 1330-20-7 106.17 LM 0 8 7.76 2.51 1.15 2.02±1.05

isomers of ethylbenzene 106.17 LM 0 8 6.57 2.17 0.99 1.73±0.90

styrene 100-42-5 104.15 Exp 1 2 0 2 1.73 0.21 -0.48 -.107±0.500

Unspeciated C8 Aromatics 106.17 Mix 0 8 7.64 2.49 1.15 2.01±1.03

C9 monosubstituted benzenes 120.19 LM 0 8 2.03 0.82 0.36 0.62±0.30

n-propyl benzene 103-65-1 120.19 Exp 1 0 8 2.03 0.82 0.36 0.62±0.30

isopropyl benzene (cumene) 98-82-8 120.19 Exp 1 0 8 2.52 0.94 0.39 0.71±0.37

C9 disubstituted benzenes 120.19 LM 0 8 5.81 1.95 0.89 1.55±0.79

m-ethyl toluene 620-14-4 120.19 Exp 1 0 8 7.39 2.40 1.13 1.95±0.99

o-ethyl toluene 611-14-3 120.19 Exp 1 0 8 5.59 1.90 0.87 1.51±0.76

p-ethyl toluene 622-96-8 120.19 Exp 1 0 8 4.44 1.54 0.67 1.20±0.62

C9 trisubstituted benzenes 25551-13-7 120.19 LM 0 8 10.87 3.59 1.94 3.04±1.38

1,2,3-trimethyl benzene 526-73-8 120.19 Exp 1 2 0 4 11.97 3.93 2.12 3.33±1.52

1,2,4-trimethyl benzene 95-63-6 120.19 Exp 1 2 0 4 8.87 3.05 1.65 2.56±1.12

1,3,5-trimethyl benzene 108-67-8 120.19 Exp 1 2 0 4 11.76 3.80 2.05 3.24±1.51

isomers of propyl benzene 120.19 LM 0 8 6.23 2.12 1.06 1.74±0.82

indene 95-13-6 116.16 LM 0 10 1.55 0.191 -0.43 -.095±0.448

indane 496-11-7 118.18 LM 0 10 3.32 1.18 0.47 0.89±0.48

allylbenzene 300-57-2 118.18 LM 0 8 1.53 0.188 -0.43 -.094±0.441

α-methyl styrene 98-83-9 118.18 LM 0 8 1.53 0.188 -0.43 -.094±0.441

C9 styrenes 118.18 LM 0 8 1.53 0.188 -0.43 -.094±0.441

β-methyl styrene 637-50-3 118.18 Exp 1 0 8 1.01 0.155 -0.32 -.074±0.300

Unspeciated C9 Aromatics 120.09 Mix 0 8 7.99 2.68 1.38 2.23±1.03

C10 monosubstituted benzenes 134.22 Exp 0 8 2.36 0.94 0.42 0.72±0.34

n-butyl benzene 104-51-8 134.22 LM 0 8 2.36 0.94 0.42 0.72±0.34

sec-butyl benzene 135-98-8 134.22 LM 0 8 2.36 0.94 0.42 0.72±0.34

tert-butyl benzene 98-06-6 134.22 Exp 1 0 8 1.95 0.70 0.27 0.52±0.30

o-cymene; 1-methyl-2-(1-

methylethyl) benzene

527-84-4 134.22 LM 0 8 5.49 1.87 0.89 1.51±0.74

1-methyl-2-n-propyl benzene 1074-17-5 134.22 LM 0 8 5.49 1.87 0.89 1.51±0.74

m-cymene; 1-methyl-3-(1-

methylethyl) benzene

535-77-3 134.22 LM 0 8 7.10 2.30 1.12 1.89±0.94

1-methyl-3-n-propyl benzene 1074-43-7 134.22 LM 0 8 7.10 2.30 1.12 1.89±0.94

1-methyl-4-n-propyl benzene 1074-55-1 134.22 LM 0 8 4.43 1.54 0.71 1.22±0.61

C10 disubstituted benzenes 134.22 LM 0 8 5.68 1.91 0.91 1.54±0.76

m-C10 disubstituted benzenes 134.22 Exp 0 8 7.10 2.30 1.12 1.89±0.94

o-C10 disubstituted benzenes 134.22 Exp 0 8 5.49 1.87 0.89 1.51±0.74

p-C10 disubstituted benzenes 134.22 Exp 0 8 4.43 1.54 0.71 1.22±0.61

m-diethyl benzene 141-93-5 134.22 LM 0 8 7.10 2.30 1.12 1.89±0.94

o-diethyl benzene 135-01-3 134.22 LM 0 8 5.49 1.87 0.89 1.51±0.74

1-methyl-4-isopropyl benzene 

(p-cymene)

99-87-6 134.22 Exp 1 0 8 4.44 1.52 0.67 1.19±0.61
Table B-1 (continued)

187

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

p-diethyl benzene 105-05-5 134.22 LM 0 8 4.43 1.54 0.71 1.22±0.61

1,2,3-C10 trisubstituted 

benzenes

134.22 Exp 0 8 10.15 3.37 1.81 2.85±1.29

1,2,4-C10 trisubstituted 

benzenes

134.22 Exp 0 8 7.55 2.62 1.41 2.19±0.96

1,3,5-C10 trisubstituted 

benzenes

134.22 Exp 0 8 10.08 3.28 1.77 2.79±1.29

1,2,3,4-tetramethyl benzene 488-23-3 134.22 LM 0 8 9.26 3.09 1.67 2.61±1.18

1,2,4,5-tetramethyl benzene 95-93-2 134.22 LM 0 8 9.26 3.09 1.67 2.61±1.18

1,2-dimethyl-3-ethyl benzene 933-98-2 134.22 LM 0 8 10.15 3.37 1.81 2.85±1.29

1,2-dimethyl-4-ethyl benzene 934-80-5 134.22 LM 0 8 7.55 2.62 1.41 2.19±0.96

1,3-dimethyl-2-ethyl benzene 2870-04-4 134.22 LM 0 8 10.15 3.37 1.81 2.85±1.29

1,3-dimethyl-4-ethyl benzene 874-41-9 134.22 LM 0 8 7.55 2.62 1.41 2.19±0.96

1,3-dimethyl-5-ethyl benzene 934-74-7 134.22 LM 0 8 10.08 3.28 1.77 2.79±1.29

1,4-dimethyl-2-ethyl benzene 1758-88-9 134.22 LM 0 8 7.55 2.62 1.41 2.19±0.96

1,2,3,5-tetramethyl benzene 527-53-7 134.22 LM 0 8 9.26 3.09 1.67 2.61±1.18

C10 trisubstituted benzenes 134.22 LM 0 8 9.26 3.09 1.67 2.61±1.18

C10 tetrasubstituted benzenes 134.22 LM 0 8 9.26 3.09 1.67 2.61±1.18

butylbenzenes 134.22 LM 0 8 5.76 1.98 1.00 1.62±0.75

methyl indanes 132.20 LM 0 10 2.97 1.05 0.42 0.80±0.43

tetralin (1,2,3,4-

tetrahydronaphthalene)

119-64-2 132.20 Exp 1 4 + 5 2.97 1.05 0.42 0.80±0.43

naphthalene 91-20-3 128.17 Exp 1 4 + 5 3.34 1.14 0.49 0.90±0.46

C10 styrenes 132.20 LM 0 8 1.37 0.168 -0.38 -.084±0.394

Unspeciated C10 Aromatics 133.91 Mix 0 8 7.07 2.37 1.22 1.97±0.92

n-pentyl benzene 538-68-1 148.24 LM 0 8 2.12 0.86 0.40 0.66±0.30

C11 monosubstituted benzenes 148.24 Exp 0 8 2.12 0.86 0.40 0.66±0.30

m-C11 disubstituted benzenes 148.24 Exp 0 8 6.15 2.02 0.99 1.66±0.82

o-C11 disubstituted benzenes 148.24 Exp 0 8 4.73 1.64 0.79 1.32±0.63

p-C11 disubstituted benzenes 148.24 Exp 0 8 3.88 1.38 0.64 1.09±0.53

1-butyl-2-methyl benzene 148.24 LM 0 8 4.73 1.64 0.79 1.32±0.63

1-ethyl-2-n-propyl benzene 148.24 LM 0 8 4.73 1.64 0.79 1.32±0.63

o-tert-butyl toluene; 1-(1,1-

dimethylethyl)-2-methyl 

benzene

1074-92-6 148.24 LM 0 8 4.73 1.64 0.79 1.32±0.63

1-methyl-3-n-butyl benzene 1595-04-6 148.24 LM 0 8 6.15 2.02 0.99 1.66±0.82

p-isobutyl toluene; 1-methyl-4-

(2-methylpropyl) benzene

5161-04-6 148.24 LM 0 8 3.88 1.38 0.64 1.09±0.53

C11 disubstituted benzenes 148.24 LM 0 8 4.92 1.68 0.81 1.36±0.66

1,2,3-C11 trisubstituted 

benzenes

148.24 Exp 0 8 8.88 2.96 1.60 2.50±1.13

1,2,4-C11 trisubstituted 

benzenes

148.24 Exp 0 8 6.62 2.31 1.25 1.94±0.84

1,3,5-C11 trisubstituted 

benzenes

148.24 Exp 0 8 8.90 2.91 1.57 2.47±1.14

pentamethyl benzene 700-12-9 148.24 LM 0 8 8.13 2.73 1.47 2.30±1.03

1-methyl-3,5-diethyl benzene 2050-24-0 148.24 LM 0 8 8.90 2.91 1.57 2.47±1.14

C11 trisubstituted benzenes 148.24 LM 0 8 8.13 2.73 1.47 2.30±1.03

C11 tetrasubstituted benzenes 148.24 LM 0 8 8.13 2.73 1.47 2.30±1.03
Table B-1 (continued)

188

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

C11 pentasubstituted benzenes 148.24 LM 0 8 8.13 2.73 1.47 2.30±1.03

pentyl benzenes 148.24 LM 0 8 4.90 1.71 0.87 1.40±0.64

C11 tetralins or indanes 146.23 LM + 10 2.69 0.95 0.38 0.72±0.39

methyl naphthalenes 1321-94-4 142.20 Exp + 10 3.06 1.02 0.42 0.79±0.43

1-methyl naphthalene 90-12-0 142.20 LM + 10 3.06 1.02 0.42 0.79±0.43

2-methyl naphthalene 91-57-6 142.20 LM + 10 3.06 1.02 0.42 0.79±0.43

Unspeciated C11 Aromatics 147.72 Mix 0 8 6.95 2.34 1.23 1.96±0.89

C12 monosubstituted benzenes 162.27 Exp 0 8 1.90 0.79 0.37 0.61±0.27

m-C12 disubstituted benzenes 162.27 Exp 0 8 5.49 1.81 0.89 1.49±0.73

o-C12 disubstituted benzenes 162.27 Exp 0 8 4.23 1.48 0.71 1.19±0.57

p-C12 disubstituted benzenes 162.27 Exp 0 8 3.49 1.25 0.59 0.99±0.47

1,3-di-n-propyl benzene 162.27 LM 0 8 4.23 1.48 0.71 1.19±0.57

1,4 di-isopropyl benzene 162.27 LM 0 8 3.49 1.25 0.59 0.99±0.47

3-isopropyl cumene; 1,3-diisopropyl benzene99-62-7 162.27 LM 0 8 5.49 1.81 0.89 1.49±0.73

C12 disubstituted benzenes 162.27 LM 0 8 4.40 1.51 0.73 1.22±0.59

1,2,3-C12 trisubstituted 

benzenes

162.27 Exp 0 8 7.95 2.66 1.44 2.25±1.01

1,2,4-C12 trisubstituted 

benzenes

162.27 Exp 0 8 5.94 2.08 1.13 1.74±0.75

1,3,5-C12 trisubstituted 

benzenes

162.27 Exp 0 8 8.02 2.62 1.42 2.23±1.03

1-(1,1-dimethylethyl)-3,5-

dimethylbenzene

98-19-1 162.27 LM 0 8 8.02 2.62 1.42 2.23±1.03

C12 trisubstituted benzenes 162.27 LM 0 8 7.30 2.46 1.33 2.07±0.93

C12 tetrasubstituted benzenes 162.27 LM 0 8 7.30 2.46 1.33 2.07±0.93

C12 pentasubstituted benzenes 162.27 LM 0 8 7.30 2.46 1.33 2.07±0.93

C12 hexasubstituted benzenes 162.27 LM 0 8 7.30 2.46 1.33 2.07±0.93

hexyl benzenes 162.27 LM 0 8 4.39 1.55 0.79 1.27±0.57

C12 tetralins or indanes 160.26 LM 0 10 2.45 0.87 0.34 0.66±0.35

1-ethyl naphthalene 1127-76-0 156.22 LM + 10 2.78 0.93 0.38 0.72±0.39

C12 naphthalenes 156.22 LM + 10 3.89 1.28 0.59 1.03±0.52

C12 monosubstituted 

naphthalene

156.22 LM + 10 2.78 0.93 0.38 0.72±0.39

C12 disubstituted naphthalenes 156.22 LM + 10 4.99 1.62 0.80 1.34±0.66

2,3-dimethyl naphthalene 581-40-8 156.22 Exp 1 4 + 5 4.99 1.62 0.80 1.34±0.66

dimethyl naphthalenes 156.22 LM + 10 4.99 1.62 0.80 1.34±0.66

Unspeciated C12 Aromatics 159.90 Mix 0 8 6.02 2.02 1.06 1.69±0.77

C13 monosubstituted benzenes 176.30 Exp 0 8 1.74 0.74 0.35 0.57±0.25

m-C13 disubstituted benzenes 176.30 Exp 0 8 4.93 1.64 0.81 1.35±0.65

o-C13 disubstituted benzenes 176.30 Exp 0 8 3.78 1.34 0.65 1.08±0.50

p-C13 disubstituted benzenes 176.30 Exp 0 8 3.13 1.14 0.54 0.90±0.42

C13 disubstituted benzenes 176.30 LM 0 8 3.95 1.37 0.67 1.11±0.52

1,2,3-C13 trisubstituted 

benzenes

176.30 Exp 0 8 7.13 2.40 1.30 2.02±0.91

1,2,4-C13 trisubstituted 

benzenes

176.30 Exp 0 8 5.35 1.88 1.02 1.58±0.67

1,3,5-C13 trisubstituted 

benzenes

176.30 Exp 0 8 7.24 2.38 1.29 2.02±0.93
Table B-1 (continued)

189

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

C13 trisubstituted benzenes 176.30 LM 0 8 6.57 2.22 1.20 1.87±0.84

C13 tetralins or indanes 174.28 LM 0 10 2.25 0.80 0.32 0.61±0.33

C13 naphthalenes 170.25 LM 0 10 3.57 1.17 0.54 0.95±0.48

C13 monosubstituted 

naphthalene

170.25 LM 0 10 2.55 0.85 0.35 0.66±0.36

C13 disubstituted naphthalenes 170.25 LM 0 10 4.58 1.49 0.74 1.23±0.60

C13 trisubstituted naphthalenes 170.25 LM 0 10 4.58 1.49 0.74 1.23±0.60

Unspeciated C13 Aromatics 175.85 Mix 0 8 4.81 1.61 0.82 1.34±0.62

C14 monosubstituted benzenes 190.32 Exp 0 8 1.60 0.69 0.33 0.53±0.23

m-C14 disubstituted benzenes 190.32 Exp 0 8 4.45 1.49 0.74 1.23±0.59

o-C14 disubstituted benzenes 190.32 Exp 0 8 3.40 1.22 0.60 0.98±0.45

p-C14 disubstituted benzenes 190.32 Exp 0 8 2.84 1.04 0.50 0.83±0.38

C14 disubstituted benzenes 190.32 LM 0 8 3.56 1.25 0.61 1.01±0.47

1,2,3-C14 trisubstituted 

benzenes

190.32 Exp 0 8 6.49 2.19 1.19 1.85±0.82

1,2,4-C14 trisubstituted 

benzenes

190.32 Exp 0 8 4.89 1.73 0.94 1.45±0.62

1,3,5-C14 trisubstituted 

benzenes

190.32 Exp 0 8 6.63 2.18 1.18 1.86±0.85

C14 trisubstituted benzenes 190.32 LM 0 8 6.00 2.03 1.10 1.72±0.76

C14 tetralins or indanes 188.31 LM 0 10 2.09 0.74 0.29 0.56±0.30

C14 naphthalenes 184.28 LM 0 10 3.30 1.08 0.50 0.88±0.44

Unspeciated C14 Aromatics 189.87 Mix 0 8 3.80 1.27 0.62 1.04±0.50

C15 monosubstituted benzenes 204.35 Exp 0 8 1.48 0.64 0.32 0.50±0.21

C15 disubstituted benzenes 204.35 LM 0 8 3.25 1.15 0.57 0.93±0.43

m-C15 disubstituted benzenes 204.35 Exp 0 8 4.04 1.37 0.68 1.12±0.53

o-C15 disubstituted benzenes 204.35 Exp 0 8 3.09 1.12 0.56 0.90±0.41

p-C15 disubstituted benzenes 204.35 Exp 0 8 2.59 0.96 0.47 0.77±0.35

C15 trisubstituted benzenes 204.35 LM 0 8 5.50 1.87 1.02 1.58±0.70

1,2,3-C15 trisubstituted 

benzenes

204.35 Exp 0 8 5.94 2.01 1.09 1.70±0.75

1,2,4-C15 trisubstituted 

benzenes

204.35 Exp 0 8 4.47 1.59 0.87 1.33±0.56

1,3,5-C15 trisubstituted 

benzenes

204.35 Exp 0 8 6.10 2.01 1.09 1.71±0.78

C15 tetralins or indanes 202.34 LM 0 10 1.94 0.69 0.27 0.52±0.28

C15 naphthalenes 198.30 LM 0 10 3.06 1.01 0.47 0.81±0.41

Unspeciated C15 Aromatics 203.90 Mix 0 8 3.20 1.06 0.50 0.86±0.42

C16 monosubstituted benzenes 218.38 Exp 0 8 1.38 0.61 0.30 0.47±0.20

m-C16 disubstituted benzenes 218.38 Exp 0 8 3.71 1.26 0.63 1.04±0.49

o-C16 disubstituted benzenes 218.38 Exp 0 8 2.83 1.03 0.52 0.83±0.37

p-C16 disubstituted benzenes 218.38 Exp 0 8 2.38 0.89 0.44 0.71±0.32

C16 disubstituted benzenes 218.38 LM 0 8 2.97 1.06 0.53 0.86±0.39

1,2,3-C16 trisubstituted 

benzenes

218.38 Exp 0 8 5.46 1.86 1.01 1.57±0.69

1,2,4-C16 trisubstituted 

benzenes

218.38 Exp 0 8 4.13 1.47 0.80 1.23±0.52

1,3,5-C16 trisubstituted 

benzenes

218.38 Exp 0 8 5.63 1.86 1.01 1.58±0.72
Table B-1 (continued)

190

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

C16 trisubstituted benzenes 218.38 LM 0 8 5.07 1.73 0.94 1.46±0.64

C16 tetralins or indanes 216.36 LM 0 10 1.82 0.64 0.26 0.49±0.26

C16 naphthalenes 212.33 LM 0 10 2.86 0.94 0.43 0.76±0.38

Unspeciated C16 Aromatics 217.93 Mix 0 8 2.79 0.92 0.42 0.74±0.37

C17 monosubstituted benzenes 232.40 LM 0 8 1.30 0.57 0.29 0.44±0.18

C17 disubstituted benzenes 232.40 LM 0 8 2.79 1.00 0.50 0.81±0.37

C17 trisubstituted benzenes 232.40 LM 0 8 4.77 1.63 0.89 1.37±0.60

C17 tetralins or indanes 230.39 LM 0 10 1.70 0.60 0.24 0.46±0.25

C17 naphthalenes 226.36 LM 0 10 2.68 0.88 0.41 0.71±0.36

C18 monosubstituted benzenes 246.43 LM 0 8 1.23 0.54 0.27 0.42±0.17

C18 disubstituted benzenes 246.43 LM 0 8 2.63 0.94 0.47 0.76±0.35

C18 trisubstituted benzenes 246.43 LM 0 8 4.49 1.53 0.83 1.29±0.57

C18 tetralins or indanes 244.41 LM 0 10 1.61 0.57 0.23 0.43±0.23

C18 naphthalenes 240.38 LM 0 10 2.53 0.83 0.38 0.67±0.34

C19 monosubstituted benzenes 260.46 LM 0 8 1.16 0.51 0.25 0.40±0.16

C19 disubstituted benzenes 260.46 LM 0 8 2.49 0.89 0.44 0.72±0.33

C19 trisubstituted benzenes 260.46 LM 0 8 4.25 1.45 0.79 1.22±0.54

C19 tetralins or indanes 258.44 LM 0 10 1.52 0.54 0.21 0.41±0.22

C19 naphthalenes 254.41 LM 0 10 2.39 0.78 0.36 0.63±0.32

C20 monosubstituted benzenes 274.48 LM 0 8 1.10 0.48 0.24 0.37±0.16

C20 disubstituted benzenes 274.48 LM 0 8 2.36 0.84 0.42 0.68±0.31

C20 trisubstituted benzenes 274.48 LM 0 8 4.04 1.38 0.75 1.16±0.51

C20 tetralins or indanes 272.47 LM 0 10 1.44 0.51 0.20 0.39±0.21

C20 naphthalenes 268.44 LM 0 10 2.26 0.74 0.34 0.60±0.30

C21 monosubstituted benzenes 288.51 LM 0 8 1.05 0.46 0.23 0.36±0.15

C21 disubstituted benzenes 288.51 LM 0 8 2.25 0.80 0.40 0.65±0.30

C21 trisubstituted benzenes 288.51 LM 0 8 3.84 1.31 0.71 1.11±0.49

C21 tetralins or indanes 286.49 LM 0 10 1.37 0.49 0.193 0.37±0.20

C21 naphthalenes 282.46 LM 0 10 2.15 0.71 0.33 0.57±0.29

C22 monosubstituted benzenes 302.54 LM 0 8 1.00 0.44 0.22 0.34±0.14

C22 disubstituted benzenes 302.54 LM 0 8 2.14 0.77 0.38 0.62±0.28

C22 trisubstituted benzenes 302.54 LM 0 8 3.66 1.25 0.68 1.05±0.46

C22 tetralins or indanes 300.52 LM 0 10 1.31 0.46 0.184 0.35±0.19

C22 naphthalenes 296.49 LM 0 10 2.05 0.67 0.31 0.54±0.27

Oxygenated Organics

carbon monoxide 630-08-0 28.01 Exp 1 2 0 1 0.056 0.039 0.029 0.034±0.007

formaldehyde 50-00-0 30.03 Exp 1 1 0 1 b 9.46 2.68 1.27 2.27±1.40

methanol 67-56-1 32.04 Exp 1 3 0 2 0.67 0.31 0.190 0.26±0.08

formic acid 64-18-6 46.03 Exp 1 0 6 0.066 0.046 0.034 0.040±0.008

ethylene oxide 75-21-8 44.05 Exp 1 0 6 0.039 0.034 0.028 0.030±0.006

acetaldehyde 75-07-0 44.05 Exp 1 2 0 1 6.54 2.49 1.61 2.20±0.72

ethanol 64-17-5 46.07 Exp 1 3 0 2 1.53 0.87 0.59 0.74±0.22

dimethyl ether 115-10-6 46.07 Exp 1 3 0 2 0.81 0.56 0.44 0.50±0.08

glyoxal 107-22-2 58.04 Exp 1 0 6 12.50 3.68 1.84 3.15±1.82

methyl formate 107-31-3 60.05 Exp 1 0 6 0.057 0.046 0.037 0.041±0.007

acetic acid 64-19-7 60.05 Exp 1 0 6 0.68 0.33 0.21 0.27±0.09

glycolaldehyde 141-46-8 60.05 Exp 0 7 5.10 1.88 1.20 1.66±0.57

ethylene glycol 107-21-1 62.07 Exp 1 2 0 2 3.13 1.51 1.02 1.30±0.37
Table B-1 (continued)

191

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

glycolic acid 79-14-1 76.05 AdjP 0 8 2.38 0.89 0.47 0.72±0.33

peroxyacetic acid 79-21-0 76.05 LM 0 8 0.54 0.26 0.162 0.22±0.07

acrolein 107-02-8 56.06 Exp 1 3 0 2 7.45 2.66 1.62 2.31±0.85

trimethylene oxide 503-30-0 58.08 Exp 1 0 6 4.56 2.51 1.82 2.20±0.59

propylene oxide 75-56-9 58.08 Exp 1 0 6 0.29 0.22 0.169 0.192±0.037

propionaldehyde 123-38-6 58.08 Exp 1 0 6 7.08 2.73 1.75 2.39±0.80

acetone 67-64-1 58.08 Exp 1 1 0 2 0.36 0.147 0.089 0.124±0.041

isopropyl alcohol 67-63-0 60.10 Exp 1 2 0 2 0.61 0.36 0.25 0.31±0.07

n-propyl alcohol 71-23-8 60.10 Exp 1 0 6 2.50 1.28 0.83 1.07±0.36

acrylic acid 79-10-7 72.06 AdjP 0 8 11.38 3.84 2.18 3.31±1.45

methyl glyoxal 78-98-8 72.06 Exp 1 0 6 16.56 4.93 2.64 4.28±2.25

1,3-dioxolane 646-06-0 74.08 Exp 0 7 4.96 2.23 1.61 2.00±0.51

ethyl formate 109-94-4 74.08 Exp 1 0 6 0.48 0.29 0.21 0.25±0.07

methyl acetate 79-20-9 74.08 Exp 1 2 0 2 0.072 0.059 0.046 0.052±0.010

propionic acid 79-09-4 74.08 Exp 0 7 1.22 0.58 0.35 0.48±0.17

hydroxy acetone 116-09-6 74.08 Exp 1 0 8 3.23 1.16 0.64 0.97±0.41

propylene glycol 57-55-6 76.09 AdjP 1 2 0 2 2.58 1.17 0.76 1.01±0.30

dimethoxy methane 109-87-5 76.09 AdjP 1 0 6 0.94 0.66 0.51 0.59±0.10

2-methoxy ethanol 109-86-4 76.09 Exp 1 0 6 2.93 1.29 0.84 1.11±0.33

dimethyl carbonate 616-38-6 90.08 Exp 1 2 0 2 0.059 0.048 0.038 0.042±0.008

dihydroxy acetone 96-26-4 90.08 Exp 0 8 3.99 1.44 0.80 1.21±0.50

glycerol 56-81-5 92.09 AdjP 0 7 3.15 1.37 0.84 1.15±0.39

furan 110-00-9 68.07 Exp 1 3 - 4 9.15 3.51 2.06 2.98±1.12

crotonaldehyde 4170-30-3 70.09 Exp 1 0 8 9.39 3.26 1.94 2.84±1.11

methacrolein 78-85-3 70.09 Exp 1 2 0 2 6.01 2.15 1.33 1.88±0.68

cyclobutanone 1191-95-3 70.09 Exp 1 0 8 0.62 0.37 0.25 0.31±0.09

methylvinyl ketone 78-94-4 70.09 Exp 1 3 0 2 9.65 3.63 2.23 3.15±1.13

tetrahydrofuran 109-99-9 72.11 Exp 1 0 6 4.31 2.19 1.47 1.87±0.53

1,2-epoxy butane 106-88-7 72.11 Exp 1 0 6 0.91 0.66 0.49 0.57±0.13

2-methyl propanal 78-84-2 72.11 Exp 1 0 7 5.25 2.08 1.38 1.84±0.58

butanal 123-72-8 72.11 Exp 1 0 7 5.97 2.31 1.48 2.02±0.67

C4 aldehydes 72.11 LM 0 7 5.97 2.31 1.48 2.02±0.67

methyl ethyl ketone 78-93-3 72.11 Exp 1 2 0 2 1.48 0.63 0.39 0.53±0.18

isobutyl alcohol 78-83-1 74.12 Exp 1 0 6 2.51 1.19 0.75 1.00±0.32

n-butyl alcohol 71-36-3 74.12 Exp 1 0 6 2.88 1.43 0.92 1.20±0.39

sec-butyl alcohol 78-92-2 74.12 Exp 1 0 6 1.36 0.76 0.51 0.64±0.17

tert-butyl alcohol 75-65-0 74.12 Exp 1 2 + 2 0.41 0.23 0.144 0.187±0.050

diethyl ether 60-29-7 74.12 Exp 1 2 0 2 3.76 1.75 1.13 1.49±0.42

gamma-butyrolactone 96-48-0 86.09 Exp 0 7 0.96 0.61 0.41 0.51±0.14

methacrylic acid 79-41-4 86.09 Exp 0 8 18.50 5.87 3.34 5.12±2.37

methyl acrylate 96-33-3 86.09 Exp 0 8 11.48 3.74 2.09 3.22±1.47

vinyl acetate 108-05-4 86.09 Exp 0 8 3.20 1.18 0.70 1.02±0.39

hydroxyl-methacrolein 40364-84-9 86.09 Exp 0 8 6.24 2.33 1.41 2.01±0.71

biacetyl 431-03-8 86.09 Exp 1 0 6 20.09 6.09 3.43 5.35±2.63

1,4-dioxane 123-91-1 88.11 Exp 0 7 2.62 1.32 0.92 1.14±0.29

ethyl acetate 141-78-6 88.11 Exp 1 2 0 3 0.63 0.37 0.25 0.31±0.08

methyl propionate 554-12-1 88.11 Exp 1 0 6 0.66 0.33 0.21 0.27±0.09

n-propyl formate 110-74-7 88.11 Exp 1 0 6 0.78 0.48 0.33 0.40±0.14

isopropyl formate 625-55-8 88.11 Exp 0 7 0.37 0.26 0.189 0.22±0.05
Table B-1 (continued)

192

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

isobutyric acid 79-31-2 88.11 Exp 0 7 1.20 0.61 0.39 0.51±0.15

butanoic acid 107-92-6 88.11 AdjP 0 7 1.82 0.90 0.56 0.75±0.23

methoxy-acetone 5878-19-3 88.11 Exp 1 0 8 2.03 0.97 0.66 0.84±0.22

1,3-butanediol 107-88-0 90.12 Exp 1 0 6 3.36 1.63 1.06 1.38±0.42

1,2-butandiol 584-03-2 90.12 AdjP 1 0 6 2.52 1.13 0.73 0.97±0.29

1,4-butanediol 110-63-4 90.12 Exp 0 7 2.72 1.29 0.82 1.08±0.36

2,3-butanediol 90.12 AdjP 1 0 6 4.38 1.85 1.07 1.53±0.60

1-methoxy-2-propanol 107-98-2 90.12 AdjP 1 2 0 2 2.44 1.24 0.86 1.08±0.28

2-ethoxy-ethanol 110-80-5 90.12 Exp 1 3 0 2 3.71 1.64 1.03 1.39±0.43

2-methoxy-1-propanol 1589-47-5 90.12 Exp 0 7 3.01 1.19 0.73 1.02±0.35

3-methoxy-1-propanol 1320-67-8 90.12 Exp 0 7 3.84 1.63 1.03 1.40±0.44

propylene carbonate 108-32-7 102.09 Exp 1 2 + 2 0.28 0.196 0.146 0.170±0.037

methyl lactate 547-64-8 104.10 Exp 1 0 6 2.67 1.05 0.58 0.86±0.36

diethylene glycol 111-46-6 106.12 AdjP 0 7 3.35 1.44 0.90 1.23±0.39

malic acid 6915-15-7 134.09 AdjP 0 8 6.94 2.36 1.29 2.00±0.89

2-methyl furan 534-22-5 82.10 Exp 1 3 0 4 8.30 3.12 1.84 2.66±1.01

3-methyl furan 930-27-8 82.10 Exp 1 3 0 4 6.90 2.75 1.66 2.34±0.82

cyclopentanone 120-92-3 84.12 Exp 1 0 8 1.15 0.70 0.46 0.58±0.18

C5 cyclic ketones 84.12 LM 0 8 1.15 0.70 0.46 0.58±0.18

cyclopentanol 96-41-3 86.13 Exp 1 0 6 1.72 0.90 0.59 0.76±0.22

alpha-methyl tetrahydrofuran 96-47-9 86.13 Exp 1 0 6 3.97 1.94 1.28 1.65±0.48

tetrahydropyran 142-68-7 86.13 Exp 1 0 6 3.22 1.73 1.14 1.45±0.41

2-methyl-3-butene-2-ol 115-18-4 86.13 Exp 1 0 8 4.91 2.01 1.29 1.74±0.55

2,2-dimethylpropanal 

(pivaldehyde)

630-19-3 86.13 Exp 1 0 8 4.89 1.88 1.23 1.66±0.54

3-methylbutanal 

(isovaleraldehyde)

590-86-3 86.13 Exp 1 0 8 4.97 1.91 1.23 1.68±0.55

pentanal (valeraldehyde) 110-62-3 86.13 Exp 1 0 8 5.08 1.99 1.29 1.75±0.56

C5 aldehydes 86.13 LM 0 8 5.08 1.99 1.29 1.75±0.56

2-pentanone 107-87-9 86.13 Exp 1 2 0 2 2.81 1.38 0.89 1.16±0.34

3-pentanone 96-22-0 86.13 Exp 1 0 6 1.24 0.63 0.40 0.52±0.18

C5 ketones 86.13 LM 0 7 2.81 1.38 0.89 1.16±0.34

methyl isopropyl ketone 563-80-4 86.13 Exp 1 0 6 1.65 0.82 0.53 0.69±0.20

2-pentanol 6032-29-7 88.15 Exp 1 0 6 1.61 0.86 0.57 0.73±0.20

3-pentanol 584-02-1 88.15 Exp 1 0 6 1.63 0.85 0.57 0.72±0.21

pentyl alcohol 71-41-0 88.15 Exp 1 0 6 2.83 1.38 0.88 1.16±0.37

isoamyl alcohol (3-methyl-1-

butanol)

123-51-3 88.15 Exp 1 0 6 3.16 1.44 0.92 1.23±0.38

2-methyl-1-butanol 137-32-6 88.15 Exp 0 7 2.40 1.17 0.75 0.98±0.30

ethyl isopropyl ether 625-54-7 88.15 Exp 0 7 3.74 1.62 1.04 1.39±0.42

methyl n-butyl ether 628-28-4 88.15 Exp 1 0 6 3.15 1.64 1.09 1.39±0.40

methyl t-butyl ether 1634-04-4 88.15 Exp 1 3 0 2 0.73 0.46 0.31 0.38±0.09

ethyl acrylate 140-88-5 100.12 Exp 0 8 7.77 2.81 1.64 2.41±0.94

methyl methacrylate 80-62-6 100.12 Exp 0 8 15.61 4.95 2.80 4.31±2.00

glutaraldehyde 111-30-8 100.12 Exp 0 8 4.31 1.70 1.14 1.51±0.46

lumped C5+ unsaturated 

carbonyl species

100.12 Exp 0 8 6.38 2.30 1.36 1.98±0.75

2,4-pentanedione 123-54-6 100.12 Exp 0 8 1.01 0.39 0.22 0.32±0.12
Table B-1 (continued)

193

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

tetrahydro-2-furanmethanol 

(tetrahydrofurfuryl alcohol)

97-99-4 102.13 Exp 0 7 3.31 1.42 0.89 1.21±0.38

ethyl propionate 105-37-3 102.13 Exp 1 0 6 0.77 0.45 0.30 0.37±0.11

isopropyl acetate 108-21-4 102.13 Exp 1 2 0 2 1.07 0.59 0.40 0.50±0.12

methyl butyrate 623-42-7 102.13 Exp 1 0 6 1.09 0.57 0.36 0.47±0.14

methyl isobutyrate 547-63-7 102.13 Exp 1 2 0 2 0.61 0.36 0.23 0.30±0.09

n-butyl formate 592-84-7 102.13 Exp 1 0 6 0.83 0.52 0.35 0.44±0.14

propyl acetate 109-60-4 102.13 Exp 1 0 6 0.78 0.49 0.34 0.41±0.12

3-methyl butanoic acid 503-74-2 102.13 AdjP 0 7 4.23 1.66 0.96 1.39±0.53

2,2-dimethoxy-propane 77-76-9 104.15 Exp 0 7 0.48 0.31 0.21 0.26±0.06

1-ethoxy-2-propanol 1569-02-4 104.15 Exp 0 7 3.09 1.52 0.97 1.27±0.37

2-propoxy-ethanol 2807-30-9 104.15 AdjP 0 7 3.30 1.53 0.99 1.30±0.38

3-ethoxy-1-propanol 111-35-3 104.15 Exp 1 0 6 4.09 1.76 1.10 1.50±0.47

3-methoxy-1-butanol 2517-43-3 104.15 Exp 1 0 6 3.87 1.54 0.95 1.32±0.45

2-methoxyethyl acetate 110-49-6 118.13 Exp 0 7 1.15 0.68 0.48 0.58±0.13

ethyl lactate 97-64-3 118.13 Exp 1 0 6 2.48 1.05 0.61 0.87±0.33

methyl isopropyl carbonate 51729-83-0 118.13 Exp 1 2 0 2 0.62 0.35 0.24 0.30±0.07

2-(2-methoxyethoxy) ethanol 111-77-3 120.15 AdjP 0 7 2.66 1.29 0.87 1.11±0.30

pentaerythritol 115-77-5 136.15 AdjP 0 7 2.17 1.01 0.65 0.86±0.28

phenol 108-95-2 94.11 LM 0 8 2.76 0.173 -0.85 -0.22±0.76

2-ethyl furan 3208-16-0 96.13 LM 0 8 7.09 2.67 1.57 2.27±0.86

2,5-dimethyl furan 625-86-5 96.13 Exp 1 3 0 4 7.88 2.89 1.69 2.47±0.96

cyclohexanone 108-94-1 98.14 Exp 1 2 0 2 1.35 0.79 0.48 0.63±0.22

C6 cyclic ketones 98.14 LM 0 7 1.35 0.79 0.48 0.63±0.22

mesityl oxide (2-methyl-2-

penten-4-one)

141-79-7 98.14 LM 0 8 6.51 2.34 1.39 2.02±0.77

cyclohexanol 108-93-0 100.16 AdjP 1 0 6 1.95 1.07 0.68 0.88±0.27

hexanal 66-25-1 100.16 Exp 1 0 8 4.35 1.71 1.10 1.49±0.48

C6 aldehydes 100.16 LM 0 8 4.35 1.71 1.10 1.49±0.48

4-methyl-2-pentanone 108-10-1 100.16 Exp 1 2 0 3 3.88 1.68 1.08 1.44±0.43

methyl n-butyl ketone 591-78-6 100.16 Exp 1 0 8 3.14 1.54 0.99 1.30±0.39

methyl tert-butyl ketone 75-97-8 100.16 Exp 1 0 8 0.65 0.34 0.21 0.28±0.08

C6 ketones 100.16 LM 0 8 3.14 1.54 0.99 1.30±0.39

1-hexanol 111-27-3 102.17 AdjP 1 0 6 2.69 1.35 0.86 1.13±0.36

2-hexanol 626-93-7 102.17 AdjP 1 0 6 2.08 1.21 0.78 1.00±0.30

4-methyl-2-pentanol (methyl 

isobutyl carbinol)

108-11-2 102.17 AdjP 0 7 2.64 1.39 0.90 1.16±0.33

di-n-propyl ether 111-43-3 102.17 Exp 1 0 6 3.08 1.60 1.08 1.36±0.36

ethyl n-butyl ether 628-81-9 102.17 Exp 1 0 6 3.48 1.66 1.07 1.40±0.41

ethyl tert-butyl ether 637-92-3 102.17 Exp 1 0 6 2.01 0.99 0.63 0.83±0.23

methyl tert-amyl ether (TAME) 994-05-8 102.17 Exp 1 0 6 1.69 0.94 0.61 0.78±0.21

diisopropyl ether 108-20-3 102.17 Exp 0 7 3.52 1.45 0.89 1.23±0.41

ethyl methacrylate 97-63-2 114.14 Exp 0 8 12.47 4.02 2.27 3.49±1.59

ethyl butyrate 105-54-4 116.16 Exp 1 0 6 1.17 0.64 0.41 0.53±0.15

isobutyl acetate 110-19-0 116.16 Exp 0 7 0.62 0.43 0.30 0.36±0.08

methyl pivalate 598-98-1 116.16 Exp 1 2 0 2 0.35 0.22 0.133 0.172±0.054

n-butyl acetate 123-86-4 116.16 Exp 1 2 0,+ 2 0.83 0.54 0.35 0.43±0.13

n-propyl propionate 106-36-5 116.16 Exp 1 0 6 0.84 0.52 0.33 0.42±0.14

sec-butyl acetate 105-46-4 116.16 Exp 1 0 6 1.32 0.79 0.54 0.67±0.17
Table B-1 (continued)

194

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

tert-butyl acetate 540-88-5 116.16 Exp 1 3 0 2 0.180 0.102 0.062 0.082±0.024

diacetone alcohol 123-42-2 116.16 Exp 0 8 0.60 0.32 0.20 0.26±0.09

methyl pentanoate; methyl 

valerate

624-24-8 116.16 Exp 0 7 1.05 0.59 0.37 0.48±0.15

1,2-dihydroxyhexane 6920-22-5 118.17 AdjP 0 7 2.55 1.21 0.76 1.01±0.33

2-methyl-2,4-pentanediol 107-41-5 118.17 Exp 1 0 6 1.45 0.69 0.45 0.59±0.17

ethylene glycol diethyl ether; 

1,2-diethoxyethane

629-14-1 118.17 Exp 0 7 2.95 1.44 0.93 1.21±0.35

acetal (1,1-diethoxyethane) 105-57-7 118.17 Exp 0 7 3.58 1.53 0.99 1.32±0.40

1-propoxy-2-propanol 

(propylene glycol n-propyl 

ether)

1569-01-3 118.17 AdjP 0 7 2.68 1.36 0.92 1.16±0.31

2-butoxy-ethanol 111-76-2 118.17 Exp 1 2 0 2 2.90 1.30 0.79 1.08±0.35

3 methoxy-3 methyl-butanol 56539-66-3 118.17 Exp 1 2 0 2 2.88 1.32 0.84 1.12±0.34

n-propoxy-propanol 30136-13-1 118.17 Exp 0 7 3.77 1.69 1.07 1.43±0.44

hydroxypropyl acrylate 2918-23-2 130.14 Exp 0 8 4.90 1.94 1.18 1.65±0.57

1-methoxy-2-propyl acetate 108-65-6 132.16 Exp 1 2 0,+ 2 1.70 0.86 0.58 0.73±0.19

2-ethoxyethyl acetate 111-15-9 132.16 Exp 0 7 1.84 0.92 0.60 0.77±0.21

2-methyoxy-1-propyl acetate 70657-70-4 132.16 Exp 0 7 1.12 0.60 0.42 0.52±0.12

methoxypropanol acetate 84540-57-8 132.16 Exp 0 7 1.86 0.98 0.64 0.82±0.24

2-(2-ethoxyethoxy) ethanol 111-90-0 134.17 Exp 1 3 0 2 3.26 1.50 0.94 1.26±0.39

dipropylene glycol isomer (1-

[2-hydroxypropyl]-2-propanol)

110-98-5 134.17 AdjP 0 7 2.31 1.18 0.79 1.00±0.28

dimethyl succinate 106-65-0 146.14 Exp 1 2 0 2 0.23 0.142 0.089 0.114±0.033

ethylene glycol diacetate 111-55-7 146.14 Exp 0 7 0.66 0.40 0.27 0.33±0.12

adipic acid (hexanedioic acid) 124-04-9 146.14 AdjP 0 8 3.08 1.46 0.93 1.23±0.40

triethylene glycol 112-27-6 150.17 Exp 0 7 3.25 1.51 0.94 1.26±0.40

benzaldehyde 100-52-7 106.12 Exp 1 3 0 2 -0.67 -0.69 -1.05 -0.90±0.29

C7 alkyl phenols 1319-77-3 108.14 LM 0 5 2.40 0.150 -0.74 -.187±0.661

m-cresol 108-39-4 108.14 LM 4 -,0 5 2.40 0.150 -0.74 -.187±0.661

p-cresol 106-44-5 108.14 LM 4 0? 5 2.40 0.150 -0.74 -.187±0.661

o-cresol 95-48-7 108.14 Exp 1 4 ? 5 2.40 0.150 -0.74 -.187±0.661

benzyl alcohol 100-51-6 108.14 Exp 1 2 0 4 5.11 1.73 0.82 1.40±0.69

methoxybenzene; anisole 100-66-3 108.14 Exp 1 0 8 6.66 2.19 1.00 1.76±0.91

C7 cyclic ketones 112.17 LM 0 8 1.18 0.69 0.42 0.55±0.19

heptanal 111-71-7 114.19 Exp 1 0 8 3.69 1.45 0.92 1.26±0.41

C7 aldehydes 114.19 LM 0 8 3.69 1.45 0.92 1.26±0.41

2-methyl-hexanal 925-54-2 114.19 Exp 0 8 3.54 1.43 0.91 1.24±0.40

2-heptanone 110-43-0 114.19 Exp 1 3 ? 4 2.36 1.23 0.75 1.00±0.33

2-methyl-3-hexanone 7379-12-6 114.19 Exp 0 8 1.53 0.83 0.52 0.68±0.23

di-isopropyl ketone 565-80-0 114.19 Exp 1 0 8 1.31 0.72 0.45 0.58±0.21

C7 ketones 114.19 LM 0 8 2.36 1.23 0.75 1.00±0.33

5-methyl-2-hexanone 110-12-3 114.19 AdjP 1 0 8 2.41 1.26 0.82 1.05±0.32

3-methyl-2-hexanone 2550-21-2 114.19 Exp 0 8 2.55 1.32 0.83 1.09±0.34

1-heptanol 111-70-6 116.20 Exp 1 0 6 1.84 0.97 0.59 0.79±0.26

dimethylpentanol (2,3-

dimethyl-1-pentanol)

10143-23-4 116.20 Exp 0 7 2.23 1.09 0.67 0.90±0.29

4,4-diethyl-3-oxahexane 919-94-8 116.20 Exp 0 7 1.95 0.97 0.60 0.80±0.24

n-butyl acrylate 141-32-2 128.17 Exp 0 8 5.02 1.90 1.09 1.60±0.61
Table B-1 (continued)

195

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

isobutyl acrylate 106-63-8 128.17 AdjP 0 8 4.72 1.80 1.02 1.51±0.59

butyl propionate 590-01-2 130.18 Exp 0 7 0.84 0.52 0.32 0.42±0.14

amyl acetate (n-pentyl acetate) 628-63-7 130.18 AdjP 0 7 0.84 0.55 0.32 0.42±0.14

n-propyl butyrate 105-66-8 130.18 Exp 1 0 6 1.05 0.61 0.38 0.49±0.16

isoamyl acetate (3-methyl-butyl 

acetate)

123-92-2 130.18 Exp 0 7 1.09 0.65 0.40 0.52±0.17

2-methyl-1-butyl acetate 624-41-9 130.18 Exp 0 7 1.08 0.67 0.43 0.55±0.15

methyl hexanoate 106-70-7 130.18 Exp 0 7 1.02 0.60 0.35 0.47±0.16

1-tert-butoxy-2-propanol 57018-52-7 132.20 AdjP 0 7 1.61 0.85 0.54 0.70±0.21

2-tert-butoxy-1-propanol 94023-15-1 132.20 Exp 0 7 1.81 0.72 0.41 0.60±0.22

n-butoxy-2-propanol (propylene 

glycol n-butyl ether)

5131-66-8 132.20 Exp 0 7 2.72 1.33 0.85 1.12±0.34

ethyl 3-ethoxy propionate 763-69-9 146.18 AdjP 0 7 3.58 1.45 0.85 1.21±0.43

diisopropyl carbonate 6482-34-4 146.18 Exp 0 7 0.98 0.51 0.32 0.42±0.12

2-(2-propoxyethoxy) ethanol 6881-94-3 148.20 Exp 0 7 2.85 1.37 0.86 1.14±0.35

dipropylene glycol methyl 

ether: 1-methoxy-2-(2-

hydroxypropoxy)-propane

148.20 AdjP 0 7 1.98 0.99 0.66 0.84±0.23

dipropylene glycol methyl 

ether: 2-(2-methoxypropoxy)-1-

propanol

13588-28-8 148.20 AdjP 0 7 2.58 1.16 0.73 0.98±0.30

1,2-propylene glycol diacetate 623-84-7 160.17 Exp 0 7 0.61 0.38 0.26 0.32±0.08

dimethyl glutarate 1119-40-0 160.17 AdjP 1 2 0 2 0.42 0.25 0.124 0.182±0.073

2-[2-(2-methoxyethoxy) 

ethoxy] ethanol

112-35-6 164.20 Exp 0 7 2.58 1.27 0.80 1.06±0.32

tolualdehyde 120.15 LM 0 7 -0.59 -0.61 -0.93 -0.79±0.26

4-vinyl phenol 2628-17-3 120.15 LM 0 11 1.50 0.185 -0.42 -.092±0.434

2,4-dimethyl phenol 105-67-9 122.16 LM 0 8 2.12 0.133 -0.66 -.166±0.585

2,5-dimethyl phenol 122.16 LM 0 8 2.12 0.133 -0.66 -.166±0.585

3,4-dimethyl phenol 95-65-8 122.16 LM 0 8 2.12 0.133 -0.66 -.166±0.585

2,3-dimethyl phenol 526-75-0 122.16 LM 0 8 2.12 0.133 -0.66 -.166±0.585

2,6-dimethyl phenol 576-26-1 122.16 LM 0 8 2.12 0.133 -0.66 -.166±0.585

C8 alkyl phenols 122.16 LM 0 8 2.12 0.133 -0.66 -.166±0.585

β-phenethyl alcohol (2-phenyl 

ethyl alcohol)

98-85-1 122.16 LM - 11 4.53 1.53 0.73 1.24±0.61

C8 cyclic ketones 126.20 LM 0 8 1.05 0.61 0.37 0.49±0.17

2-butyl tetrahydrofuran 1004-29-1 128.21 Exp 0 7 2.13 1.06 0.62 0.85±0.31

octanal 124-13-0 128.21 Exp 0 8 3.16 1.24 0.77 1.07±0.36

C8 aldehydes 128.21 LM 0 8 3.16 1.24 0.77 1.07±0.36

2-octanone 111-13-7 128.21 Exp 1 0 8 1.40 0.80 0.44 0.61±0.23

C8 ketones 128.21 LM 0 8 1.40 0.80 0.44 0.61±0.23

1-octanol 111-87-5 130.23 Exp 1 2 + 2 1.43 0.79 0.45 0.62±0.22

2-ethyl-1-hexanol 104-76-7 130.23 Exp 0 7 2.00 0.99 0.58 0.80±0.27

2-octanol 4128-31-8 130.23 Exp 1 2 + 2 1.97 1.04 0.63 0.84±0.28

3-octanol 20296-29-1 130.23 Exp 1 2 + 2 2.28 1.16 0.72 0.95±0.31

4-octanol 589-62-8 130.23 AdjP 1 0 6 2.23 1.18 0.71 0.95±0.32

5-methyl-1-heptanol 7212-53-5 130.23 AdjP 0 7 1.79 0.91 0.52 0.72±0.26

di-isobutyl ether 628-55-7 130.23 Exp 1 0 6 1.20 0.67 0.41 0.54±0.17

di-n-butyl ether 142-96-1 130.23 Exp 1 0 6 2.84 1.40 0.88 1.16±0.37
Table B-1 (continued)

196

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

2-phenoxyethanol; ethylene 

glycol phenyl ether

122-99-6 138.16 Exp 0 8 4.49 1.62 0.84 1.33±0.58

butyl methacrylate 97-88-1 142.20 Exp 0 8 8.70 2.85 1.58 2.45±1.12

isobutyl methacrylate 97-86-9 142.20 Exp 0 8 8.62 2.81 1.55 2.41±1.11

hexyl acetates 144.21 LM 0 7 0.80 0.51 0.28 0.38±0.14

2,3-dimethylbutyl acetate 144.21 Exp 0 7 0.75 0.48 0.28 0.37±0.12

2-methylpentyl acetate 144.21 Exp 0 7 0.98 0.59 0.33 0.45±0.17

3-methylpentyl acetate 144.21 AdjP 0 7 1.07 0.64 0.38 0.50±0.17

4-methylpentyl acetate 144.21 Exp 0 7 0.82 0.50 0.28 0.38±0.14

isobutyl isobutyrate 97-85-8 144.21 Exp 0 7 0.60 0.39 0.23 0.30±0.10

n-butyl butyrate 109-21-7 144.21 Exp 1 0 6 1.08 0.62 0.36 0.49±0.17

n-hexyl acetate 142-92-7 144.21 AdjP 0 7 0.69 0.47 0.24 0.34±0.14

methyl amyl acetate (4-methyl2-pentanol acetate)108-84-9 144.21 Exp 0 7 1.35 0.72 0.40 0.56±0.19

n-pentyl propionate 624-54-4 144.21 AdjP 0 7 0.71 0.46 0.24 0.34±0.13

2-ethyl hexanoic acid 149-57-5 144.21 Exp 0 7 3.32 1.42 0.79 1.15±0.43

methyl heptanoate 106-73-0 144.21 Exp 0 7 0.82 0.51 0.27 0.38±0.15

2-ethyl-1,3-hexanediol 94-96-2 146.23 AdjP 0 7 2.05 1.03 0.64 0.85±0.28

2-n-hexyloxyethanol 112-25-4 146.23 AdjP 0 7 2.09 1.05 0.63 0.85±0.28

2,2,4-trimethyl-1,3-pentanediol 144-19-4 146.23 Exp 0 7 1.54 0.81 0.51 0.67±0.21

phthalic anhydride 85-44-9 148.12 Exp 0 8 2.58 0.92 0.40 0.71±0.37

methylparaben (4-

Hydroxybenzoic acid, methyl 

ester)

99-76-3 152.15 LM 0 11 1.71 0.107 -0.53 -.133±0.470

2-butoxyethyl acetate 112-07-2 160.21 Exp 0 7 1.62 0.85 0.53 0.70±0.21

2-methoxy-1-(2-methoxy-1-

methylethoxy)-propane; 

dipropylene glycol dimethyl 

ether

89399-28-0 162.23 AdjP 0 7 2.02 0.98 0.64 0.83±0.23

2-(2-butoxyethoxy)-ethanol 112-34-5 162.23 Exp 2 0 7 2.39 1.15 0.69 0.94±0.32

dipropylene glycol ethyl ether 15764-24-6 162.23 Exp 0 7 2.72 1.24 0.75 1.03±0.34

dimethyl adipate 627-93-0 174.19 AdjP 1 0 6 1.80 0.84 0.48 0.68±0.25

2-(2-ethoxyethoxy) ethyl 

acetate

112-15-2 176.21 AdjP 0 7 1.48 0.78 0.50 0.64±0.18

2-[2-(2-ethoxyethoxy) ethoxy] 

ethanol

112-50-5 178.23 Exp 0 7 2.46 1.21 0.75 1.00±0.32

tetraethylene glycol 112-60-7 194.23 Exp 0 7 2.51 1.20 0.75 1.00±0.32

cinnamic aldehyde 104-55-2 132.16 LM 0 10 4.84 1.74 1.03 1.50±0.57

Cinnamic alcohol 104-54-1 134.18 LM -1 10 0.89 0.136 -0.28 -.065±0.265

2,3,5-trimethyl phenol 697-82-5 136.19 LM 0 8 1.90 0.119 -0.59 -.149±0.525

2,3,6-trimethyl phenol 2416-94-6 136.19 LM 0 8 1.90 0.119 -0.59 -.149±0.525

C9 alkyl phenols 136.19 LM 0 8 1.90 0.119 -0.59 -.149±0.525

isophorone (3,5,5-trimethyl-2-

cyclohexenone)

78-59-1 138.21 LM 0 8 4.63 1.66 0.99 1.44±0.54

C9 cyclic ketones 140.22 LM 0 8 0.94 0.55 0.33 0.44±0.15

2-propyl cyclohexanone 94-65-5 140.22 AdjP 0 8 1.54 0.85 0.46 0.65±0.27

4-propyl cyclohexanone 40649-36-3 140.22 Exp 0 8 1.85 0.97 0.56 0.77±0.29

1-nonene-4-one 61168-10-3 140.22 Exp 0 8 3.14 1.28 0.74 1.06±0.39

trimethyl cyclohexanol 1321-60-4 142.24 AdjP 0 7 1.86 1.01 0.56 0.78±0.29
Table B-1 (continued)

197

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

2-nonanone 821-55-6 142.24 Exp 1 0 8 1.08 0.64 0.32 0.47±0.20

di-isobutyl ketone (2,6-

dimethyl-4-heptanone)

108-83-8 142.24 Exp 1 0 8 2.68 1.20 0.72 0.99±0.33

C9 ketones 142.24 LM 0 8 1.08 0.64 0.32 0.47±0.20

dimethyl heptanol (2,6-

dimethyl-2-heptanol)

13254-34-7 144.25 Exp 0 7 0.94 0.53 0.28 0.40±0.16

2,6-dimethyl-4-heptanol 108-82-7 144.25 AdjP 0 7 2.09 1.06 0.62 0.85±0.30

1-phenoxy-2-propanol 770-35-4 152.19 LM 0 8 1.60 0.65 0.28 0.49±0.24

2,4-dimethylpentyl acetate 158.24 Exp 0 7 0.92 0.53 0.26 0.39±0.16

2-methylhexyl acetate 158.24 AdjP 0 7 0.69 0.45 0.21 0.31±0.15

3-ethylpentyl acetate 158.24 Exp 0 7 1.10 0.65 0.36 0.50±0.19

3-methylhexyl acetate 158.24 Exp 0 7 0.89 0.55 0.28 0.40±0.17

4-methylhexyl acetate 158.24 Exp 0 7 0.82 0.50 0.26 0.37±0.15

5-methylhexyl acetate 158.24 AdjP 0 7 0.59 0.39 0.167 0.27±0.14

isoamyl isobutyrate 2050-01-3 158.24 Exp 0 7 0.82 0.48 0.26 0.36±0.14

n-heptyl acetate 112-06-1 158.24 Exp 0 7 0.65 0.44 0.20 0.30±0.14

methyl octanoate 111-11-5 158.24 Exp 0 7 0.69 0.44 0.20 0.31±0.14

1-(butoxyethoxy)-2-propanol 124-16-3 176.25 AdjP 0 7 1.93 1.00 0.63 0.83±0.25

dipropylene glycol n-propyl 

ether isomer #1

176.25 AdjP 0 7 2.00 1.01 0.64 0.84±0.25

dipropylene glycol methyl ether 

acetate isomer #1

190.24 AdjP 0 7 1.38 0.72 0.45 0.59±0.17

dipropylene glycol methyl ether 

acetate isomer #2

190.24 AdjP 0 7 1.52 0.77 0.48 0.63±0.19

dipropylene glycol methyl ether 

acetate isomers

88917-22-0 190.24 LM 0 7 1.45 0.74 0.46 0.61±0.18

2-[2-(2-propoxyethoxy) ethoxy]

ethanol

23305-64-8 192.25 Exp 0 7 2.17 1.08 0.66 0.88±0.29

tripropylene glycol 24800-44-0 192.25 Exp 0 7 2.18 1.10 0.68 0.90±0.29

2,5,8,11-tetraoxatridecan-13-ol 23783-42-8 208.25 Exp 0 7 1.97 1.00 0.62 0.82±0.27

glyceryl triacetate 102-76-1 218.20 Exp 0 7 0.55 0.34 0.20 0.27±0.09

anethol (p-propenyl-anisole) 104-46-1 148.20 LM 0 11 0.80 0.123 -0.25 -.059±0.239

C10 alkyl phenols 150.22 LM 0 8 1.73 0.108 -0.53 -.135±0.476

camphor 76-22-2 152.23 Exp 0 8 0.49 0.31 0.129 0.21±0.12

α-terpineol 98-55-5 154.25 Exp 0 8 4.63 1.63 0.89 1.38±0.64

citronellol (3,7-dimethy-6-

octen-1-ol)

106-22-9 154.25 Exp 0 8 5.79 1.99 1.09 1.70±0.79

hydroxycitronella 107-75-5 154.25 Exp 0 8 2.61 1.03 0.64 0.89±0.30

C10 cyclic ketones 154.25 LM 0 8 0.86 0.50 0.30 0.40±0.14

menthol 89-78-1 156.27 Exp 0 7 1.43 0.76 0.44 0.60±0.22

linalool 78-70-6 156.27 Exp 0 8 5.43 1.91 1.07 1.63±0.75

2-decanone 693-54-9 156.27 AdjP 1 0 8 0.90 0.55 0.25 0.38±0.19

C10 ketones 156.27 LM 0 8 0.90 0.55 0.25 0.38±0.19

8-methyl-1-nonanol (isodecyl 

alcohol)

25339-17-7 158.28 Exp 0 7 1.06 0.58 0.30 0.44±0.18

1-decanol 112-30-1 158.28 Exp 0 7 1.06 0.59 0.31 0.45±0.18

3,7-dimethyl-1-octanol 106-21-8 158.28 Exp 0 7 1.20 0.63 0.34 0.49±0.19

di-n-pentyl ether 693-65-2 158.28 AdjP 1 0 6 2.15 1.16 0.71 0.94±0.31

1,2-diacetyl benzene 704-00-7 162.19 Exp 1 0 8 2.25 0.79 0.33 0.60±0.33
Table B-1 (continued)

198

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

2,4-dimethylhexyl acetate 172.26 AdjP 0 7 0.76 0.47 0.21 0.33±0.16

2-ethyl-hexyl acetate 103-09-3 172.26 AdjP 0 7 0.66 0.43 0.175 0.28±0.15

3,4-dimethyl-hexyl acetate 172.26 AdjP 0 7 0.87 0.55 0.28 0.40±0.17

3,5-dimethyl-hexyl acetate 172.26 Exp 0 7 0.99 0.58 0.28 0.41±0.18

3-ethyl-hexyl acetate 172.26 Exp 0 7 0.91 0.55 0.28 0.40±0.17

3-methyl-heptyl acetate 172.26 Exp 0 7 0.67 0.44 0.194 0.30±0.15

4,5-dimethyl-hexyl acetate 172.26 AdjP 0 7 0.68 0.43 0.20 0.30±0.14

4-methyl-heptyl acetate 172.26 Exp 0 7 0.66 0.42 0.187 0.29±0.14

5-methyl-heptyl acetate 172.26 AdjP 0 7 0.61 0.41 0.163 0.27±0.15

n-octyl acetate 112-14-1 172.26 Exp 0 7 0.57 0.39 0.163 0.26±0.14

geraniol 106-24-1 172.26 Exp 0 8 5.12 1.84 1.04 1.58±0.71

methyl nonanoate 1731-84-6 172.26 Exp 0 7 0.59 0.39 0.161 0.26±0.14

2-(2-ethylhexyloxy) ethanol 1559-35-9 174.28 AdjP 0 7 1.55 0.83 0.44 0.63±0.25

propylparaben 94-13-3 180.20 LM 0 11 1.44 0.090 -0.45 -.112±0.397

2-(2-hexyloxyethoxy) ethanol 112-59-4 190.28 AdjP 0 7 1.84 0.97 0.57 0.77±0.26

glycol ether DPnB (dipropylene 

glycol n-butyl ether) (1-[2-

butoxy-1-methylethoxy]-2-

propanol)

29911-28-2 190.28 AdjP 0 7 1.83 0.93 0.57 0.76±0.24

2-(2-butoxyethoxy) ethyl 

acetate

124-17-4 204.26 Exp 0 7 1.38 0.73 0.44 0.59±0.20

2-[2-(2-butoxyethoxy) ethoxy] 

ethanol

143-22-6 206.28 Exp 0 7 1.96 0.98 0.60 0.80±0.27

tripropylene glycol 

monomethyl ether

25498-49-1 206.28 Exp 0 7 1.92 0.96 0.59 0.78±0.26

C11 alkyl phenols 164.24 LM 0 8 1.58 0.099 -0.49 -.123±0.435

2-ethyl-hexyl acrylate 103-11-7 184.28 Exp 0 8 2.52 0.99 0.50 0.79±0.33

2,3,5-trimethyl-hexyl acetate 186.29 AdjP 0 7 0.85 0.51 0.24 0.37±0.16

2,3-dimethyl-heptyl acetate 186.29 Exp 0 7 0.71 0.46 0.21 0.32±0.15

2,4-dimethyl-heptyl acetate 186.29 AdjP 0 7 0.68 0.42 0.164 0.28±0.16

2,5-dimethyl-heptyl acetate 186.29 Exp 0 7 0.78 0.49 0.23 0.35±0.16

2-methyloctyl acetate 186.29 AdjP 0 7 0.52 0.35 0.118 0.22±0.15

3,5-dimethyl-heptyl acetate 186.29 AdjP 0 7 0.81 0.50 0.21 0.34±0.18

3,6-dimethyl-heptyl acetate 186.29 Exp 0 7 0.78 0.48 0.21 0.33±0.17

3-ethyl-heptyl acetate 186.29 Exp 0 7 0.63 0.41 0.172 0.28±0.15

4,5-dimethyl-heptyl acetate 186.29 AdjP 0 7 0.69 0.44 0.196 0.30±0.15

4,6-dimethyl-heptyl acetate 186.29 Exp 0 7 0.78 0.47 0.21 0.33±0.16

4-methyloctyl acetate 186.29 Exp 0 7 0.61 0.40 0.167 0.27±0.14

5-methyloctyl acetate 186.29 AdjP 0 7 0.56 0.38 0.134 0.24±0.15

n-nonyl acetate 143-13-5 186.29 Exp 0 7 0.52 0.36 0.139 0.23±0.13

methyl decanoate 110-42-9 186.29 Exp 0 7 0.53 0.35 0.136 0.23±0.13

C12 alkyl phenols 178.27 LM 0 8 1.46 0.091 -0.45 -.114±0.401

2,6,8-trimethyl-4-nonanone 

(isobutyl heptyl ketone)

123-18-2 184.32 Exp 0 8 1.66 0.81 0.44 0.63±0.24

trimethylnonanolthreoerythro 

(2,6,8-trimethyl-4-nonanol)

123-17-1 186.33 AdjP 0 7 1.33 0.70 0.36 0.53±0.22

3,6-dimethyl-octyl acetate 200.32 Exp 0 7 0.79 0.48 0.22 0.34±0.17

3-isopropyl-heptyl acetate 200.32 AdjP 0 7 0.54 0.37 0.134 0.23±0.15

4,6-dimethyl-octyl acetate 200.32 Exp 0 7 0.76 0.46 0.20 0.32±0.16
Table B-1 (continued)

199

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

methyl undecanoate 1731-86-8 200.32 Exp 0 7 0.50 0.33 0.123 0.21±0.13

1-hydroxy-2,2,4-

trimethylpentyl-3-isobutyrate

18491-15-1 216.32 Exp 0 7 0.89 0.43 0.23 0.34±0.13

3-hydroxy-2,2,4-

trimethylpentyl-1-isobutyrate

77-68-9 216.32 AdjP 0 7 0.77 0.43 0.22 0.32±0.13

2,2,4-trimethyl-1,3-pentanediol 

monoisobutyrate and isomers 

(texanol®)

25265-77-4 216.32 LM 1 2 0 2 0.81 0.43 0.23 0.33±0.13

substituted C7 ester (C12) 216.32 LM 0 7 0.81 0.43 0.23 0.33±0.13

substituted C9 ester (C12) 216.32 LM 0 7 0.81 0.43 0.23 0.33±0.13

diethylene glycol mono(2-

ethylhexyl) ether

1559-36-0 218.33 Exp 0 7 1.56 0.82 0.47 0.64±0.24

diethyl phthalate 84-66-2 222.24 Exp 0 8 1.62 0.60 0.26 0.46±0.23

dimethyl sebacate 106-79-6 230.30 Exp 0 7 0.43 0.28 0.102 0.178±0.106

diisopropyl adipate 6938-94-9 230.30 Exp 0 7 1.28 0.55 0.25 0.41±0.19

3,6,9,12-tetraoxa-hexadecan-1-

ol

1559-34-8 250.33 AdjP 0 7 1.72 0.88 0.53 0.71±0.24

triethyl citrate 77-93-0 276.28 Exp 0 8 0.70 0.33 0.171 0.25±0.10

3,5,7-trimethyl-octyl acetate 214.34 AdjP 0 7 0.66 0.41 0.157 0.27±0.16

3-ethyl-6-methyl-octyl acetate 214.34 AdjP 0 7 0.63 0.41 0.158 0.27±0.16

4,7-dimethyl-nonyl acetate 214.34 AdjP 0 7 0.50 0.34 0.109 0.21±0.14

methyl dodecanoate (methyl 

laurate)

111-82-0 214.34 Exp 0 7 0.47 0.31 0.114 0.199±0.124

tripropylene glycol n-butyl 

ether

55934-93-5 248.36 Exp 0 7 1.64 0.80 0.47 0.64±0.23

amyl cinnamal 122-40-7 202.29 LM 0 10 3.16 1.14 0.68 0.98±0.37

isobornyl methacrylate 7534-94-3 222.32 LM + 10 5.51 1.80 0.99 1.54±0.71

2,3,5,7-tetramethyl-octyl 

acetate

228.37 Exp 0 7 0.62 0.39 0.161 0.26±0.15

3,5,7-trimethyl-nonyl acetate 228.37 AdjP 0 7 0.62 0.38 0.149 0.25±0.15

3,6,8-trimethyl-nonyl acetate 228.37 AdjP 0 7 0.59 0.37 0.130 0.24±0.15

methyl tridecanoate 1731-88-0 228.37 Exp 0 7 0.45 0.30 0.109 0.190±0.119

hexyl cinnamal 101-86-0 216.32 LM 0 10 2.96 1.06 0.63 0.92±0.35

2,6-di-tert-butyl-p-cresol 128-37-0 220.35 LM 0 10 1.18 0.074 -0.36 -.092±0.324

2-ethyl-hexyl benzoate 5444-75-7 234.33 Exp 0 10 0.98 0.46 0.20 0.33±0.16

2,4,6,8-tetramethyl-nonyl 

acetate

242.40 AdjP 0 7 0.51 0.32 0.107 0.20±0.14

3-ethyl-6,7-dimethyl-nonyl 

acetate

242.40 AdjP 0 7 0.61 0.40 0.156 0.26±0.15

4,7,9-trimethyl-decyl acetate 242.40 AdjP 0 7 0.42 0.28 0.072 0.160±0.134

methyl myristate (methyl 

tetradecanoate)

124-10-7 242.40 Exp 0 7 0.43 0.29 0.106 0.184±0.115

methyl cis-9-pentadecenoate 254.41 Exp 0 8 1.80 0.79 0.46 0.65±0.25

methyl pentadecanoate 7132-64-1 256.42 Exp 0 7 0.47 0.30 0.125 0.20±0.12

2,3,5,6,8-pentamethyl-nonyl 

acetate

256.42 Exp 0 7 0.65 0.42 0.183 0.29±0.15

3,5,7,9-tetramethyl-decyl 

acetate

256.42 AdjP 0 7 0.48 0.31 0.098 0.190±0.143

5-ethyl-3,6,8-trimethyl-nonyl 

acetate

256.42 AdjP 0 7 0.77 0.46 0.20 0.32±0.16
Table B-1 (continued)

200

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

dibutyl phthalate 84-74-2 278.34 Exp 0 8 1.25 0.49 0.23 0.38±0.18

2,2,4-trimethyl-1,3-pentanediol 

diisobutyrate

6846-50-0 286.41 Exp 0 7 0.38 0.24 0.092 0.157±0.091

methyl cis-9-hexadecenoate 

(methyl palmitoleate)

1120-25-8 268.43 LM 0 8 1.70 0.75 0.44 0.62±0.23

methyl hexadecanoate (methyl 

palmitate)

112-39-0 270.45 LM 0 7 0.44 0.29 0.118 0.192±0.111

Methyl cis-9-heptadecenoate 282.46 LM 0 8 1.62 0.71 0.42 0.58±0.22

methyl heptadecanoate (methyl 

margarate)

1731-92-6 284.48 LM 0 7 0.42 0.27 0.113 0.182±0.105

methyl linolenate (methyl 

cis,cis,cis-9,12,15-

octadecatrienoate)

301-00-8 292.46 Exp 0 8 2.32 0.95 0.57 0.80±0.29

methyl linoelate (methyl cis,cis9,12-octadecadienoate)112-63-0 294.47 Exp 0 8 1.84 0.78 0.47 0.65±0.24

methyl cis-9-octadecenoate 

(methyl oleate)

112-62-9 296.49 LM 0 8 1.54 0.68 0.40 0.56±0.21

methyl octadecanoate (methyl 

stearate)

112-61-8 298.50 LM 0 7 0.40 0.26 0.107 0.174±0.100

Other Organic Compounds

methylamine 74-89-5 31.06 Exp 1 + 13 a,n 7.70 4.24 2.72 3.51±1.06

methyl chloride 74-87-3 50.49 Exp 1 0 10 0.038 0.022 .0140 .0179±.0050

methyl nitrite 624-91-9 61.04 Exp 1 0 6 10.84 4.41 3.89 4.49±1.13

nitromethane 75-52-5 61.04 Exp 1 0 8 0.068 0.042 0.031 0.037±0.007

carbon disulfide 75-15-0 76.14 Exp 1 2 0 2 0.25 0.161 0.121 0.141±0.025

dichloromethane 75-09-2 84.93 Exp 1 0 10 0.041 0.029 0.021 0.024±0.006

methyl bromide 74-83-9 94.94 Exp 1 0 10 .0187 .0106 .0068 .0088±.0024

chloroform 67-66-3 119.38 Exp 1 0 10 0.022 .0152 .0107 .0127±.0033

methyl iodide 74-88-4 141.94 Exp 0 3 -0.56 -2.10 -2.76 -2.30±0.67

carbon tetrachloride 56-23-5 153.82 LM 0 1 0 0 0 0

chloropicrin (trichloro-nitromethane)76-06-2 164.38 Exp 1 2 0 1 1.85 1.04 1.13 1.13±0.20

methylene bromide 74-95-3 173.83 LM 0 1 0 0 0 0

acetylene 74-86-2 26.04 Exp 1 2 - 3 0.95 0.37 0.189 0.30±0.14

dimethyl amine 124-40-3 45.08 Exp 1 + 13 a,n 3.17 2.07 1.47 1.74±0.59

ethyl amine 75-04-7 45.08 Exp 1 + 13 a,n 5.78 3.10 1.99 2.58±0.78

ethanolamine 141-43-5 61.08 Exp 3a + 12 a,n 6.81 3.05 1.88 2.56±0.82

vinyl chloride 75-01-4 62.50 Exp 1 0 10 2.83 1.48 0.99 1.26±0.34

ethyl chloride 75-00-3 64.51 Exp 1 0 10 0.29 0.182 0.122 0.151±0.044

1,1-difluoroethane; HFC-152a 75-37-6 66.05 Exp 1 + 6 .0175 .0123 .0089 .0105±.0028

methyl isothiocyanate 556-61-6 73.12 Exp 1 2 0 2 0.32 0.21 0.180 0.195±0.027

nitroethane 79-24-3 75.07 Exp 1 0 7 0.063 0.044 0.032 0.038±0.010

dimethyl sulfoxide (DMSO) 67-68-5 78.13 Exp 1 2 -2,0 4 6.68 2.37 1.46 2.08±0.81

chloroacetaldehyde 107-20-0 78.50 Exp 1 0 7 12.30 3.52 1.74 3.00±1.71

1,1-dichloroethene 75-35-4 96.94 Exp 0 10 1.79 0.96 0.65 0.82±0.22

trans-1,2-dichloroethene 156-60-5 96.94 Exp 1 0 10 1.70 0.76 0.45 0.62±0.22

cis-1,2-dichloroethene 96.94 LM 0 10 1.70 0.76 0.45 0.62±0.22

1,1-dichloroethane 75-34-3 98.96 Exp 1 0 10 0.069 0.047 0.033 0.040±0.010

1,2-dichloroethane 107-06-2 98.96 Exp 1 0 10 0.21 0.103 0.061 0.083±0.028
Table B-1 (continued)

201

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

1,1,1,2-tetrafluoroethane; HFC134a811-97-2 102.03 Exp 1 0 6 .0007 .0007 .0006 .0007±.0001

ethyl bromide 74-96-4 108.97 Exp 1 0 20 0.129 0.082 0.055 0.068±0.020

trichloroethylene 79-01-6 131.39 Exp 1 2x +2 20 0.64 0.35 0.23 0.29±0.08

1,1,1-trichloroethane 71-55-6 133.40 Exp 1 0 10 .0049 .0031 .0021 .0026±.0006

1,1,2-trichloroethane 79-00-5 133.40 Exp 1 0 10 0.086 0.045 0.028 0.037±0.011

perchloroethylene 127-18-4 165.83 Exp 1 0 10 0.031 0.022 .0149 .0179±.0051

1,2-dibromoethane 106-93-4 187.86 Exp 1 0 20 0.102 0.049 0.029 0.040±0.013

methyl acetylene 74-99-7 40.06 Exp 1 - 7 6.72 2.45 1.37 2.06±0.86

acrylonitrile 107-13-1 53.06 Exp 1 0 10 2.24 1.08 0.72 0.93±0.25

trimethyl amine 75-50-3 59.11 Exp 1 + 13 a,n 6.32 3.05 1.95 2.57±0.79

isopropyl amine 75-31-0 59.11 Exp 4a + 12 a,n 7.23 3.32 2.09 2.80±0.86

1-amino-2-propanol 78-96-6 75.11 Exp + 13 a,n 5.42 2.64 1.71 2.23±0.66

3-chloropropene 76.52 Exp 0 10 12.22 3.84 2.05 3.28±1.60

1-nitropropane 108-03-2 89.09 Exp 0 8 0.22 0.158 0.116 0.135±0.029

2-nitropropane 79-46-9 89.09 Exp 1 0 6 0.110 0.071 0.049 0.059±0.019

chloroacetone 78-95-5 92.52 Exp 1 0 7 9.41 2.64 1.30 2.24±1.29

trans-1,3-dichloropropene 10061-02-6 110.97 Exp 1 2m 0 3 5.03 1.78 1.00 1.50±0.63

cis-1,3-dichloropropene 10061-01-5 110.97 Exp 1 2m 0 3 3.70 1.41 0.81 1.18±0.46

1,3-dichloropropene mixture 110.97 LM 1 2 0 2 4.29 1.57 0.90 1.32±0.53

1,2-dichloropropane 78-87-5 112.99 Exp 0 10 0.29 0.143 0.087 0.117±0.038

trans-1,3,3,3-tetrafluoropropene 1645-83-6 114.04 Exp 1 2 0 1 0.098 0.076 0.055 0.065±0.013

2,3,3,3-tetrafluoropropene 754-12-1 114.04 Exp 1 2 0 1 0.28 0.155 0.107 0.133±0.031

n-propyl bromide 106-94-5 122.99 Exp 1 2x -,+2 20 n 0.42 0.23 0.147 0.190±0.061

1,1,1,3,3-pentafluoropropane 460-73-1 134.05 Exp 1 0 6 .0008 .0006 .0004 .0005±.0001

3,3-dichloro-1,1,1,2,2-

pentafluoropropane;HCFC225ca

422-56-0 202.94 Exp 1 0 6 .0029 .0020 .0014 .0017±.0005

1,3-dichloro-1,1,2,2,3-

pentafluoropropane;HCFC225cb

507-55-1 202.94 Exp 1 0 6 .0011 .0007 .0005 .0006±.0002

1,3-butadiyne 460-12-8 50.06 Exp 0 11 5.76 2.64 1.73 2.26±0.73

1-buten-3-yne (vinyl acetylene) 689-97-4 52.07 LM 0 11 10.48 4.12 2.55 3.55±1.22

2-butyne 503-17-3 54.09 Exp 1 0 10 16.32 5.40 3.07 4.67±2.05

ethyl acetylene 107-00-6 54.09 Exp 1 - 7 6.11 2.23 1.25 1.87±0.78

tert-butyl amine 75-64-9 73.14 Exp 1 4a - 12 a -0.39 -0.83 -1.86 -1.41±0.68

morpholine 110-91-8 87.12 Exp + 13 a,n 1.98 1.21 0.84 1.01±0.35

ethyl methyl ketone oxime 

(methyl ethyl ketoxime)

96-29-7 87.12 Exp 0 10 1.58 1.32 1.47 1.42±0.33

dimethylaminoethanol 108-01-0 89.14 Exp 1 + 13 a,n 5.62 2.32 1.46 1.99±0.65

2-amino-1-butanol 96-20-8 89.14 Exp + 13 a,n 4.98 2.18 1.34 1.83±0.60

2-amino-2-methyl-1-propanol 124-68-5 89.14 Exp 3a - 12 a 0.25 -0.19 -1.03 -0.66±0.54

1-chlorobutane 109-69-3 92.57 Exp 0 10 1.10 0.63 0.40 0.52±0.15

diethanol-amine 111-42-2 105.14 Exp + 13 a,n 2.47 1.17 0.76 0.99±0.32

2-(chloro-methyl)-3-chloropropene1871-57-4 125.00 Exp 1 4 - 20 7.00 2.31 1.28 1.96±0.87

n-butyl bromide 109-65-9 137.02 Exp 1 2x -,+2 20 n 0.82 0.47 0.30 0.38±0.11

1,1,1,3,3-pentafluorobutane; 

HFC-365mfc

406-58-6 148.07 Exp 1 0 6 .0006 .0005 .0003 .0004±.0001
Table B-1 (continued)

202

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

2-amino-2-ethyl-1,3-

propanediol

115-70-8 119.16 Exp - 13 a 0.78 0.163 -0.44 -.161±0.380

n-methyl-2-pyrrolidone 872-50-4 99.13 Exp 1 2 0 2 2.41 1.24 0.74 1.00±0.34

methyl-nonafluoro-butyl ether 163702-07-6 234.06 Exp 0 8 0.055 0.044 0.032 0.037±0.008

methyl-nonafluoro-isobutyl 

ether

163702-08-7 234.06 LM 0 8 0.055 0.044 0.032 0.037±0.008

methoxy-perfluoro-n-butane 163702-07-6 250.06 Exp 1 0 6 .0006 .0005 .0003 .0004±.0001

methoxy-perfluoro-isobutene 163702-08-7 250.06 LM 1 0 6 .0006 .0005 .0003 .0004±.0001

1,1,1,2,2,3,4,5,5,5-

decafluoropentane; HFC-43-

10mee

138495-42-8 252.05 Exp 1 0 6 .0002 .0001 .0001 .0001±.0000

triethyl amine 121-44-8 101.19 Exp + 13 a,n 3.84 1.72 1.05 1.43±0.48

triethylene diamine 280-57-9 112.17 LM + 13 a,n 3.46 1.55 0.95 1.29±0.44

monochlorobenzene 108-90-7 112.56 Exp 1 0 8 0.32 0.043 -0.074 -.006±0.084

nitrobenzene 98-95-3 123.11 Exp 1 0 8 0.056 .0070 -0.014 -.002±0.015

p-dichlorobenzene 106-46-7 147.00 Exp 0 10 0.178 0.024 -0.042 -.004±0.047

o-dichlorobenzene 95-50-1 147.00 LM 0 8 0.178 0.024 -0.042 -.004±0.047

triethanolamine 102-71-6 149.19 Exp + 13 a,n 4.21 1.62 0.93 1.36±0.54

hexamethyl-disiloxane 107-46-0 162.38 Exp 1 3 0 5 -0.025 0.026 0.036 0.028±0.018

hydroxymethyl-disiloxane 164.35 Exp 1 3 0 5 -0.133 -0.011 0.021 -.001±0.036

hexafluoro-benzene 392-56-3 186.05 Exp 1 0 8 0.047 .0057 -0.012 -.002±0.013

ethoxy-perfluoro-n-butane 163702-05-4 264.09 Exp 1 0 6 .0082 .0049 .0032 .0040±.0011

ethoxy-perfluoro-isobutane 163702-06-5 264.09 Exp 1 0 6 .0098 .0059 .0038 .0049±.0013

ethyl nonafluorobutyl ether 163702-05-4 264.09 Exp + 8 0.21 0.132 0.088 0.109±0.026

ethyl nonafluoroisobutyl ether 163702-06-5 264.09 LM + 8 0.21 0.132 0.088 0.109±0.026

perfluoro-n-hexane 355-42-0 338.04 LM 0 1 0 0 0 0

2-chlorotoluene 95-49-8 126.58 LM 1 8 2.92 0.99 0.38 0.75±0.44

m-nitrotoluene 99-08-1 137.14 Exp 1 0 8 0.50 0.164 0.028 0.103±0.092

benzotrifluoride 98-08-8 146.11 Exp 1 0 8 0.29 0.108 0.040 0.079±0.047

p-trifluoromethyl-chlorobenzene98-56-6 180.55 Exp 1 0 8 0.126 0.046 .0173 0.034±0.020

p-toluene isocyanate 622-58-2 133.15 Exp 1 2 0 5 1.06 -0.085 -0.53 -0.25±0.34

3-(chloromethyl)-heptane 123-04-6 148.67 LM 0 10 0.95 0.60 0.32 0.44±0.17

cyclosiloxane D4 

(octamethylcyclotetrasiloxane)

556-67-2 296.62 Exp 1 3 0 5 -0.058 -0.011 .0029 -.006±0.014

2,4-toluene diisocyanate 584-84-9 174.16 Exp 1 2 0 5 -0.065 -0.52 -0.81 -0.64±0.23

2,6-toluene diisocyanate 91-08-7 174.16 LM 4 0 5 -0.065 -0.52 -0.81 -0.64±0.23

toluene diisocyanate (mixed 

isomers)

26471-62-5 174.16 LM 0 5 -0.065 -0.52 -0.81 -0.64±0.23

molinate (S-ethyl hexahydro1H-azepine-1-carbothioate)2212-67-1 187.30 Exp 0 7 1.51 0.74 0.46 0.62±0.20

EPTC (S-ethyl dipropylthiocarbamate)759-94-4 189.32 Exp 1 2 0 2 1.67 0.87 0.54 0.71±0.23

triisopropanolamine 122-20-3 191.27 Exp + 13 a,n 2.70 1.18 0.70 0.98±0.35

pebulate (S-propyl 

butylethylthiocarbamate)

1114-71-2 203.34 Exp 0 7 1.67 0.84 0.50 0.68±0.23

cyclosiloxane D5 

(decamethylcyclopentasiloxane)

541-02-6 370.77 Exp 1 4 0 5 -0.069 -0.013 .0030 -.008±0.017

thiobencarb (S-[4-chlorobenzyl] 

N,N-diethylthiolcarbamate)

28249-77-6 257.78 Exp 0 8 0.68 0.29 0.110 0.20±0.11
Table B-1 (continued)

203

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

methylene diphenylene 

diisocyanate

101-68-8 250.25 Exp 0 8 0.89 0.021 -0.30 -.100±0.240

lauryl pyrrolidone 2687-96-9 253.42 LM 0 11 0.94 0.48 0.29 0.39±0.13

CARB Hydrocarbon Bins

CARB Hydrocarbon Bin 1 14.25 Mix 0 7 c 1.42 0.90 0.55 0.72±0.22

CARB Hydrocarbon Bin 2 14.37 Mix 0 7 c 1.31 0.85 0.53 0.68±0.20

CARB Hydrocarbon Bin 3 14.03 Mix 0 7 c 1.63 1.01 0.60 0.80±0.26

CARB Hydrocarbon Bin 4 14.19 Mix 0 7 c 1.47 0.90 0.53 0.71±0.23

CARB Hydrocarbon Bin 5 14.06 Mix 0 7 c 1.56 0.88 0.50 0.69±0.23

CARB Hydrocarbon Bin 6 14.18 Mix 0 7 c 1.17 0.72 0.35 0.52±0.23

CARB Hydrocarbon Bin 7 14.26 Mix 0 7 c 1.03 0.66 0.32 0.47±0.21

CARB Hydrocarbon Bin 8 14.03 Mix 0 7 c 1.44 0.84 0.43 0.62±0.26

CARB Hydrocarbon Bin 9 14.13 Mix 0 7 c 1.44 0.79 0.39 0.58±0.25

CARB Hydrocarbon Bin 10 14.04 Mix 0 7 c 1.98 0.94 0.45 0.70±0.30

CARB Hydrocarbon Bin 11 14.14 Mix 0 8 c 0.70 0.46 0.174 0.30±0.18

CARB Hydrocarbon Bin 12 14.20 Mix 0 8 c 0.62 0.42 0.150 0.26±0.17

CARB Hydrocarbon Bin 13 14.03 Mix 0 8 c 0.86 0.53 0.22 0.36±0.20

CARB Hydrocarbon Bin 14 14.10 Mix 0 8 c 0.99 0.54 0.22 0.37±0.19

CARB Hydrocarbon Bin 15 14.02 Mix 0 8 c 1.57 0.72 0.32 0.52±0.24

CARB Hydrocarbon Bin 16 14.11 Mix 0 8 c 0.52 0.35 0.131 0.22±0.15

CARB Hydrocarbon Bin 17 14.16 Mix 0 8 c 0.48 0.33 0.122 0.21±0.14

CARB Hydrocarbon Bin 18 14.03 Mix 0 8 c 0.60 0.39 0.148 0.25±0.16

CARB Hydrocarbon Bin 19 14.09 Mix 0 8 c 0.66 0.39 0.150 0.26±0.15

CARB Hydrocarbon Bin 20 14.03 Mix 0 10 c 0.95 0.46 0.190 0.33±0.17

CARB Hydrocarbon Bin 21 13.27 Mix 0 8 c 7.64 2.49 1.16 2.01±1.03

CARB Hydrocarbon Bin 22 13.36 Mix 0 8 c 7.60 2.55 1.31 2.12±0.98

CARB Hydrocarbon Bin 23 13.41 Mix 0 10 c 6.85 2.31 1.21 1.93±0.88

CARB Hydrocarbon Bin 24 13.47 Mix 0 11 c 3.82 1.27 0.63 1.04±0.50

Other Complex Mixtures

Base ROG Mixture 14.44 Mix 0 7 3.60 1.44 0.81 1.19±0.45

final LEV – RFA 14.03 Mix 0 7 3.54 1.41 0.76 1.15±0.45

TLEV Exhaust -- RFA 14.04 Mix 0 7 3.98 1.55 0.84 1.27±0.51

TLEV exhaust – phase 2 14.12 Mix 0 7 3.89 1.53 0.84 1.26±0.49

Final LEV -- Phase 2 14.22 Mix 0 7 3.45 1.39 0.76 1.13±0.44

TLEV Exhaust -- LPG 14.86 Mix 0 7 2.04 0.89 0.55 0.75±0.24

TLEV Exhaust -- CNG 15.22 Mix 0 7 0.73 0.35 0.22 0.29±0.08

TLEV Exhaust -- E-85 20.74 Mix 0 7 2.55 1.19 0.76 1.01±0.30

TLEV Exhaust -- M-85 27.45 Mix 0 7 1.56 0.59 0.33 0.49±0.20

composite mineral spirit 

(naphthas or lactol spirits) 

(CARB Profile ID 802)

14.06 Mix 0 7 1.92 0.87 0.41 0.66±0.29

Safety-Kleen Mineral Spirits 

"A" (Type I-B, 91% Alkanes)

14.08 Mix 2 0,+ 7 1.25 0.65 0.29 0.46±0.22

Safety-Kleen Mineral Spirits 

"B" (Type II-C)

14.10 Mix 2 0,+ 7 0.70 0.45 0.171 0.29±0.18

Safety-Kleen Mineral Spirits 

"C" (Type II-C)

14.11 Mix 2 0,+ 7 0.71 0.46 0.173 0.30±0.18

Exxon Exxol® D95 Fluid 14.11 Mix 2 0 7 0.60 0.40 0.146 0.25±0.16
Table B-1 (continued)

204

Description CAS MWt Codes [a] Reactivity (gm O3 / gm VOC)

Rep k a Expt Bias Unc MIR MOIR EBIR Base

Safety-Kleen Mineral Spirits 

"D" (Type II-C)

14.12 Mix 2 0,+ 7 0.71 0.46 0.173 0.30±0.18

Exxon Isopar® M Fluid 14.15 Mix 2 0 8 0.57 0.38 0.136 0.24±0.16

thinning solvent/mineral spirits 

(Cal Poly SLO 1996)

14.40 Mix 0 7 1.93 0.91 0.46 0.69±0.28

Aromatic 100® 13.36 Mix 2 0 7 7.38 2.47 1.25 2.04±0.96

Kerosene 13.94 Mix 2 0 7 1.62 0.73 0.33 0.54±0.24

Regular mineral spirits 13.97 Mix 2 0 7 1.89 0.84 0.39 0.63±0.28

Reduced Aromatics Mineral 

Spirits

14.05 Mix 2 0 7 1.19 0.64 0.28 0.45±0.22

Dearomatized Alkanes, mixed, 

predominately C10-C12

14.09 Mix 2 0 7 0.87 0.54 0.23 0.37±0.20

VMP Naphtha 14.16 Mix 2 0 7 1.23 0.74 0.36 0.53±0.23

Synthetic isoparaffinic alkane 

mixture, predominately C10-

C12

14.20 Mix 2 0 8 0.75 0.49 0.195 0.32±0.18

Oxo-Tridecyl Acetate 16.19 Mix 0 7 0.55 0.35 0.123 0.22±0.14

Oxo-Dodecyl Acetate 16.30 Mix 0 7 0.59 0.37 0.139 0.24±0.15

Oxo-Decyl Acetate 16.71 Mix 2 0 7 0.70 0.44 0.187 0.30±0.16

Oxo-Nonyl Acetate 16.89 Mix 0 7 0.72 0.45 0.193 0.31±0.16

Oxo-Octyl Acetate 17.23 Mix 0 7 0.81 0.50 0.24 0.36±0.16

Oxo-Heptyl Acetate 17.58 Mix 0 7 0.83 0.51 0.26 0.37±0.16

Oxo-Hexyl Acetate 18.02 Mix 0 7 0.86 0.54 0.30 0.41±0.15

turpentine 8006-64-2 13.62 Mix 0 7 4.28 1.60 0.87 1.33±0.56

soy methyl esters; alkyl C16-

C18 methyl esters

15.57 Mix 0 8 1.58 0.69 0.40 0.57±0.22

[a] Codes used in this tabulation are as follows:

"Rep" ... Codes for method used to represent the VOC in the mechanism

Exp An explicit mechanism assignment has been made for this compound or model species. 

See Table B-2 for the mechanism.

AdjP An explicit mechanism assignment has been made for this compound and the adjusted 

product version of the mechanism has been used when calculating its atmospheric 

reactivity values. The adjusted product mechanism is given in Table B-3.

LM This compound is represented using the "Lumped Molecule" method. See Table B-9.

Mix This is represented by a complex mixture of detailed model species. The compositions of 

these mixtures are given in Table B-10.

"k a" ... Codes indicating of measurement data for the reaction rate constants

1 The OH radical rate constant has been measured. See Table B-2 or Table B-4 for the rate 

constant and reference citation. If the compound is consumed primarily by photolysis, 

this code means that absorption cross-section and quantum yield are available. In this 

case, see Table B-6 for the photolysis set, overall quantum yields (if applicable) and 

documentation, and Table A-3 or Table B-8 for the absorption cross sections and (if 

applicable) wavelength-dependent quantum yields.

blank The OH radical rate constant or (if primarily photoreactive) the photolysis rate 

parameters had to be estimated. See Table B-2 or Table B-4 for the estimated OH rate 

constant and documentation on how the estimate was made, and Table B-6 for the 

method used to estimate the photolysis rate.
Table B-1 (continued)

205

"Expt" ... Environmental Chamber Data Availability Codes (if blank, no suitable evaluation data are available).

1 Extensive evaluation data for a variety of conditions.

2 Sufficient data available. At least 2 and often 3 types of evaluation experiments to test 

data under different conditions.

3 Limited evaluation data; usually representing one set of conditions, or some 

inconsistencies in evaluation results.

3a Evaluation data exist for 2 or more sets of conditions, but uncertainties exist concerning 

amount of compound available to react in the gas phase. See Carter (2008).

4 Data from only a single experiment is available, results from different experiments gave 

inconsistent results, or problems exist with the data.

4a Data from only a single experiment is available, and uncertainties exist concerning the 

amount of compound available for reaction in the gas phase. See Carter (2008).

m This compound was studied in a mixture with the other isomer. Since the reactivities of 

the two isomers are different, the uncertainty classification has been increased over that 

of the mixture that was studied.

x No attempt was made to improve the mechanism performance to fit the available data.

"Bias" ... Probable reactivity prediction bias codes (if blank, this compound has not been rated) 

Chamber data available No chamber data available

0 No apparent bias Direction of bias is unknown

+ Some indication of positive bias Positive bias considered to be more likely than not

- Some indication of negative bias Negative bias is considered to be more likely than 

not

2 Bias found to be relatively large Bias may be relatively large

x,x If two codes given, first indicates observed or probable bias for predictions of rates of 

NO oxidation and O3 formation, which is important in affecting MIR reactivity, and the 

second indicates observed or probable bias for low NOx conditions. E.g. "0,+" if chamber 

data available indicates that the model simulated rates of NO oxidation and O3 formation 

but overpredicted final O3 yields in NOx-limited experiments. 

? There is some inconsistency in the data concerning this bias indication (or lack thereof), 

or the bias is unknown but may be large.

a The reactivity predictions and representation in the mechanism is based on the 

assumption that this compound is completely available for reaction in the gas phase. This 

is likely not to be the case for this compound. Thus the reactivity estimate may be high 

for compounds that have positive O3 impacts and low for compounds that are calculated 

to be inhibitors.

"Unc" ... Uncertainty codes (if blank, this compound has not been rated)

The following codes are used when experimental data are available to evaluate the reactivity 

predictions of the mechanism and the mechanism was (or would have been) adjusted to fit the data 

as appropriate to improve the fits.

1 The mechanism appears to be reasonably well established or at least its predictions 

appear to be are reasonably well evaluated. This does not rule out possible changes in 

reactivity values if the base mechanism, scenario conditions, or reactivity metrics are 

changed. Also used for compounds known or expected to be inert or to have upper limit 

reactivities much less than methane.

2 The mechanism has been evaluated at least to some extent, rate constant data are 

available for its major reactions, and is not considered to have large uncertainties. If a 

likely bias is indicated it is probably not large.
Table B-1 (continued)

206

3 The mechanism has been evaluated at least to some extent and rate constant data are 

available for its major reactions, but the mechanism has some uncertainties or apparent 

inconsistencies with available laboratory data, or there are some uncertainties in the 

evaluation data. If a likely bias is indicated it is probably not large.

4 The mechanism has been evaluated at least to some extent and rate constant data are 

available for its major reactions, but the mechanism has some uncertainties, apparent 

inconsistencies with available laboratory data exist that may be significant, or the 

available evaluation database is limited or has problems. If a likely bias of 1 is indicated 

it is probably not large.

5 A highly parameterized mechanism has been adjusted to simulate chamber data. The 

appropriateness of the parameterization, and its ability to extrapolate to ambient 

conditions, is uncertain.

The following codes are used for compounds for which no experimental data exist to evaluate 

reactivity predictions of the mechanism, or where such data, if any, were not taken into account 

when developing the mechanism.

6 The mechanism has not been evaluated but at least the important reaction rate(s) have 

been measured and the methods used to estimate the mechanism have been found to 

generally perform reasonably well for compounds where evaluation data are available, or 

the mechanisms are not expected to be highly complex. If a likely bias is indicated it is 

based on evaluation results for similar compounds.

7 The mechanism has not been evaluated and the reaction rates had to be estimated, but the 

methods used to estimate the rate constant(s) and mechanism have been found to 

generally perform reasonably well for compounds where evaluation data are available. If 

a likely bias is indicated it is based on evaluation results for similar compounds. This 

code is also used for mixture or lumped molecule or mixture representations that are 

considered to be reasonably appropriate.

8 The estimated mechanism and/or relevant rate constant(s) or photolysis rates have some 

uncertainties, but mechanisms based on similar assumptions have been found to perform 

satisfactorily for related compounds, or the mechanisms are not expected to be highly 

complex. The applicability of these assumptions to this compound, or the extrapolation 

of mechanisms for smaller compounds to one of this size, has some uncertainty. This 

code is also used for mixture or lumped molecule representations whose appropriateness 

has some uncertainty.

The uncertainty codes below mean that use of the reactivity values in regulatory applications is 

problematical.

10 The estimated mechanism is sufficiently uncertain that it needs to be evaluated. This 

code is also used for mixture or lumped molecule representations whose appropriateness 

is considered to be highly uncertain. However, the representation employed is the current 

best estimate, and the direction of the bias is unknown.

11 The estimated mechanism is extremely uncertain that it needs to be evaluated. This code 

is also used for mixture or lumped molecule representations whose appropriateness is 

questionable, but no better alternative exists, and the bias of using the representation is 

unknown. However, the representation employed is the current best estimate, and the 

direction of the bias is unknown.
Table B-1 (continued)

207

12 An estimated mechanism for the gas-phase reactions for this compound has been 

developed and has been evaluated at least qualitatively against available chamber data, 

but its estimated atmospheric ozone impact is highly uncertain because the amount of 

emitted compound available for reaction in the gas-phase is unknown. One important 

issue is that this compound may be removed by gas-phase reaction with HNO3, whose 

presence depends on ambient conditions and may not be appropriately represented in the 

scenarios used for reactivity assessment. For such compounds two reactivity values are 

given, and "upper limit magnitude" reactivity value based on assuming that all the 

emitted VOC is available for gas-phase reaction and that reaction with HNO3 is 

negligible (as may be applicable if the HNO3 formed in gas-phase reactions is removed 

from the gas phase by other means) and one also assuming that all the emitted VOC is 

available for gas-phase reaction except that the reaction with gas-phase HNO3 is fast and 

there is no other sink for HNO3 formed in the gas-phase reactions.

13 Same as code 12 except that no chamber data are available to test the estimated gas-phase 

mechanism.

20 The representation or estimated mechanism used is considered to be biased, and the 

direction of the likely bias is indicted by the bias code. Best estimate mechanisms have 

not been developed.

Additional codes used where applicable

s Portions of the mechanism are unknown or highly uncertain and simplified or 

parameterized representation has been adjusted at lest in part to fit available data for this 

or relate compounds. This is used primarily for alkylbenzenes.

d Portions of this mechanism appear to be inconsistent with available laboratory data. This 

is used primarily for the 1-alkenes, where radical yields in O3 reactions have to be 

reduced to simulate chamber data.

u The mechanism is unknown and a parameterized mechanism adjusted to fit the data for 

this or related compounds employed.

m This uncertainty code is only applicable for mixtures whose composition has been 

analyzed using state-of-the-science methods. Rating of effects of compositional 

uncertainties is beyond the scope of the project (but see discussion in Carter and Malkina 

(2005) for hydrocarbon mixtures).

b The reactivity predictions may be more sensitive than usual to changes in the base 

mechanism or scenario conditions.

n Chamber data for this or related compounds suggest that the mechanism may overpredict 

ozone under conditions where NOx is limited. This should affect MIR values but will 

lead to too high reactivities in lower NOx scenarios.

a This compound may react with HNO3 to form a non-volatile salt, which may reduce the 

availability for this compound to react in the gas phase. The importance of this process 

under atmospheric conditions is uncertain because (a) the salt may revolatilize to the gasphase species and the equilibrium constant is unknown, (b) the sources and other sinks 

for HNO3 may vary significantly from scenario to scenario and have not been established 

for the reactivity assessment scenarios, and (c) if ammonia or other amines are present 

they may compete for the HNO3 and reduce the importance of this process for this amine, 

and the importance of these processes have not been established for the reactivity 

scenarios. In order to derive an upper limit ozone impact estimate, the reactivities of 

these compounds have been calculated assuming that removal by reaction with HNO3 is 

uncertain. If this process is important, the magnitude of the actual ozone impact may be 

an order of magnitude or more low. Therefore, the tabulated reactivity values are upper 

limits for positively reactive compounds, and lower limits for ozone inhibitors.

c CARB hydrocarbon bins are defined as described by Kwok et al (2000), but their 

reactivities are calculated based on their estimated compositions, which are derived as 

discussed by Carter (2009c). The uncertainties involved with this derivation are also 

discussed by Carter (2009c).
Table B-1 (continued)

208

+ This may appropriately be considered to be an upper limit estimate in the ozone impact 

of this compound.

-- This may appropriately be considered to be an upper limit estimate in the amount of 

ozone inhibition caused by this compound. The upper limit reactivity is zero.
209

Table B-2. Listing of mechanisms for all VOCs for which mechanism assignments have been 

derived. (Available in electronic form only)

Because of the size of this table, it is only available in as 

supplementary material in electronic form. See Appendix D.

(The room temperature rate constant and photolysis parameter assignments and their reference 

citations that are incorporated in this table are also given in Table B-4 through Table B-6)

Table B-3. Listing of adjusted product mechanisms for all VOCs for which such mechanisms have 

been derived. (Available in electronic form only)

Because of the size of this table, it is only available in as 

supplementary material in electronic form. See Appendix D.
210

Table B-4. Listing of compounds for which mechanisms have been derived. 1. OH radical rate 

constants at 300oK, mechanism types, and structures used for compounds with generated 

mechanisms.

Compound kOH [a] MecStructure [c] k(300) Ref [b]

Methane 6.62E-15 1 1

Ethane 2.54E-13 1 2 CH3CH3

Propane 1.11E-12 1 2 CH3CH2CH3

Cyclopropane 8.34E-14 1 2 CH2*CH2CH2*

n-Butane 2.38E-12 1 2 CH3CH2CH2CH3

Isobutane 2.14E-12 1 2 CH3CH(CH3)CH3

Cyclobutane 2.05E-12 1 2 CH2*CH2CH2CH2*

n-Pentane 3.84E-12 1 2 CH3CH2CH2CH2CH3

Neopentane 8.38E-13 1 2 CH3C(CH3)(CH3)CH3

Iso-Pentane 3.60E-12 1 2 CH3CH2CH(CH3)CH3

Cyclopentane 5.02E-12 1 2,A CH2*CH2CH2CH2CH2*

n-Hexane 5.25E-12 1 2 CH3CH2CH2CH2CH2CH3

2,2-Dimethyl Butane 2.27E-12 1 2 CH3CH2C(CH3)(CH3)CH3

2,3-Dimethyl Butane 5.79E-12 1 2 CH3CH(CH3)CH(CH3)CH3

2-Methyl Pentane 5.20E-12 1 2 CH3CH2CH2CH(CH3)CH3

3-Methylpentane 5.20E-12 1 2 CH3CH2CH(CH3)CH2CH3

Cyclohexane 7.02E-12 1 2,A CH2*CH2CH2CH2CH2CH2*

Isopropyl Cyclopropane 2.61E-12 1 2 CH3CH(CH3)CH*CH2CH2*

Methylcyclopentane 5.68E-12 e1 2,A CH3CH*CH2CH2CH2CH2*

n-Heptane 6.81E-12 1 2 CH3CH2CH2CH2CH2CH2CH3

2,2,3-Trimethyl Butane 3.82E-12 1 2 CH3CH(CH3)C(CH3)(CH3)CH3

2,2-Dimethyl Pentane 3.40E-12 2 2 CH3CH2CH2C(CH3)(CH3)CH3

2,3-Dimethyl Pentane 7.15E-12 e1 2 CH3CH2CH(CH3)CH(CH3)CH3

2,4-Dimethyl Pentane 4.77E-12 1 2 CH3CH(CH3)CH2CH(CH3)CH3

2-Methyl Hexane 6.89E-12 e1 2,A CH3CH2CH2CH2CH(CH3)CH3

3,3-Dimethyl Pentane 3.00E-12 e1 2 CH3CH2C(CH3)(CH3)CH2CH3

3-Methyl Hexane 7.17E-12 e1 2 CH3CH2CH2CH(CH3)CH2CH3

3-ethylpentane 7.58E-12 e1 2 CH3CH2CH(CH2CH3)CH2CH3

1,1-dimethylcyclopentane 3.98E-12 e1 2,A CH3C*(CH3)CH2CH2CH2CH2*

1,2-dimethylcyclopentane 6.82E-12 e1 2,A CH3CH*CH2CH2CH2CH*CH3

1,3-Dimethyl Cyclopentane 6.82E-12 e1 2,A CH3CH*CH2CH2CH(CH3)CH2*

Cycloheptane 1.24E-11 1 2,A CH2*CH2CH2CH2CH2CH2CH2*

Ethyl Cyclopentane 7.27E-12 e1 2,A CH3CH2CH*CH2CH2CH2CH2*

Methylcyclohexane 9.64E-12 1 2,A CH3CH*CH2CH2CH2CH2CH2*

n-Octane 8.16E-12 1 2 CH3CH2CH2CH2CH2CH2CH2CH3

2,2,3,3-Tetramethyl Butane 9.89E-13 1 2 CH3C(CH3)(CH3)C(CH3)(CH3)CH3

2,2,4-Trimethyl Pentane 3.38E-12 1 2 CH3CH(CH3)CH2C(CH3)(CH3)CH3

2,2-Dimethyl Hexane 4.80E-12 2 2 CH3CH2CH2CH2C(CH3)(CH3)CH3

2,3,4-Trimethyl Pentane 6.60E-12 1 2 CH3CH(CH3)CH(CH3)CH(CH3)CH3

2,3-Dimethyl Hexane 8.57E-12 e1 2 CH3CH2CH2CH(CH3)CH(CH3)CH3

2,4-Dimethyl Hexane 8.57E-12 e1 2 CH3CH2CH(CH3)CH2CH(CH3)CH3

2,5-Dimethyl Hexane 8.29E-12 e1 2 CH3CH(CH3)CH2CH2CH(CH3)CH3

2-Methyl Heptane 8.31E-12 e1 2 CH3CH2CH2CH2CH2CH(CH3)CH3

3-Methyl Heptane 8.59E-12 e1 2 CH3CH2CH2CH2CH(CH3)CH2CH3

4-Methyl Heptane 8.59E-12 e1 2 CH3CH2CH2CH(CH3)CH2CH2CH3
Table B-4 (continued)

211

Compound kOH [a] MecStructure [c] k(300) Ref [b]

2,3,3-trimethylpentane 4.40E-12 e1 2 CH3CH2C(CH3)(CH3)CH(CH3)CH3

3,3-dimethyl hexane 4.42E-12 e1 2 CH3CH2CH2C(CH3)(CH3)CH2CH3

2,2,3-trimethyl-pentane 4.94E-12 e1 2 CH3CH2CH(CH3)C(CH3)(CH3)CH3

3,4-dimethylhexane 8.85E-12 e1 2 CH3CH2CH(CH3)CH(CH3)CH2CH3

3-Ethyl 2-Methyl Pentane 8.98E-12 e1 2 CH3CH2CH(CH2CH3)CH(CH3)CH3

1,1,2-trimethylcyclopentane 5.11E-12 e1 2 CH3CH*CH2CH2CH2C*(CH3)CH3

1,1,3-trimethylcyclopentane 5.11E-12 e1 2 CH3CH*CH2CH2C(CH3)(CH3)CH2*

1,1-Dimethyl Cyclohexane 7.44E-12 e1 2 CH3C*(CH3)CH2CH2CH2CH2CH2*

1,2,3-trimethylcyclopentane 7.95E-12 e1 2 CH3CH*CH2CH2CH(CH3)CH*CH3

1,2,4-trimethylcyclopentane 7.95E-12 e1 2 CH3CH*CH2CH(CH3)CH(CH3)CH2*

1-methyl-3-ethylcyclopentane 8.40E-12 e1 2,A CH3CH2CH*CH2CH2CH(CH3)CH2*

1,2-dimethylcyclohexane 1.19E-11 e1 2,A CH3CH*CH2CH2CH2CH2CH*CH3

1,4-dimethylcyclohexane 1.19E-11 e1 2,A CH3CH*CH2CH2CH(CH3)CH2CH2*

1,3-Dimethyl Cyclohexane 1.19E-11 e1 2,A CH3CH*CH2CH2CH2CH(CH3)CH2*

Cyclooctane 1.33E-11 1 2,A CH2*CH2CH2CH2CH2CH2CH2CH2*

Ethylcyclohexane 1.20E-11 e1 2 CH3CH2CH*CH2CH2CH2CH2CH2*

Propyl Cyclopentane 8.69E-12 e1 2,A CH3CH2CH2CH*CH2CH2CH2CH2*

n-Nonane 9.75E-12 1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH3

2,2,5-Trimethyl Hexane 6.08E-12 e1 2 CH3CH(CH3)CH2CH2C(CH3)(CH3)CH3

2,3,5-Trimethyl Hexane 7.90E-12 2 2,A CH3CH(CH3)CH2CH(CH3)CH(CH3)CH3

2,4-Dimethyl Heptane 9.99E-12 e1 2 CH3CH2CH2CH(CH3)CH2CH(CH3)CH3

2-Methyl Octane 1.01E-11 2 2 CH3CH2CH2CH2CH2CH2CH(CH3)CH3

3,3-Diethyl Pentane 4.80E-12 1 2 CH3CH2C(CH2CH3)(CH2CH3)CH2CH3

3,5-Dimethyl Heptane 1.03E-11 e1 2 CH3CH2CH(CH3)CH2CH(CH3)CH2CH3

4-Ethyl Heptane 1.04E-11 e1 2 CH3CH2CH2CH(CH2CH3)CH2CH2CH3

4-Methyl Octane 9.70E-12 2 2 CH3CH2CH2CH2CH(CH3)CH2CH2CH3

2,4,4-trimethylhexane 5.82E-12 e1 2 CH3CH2C(CH3)(CH3)CH2CH(CH3)CH3

3,3-dimethylheptane 5.84E-12 e1 2 CH3CH2CH2CH2C(CH3)(CH3)CH2CH3

4,4-dimethyl heptane 5.84E-12 e1 2 CH3CH2CH2C(CH3)(CH3)CH2CH2CH3

2,2-dimethyl heptane 6.10E-12 e1 2 CH3CH2CH2CH2CH2C(CH3)(CH3)CH3

2,2,4-trimethylhexane 6.36E-12 e1 2 CH3CH2CH(CH3)CH2C(CH3)(CH3)CH3

2,6-dimethylheptane 9.71E-12 e1 2 CH3CH(CH3)CH2CH2CH2CH(CH3)CH3

2,3-dimethylheptane 9.99E-12 e1 2 CH3CH2CH2CH2CH(CH3)CH(CH3)CH3

2,5-dimethylheptane 9.99E-12 e1 2 CH3CH2CH(CH3)CH2CH2CH(CH3)CH3

3-methyloctane 1.00E-11 e1 2 CH3CH2CH2CH2CH2CH(CH3)CH2CH3

3,4-dimethylheptane 1.03E-11 e1 2 CH3CH2CH2CH(CH3)CH(CH3)CH2CH3

3-ethylheptane 1.04E-11 e1 2 CH3CH2CH2CH2CH(CH2CH3)CH2CH3

Cis-hydrindane; 

Bicyclo[4.3.0]nonane

1.71E-11 e1 2,A CH2*1CH2CH2CH*2CH2CH2CH2CH*2CH2*1

1,2,3-trimethylcyclohexane 1.36E-11 e1 2,A CH3CH*CH2CH2CH2CH(CH3)CH*CH3

1,3,5-trimethylcyclohexane 1.36E-11 e1 2 CH3CH*CH2CH(CH3)CH2CH(CH3)CH2*

1,1,3-Trimethyl Cyclohexane 8.70E-12 2 2 CH3CH*CH2CH2CH2C(CH3)(CH3)CH2*

1-Ethyl-4-Methyl 

Cyclohexane

1.37E-11 e1 2,A CH3CH2CH*CH2CH2CH(CH3)CH2CH2*

Propyl Cyclohexane 1.34E-11 e1 2 CH3CH2CH2CH*CH2CH2CH2CH2CH2*

n-Decane 1.10E-11 1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3

2,4,6-Trimethyl Heptane 1.14E-11 e1 2 CH3CH(CH3)CH2CH(CH3)CH2CH(CH3)CH3

2,4-Dimethyl Octane 1.14E-11 e1 2 CH3CH2CH2CH2CH(CH3)CH2CH(CH3)CH3

2,6-Dimethyl Octane 1.29E-11 3 2 CH3CH2CH(CH3)CH2CH2CH2CH(CH3)CH3
Table B-4 (continued)

212

Compound kOH [a] MecStructure [c] k(300) Ref [b]

2-Methyl Nonane 1.28E-11 3 2 CH3CH2CH2CH2CH2CH2CH2CH(CH3)CH3

3,4-Diethyl Hexane 6.92E-12 1 2 CH3CH2CH(CH2CH3)CH(CH2CH3)CH2CH3

3-Methyl Nonane 1.14E-11 e1 2 CH3CH2CH2CH2CH2CH2CH(CH3)CH2CH3

4-Methyl Nonane 1.14E-11 e1 2 CH3CH2CH2CH2CH2CH(CH3)CH2CH2CH3

4-Propyl Heptane 1.18E-11 e1 2 CH3CH2CH2CH(CH2CH2CH3)CH2CH2CH3

2,4,4-trimethylheptane 7.24E-12 e1 2 CH3CH2CH2C(CH3)(CH3)CH2CH(CH3)CH3

2,5,5-trimethylheptane 7.24E-12 e1 2 CH3CH2C(CH3)(CH3)CH2CH2CH(CH3)CH3

3,3-dimethyloctane 7.26E-12 e1 2 CH3CH2CH2CH2CH2C(CH3)(CH3)CH2CH3

4,4-dimethyloctane 7.26E-12 e1 2 CH3CH2CH2CH2C(CH3)(CH3)CH2CH2CH3

2,2-dimethyloctane 7.52E-12 e1 2 CH3CH2CH2CH2CH2CH2C(CH3)(CH3)CH3

2,2,4-trimethylheptane 7.78E-12 e1 2 CH3CH2CH2CH(CH3)CH2C(CH3)(CH3)CH3

2,2,5-trimethylheptane 7.78E-12 e1 2 CH3CH2CH(CH3)CH2CH2C(CH3)(CH3)CH3

2,3,6-trimethylheptane 1.14E-11 e1 2,A CH3CH(CH3)CH2CH2CH(CH3)CH(CH3)CH3

2,3-dimethyloctane 1.14E-11 e1 2 CH3CH2CH2CH2CH2CH(CH3)CH(CH3)CH3

2,5-dimethyloctane 1.14E-11 e1 2 CH3CH2CH2CH(CH3)CH2CH2CH(CH3)CH3

2-methyl-3-ethylheptane 1.18E-11 e1 2 CH3CH2CH2CH2CH(CH2CH3)CH(CH3)CH3

4-ethyloctane 1.18E-11 e1 2,A CH3CH2CH2CH2CH(CH2CH3)CH2CH2CH3

1,3-Diethyl-Cyclohexane 1.55E-11 e1 2,A CH3CH2CH*CH2CH2CH2CH(CH2CH3)CH2*

1,4-Diethyl-Cyclohexane 1.55E-11 e1 2 CH3CH2CH*CH2CH2CH(CH2CH3)CH2CH2*

1-Methyl-3-Isopropyl 

Cyclohexane

1.51E-11 e1 2 CH3CH*CH2CH2CH2CH(CH2*)CH(CH3)CH3

Butyl Cyclohexane 1.47E-11 1 2 CH3CH2CH2CH2CH*CH2CH2CH2CH2CH2*

n-Undecane 1.23E-11 1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3

2,3,4,6-Tetramethyl Heptane 1.31E-11 e1 2 CH3CH(CH3)CH2CH(CH3)CH(CH3)CH(CH3)CH3

2,6-Dimethyl Nonane 1.28E-11 e1 2 CH3CH2CH2CH(CH3)CH2CH2CH2CH(CH3)CH3

3,5-Diethyl Heptane 1.39E-11 e1 2 CH3CH2CH(CH2CH3)CH2CH(CH2CH3)CH2CH3

3-Methyl Decane 1.29E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH(CH3)CH2CH3

4-Methyl Decane 1.29E-11 e1 2 CH3CH2CH2CH2CH2CH2CH(CH3)CH2CH2CH3

1,3-Diethyl-5-Methyl 

Cyclohexane

1.72E-11 e1 2 CH3CH2CH*CH2CH(CH3)CH2CH(CH2CH3)CH2*

1-Ethyl-2-Propyl Cyclohexane 1.70E-11 e1 2,A CH3CH2CH2CH*CH2CH2CH2CH2CH*CH2CH3

Pentyl Cyclohexane 1.63E-11 e1 2 CH3CH2CH2CH2CH2CH*CH2CH2CH2CH2CH2*

n-Dodecane 1.32E-11 1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3

2,3,5,7-Tetramethyl Octane 1.45E-11 e1 2 CH3CH(CH3)CH2CH(CH3)CH2CH(CH3)CH(CH3)CH3

2,6-Diethyl Octane 1.53E-11 e1 2 CH3CH2CH(CH2CH3)CH2CH2CH(CH2CH3)CH2CH3

3,6-Dimethyl Decane 1.45E-11 e1 2,A CH3CH2CH2CH2CH(CH3)CH2CH2CH(CH3)CH2CH3

3-Methyl Undecane 1.43E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH(CH3)CH2CH3

5-Methyl Undecane 1.43E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH(CH3)CH2CH2CH2CH3

1,3,5-Triethyl Cyclohexane 1.90E-11 e1 2 CH3CH2CH*CH2CH(CH2CH3)CH2CH(CH2CH3)CH2*

1-Methyl-4-Pentyl 

Cyclohexane

1.80E-11 e1 2 CH3CH2CH2CH2CH2CH*CH2CH2CH(CH3)CH2CH2*

Hexyl Cyclohexane 1.78E-11 3 2,A CH3CH2CH2CH2CH2CH2CH*CH2CH2CH2CH2CH2*

n-Tridecane 1.51E-11 1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3

2,3,6-Trimethyl 4-Isopropyl 

Heptane

1.63E-11 e1 2 CH3CH(CH3)CH2CH(CH(CH3)CH3)CH(CH3)CH(CH3)CH3

2,4,6,8-Tetramethyl Nonane 1.59E-11 e1 2,A CH3CH(CH3)CH2CH(CH3)CH2CH(CH3)CH2CH(CH3)CH3

3,6-Dimethyl Undecane 1.60E-11 e1 2 CH3CH2CH2CH2CH2CH(CH3)CH2CH2CH(CH3)CH2CH3

3,7-Diethyl Nonane 1.68E-11 e1 2 CH3CH2CH(CH2CH3)CH2CH2CH2CH(CH2CH3)CH2CH3

3-Methyl Dodecane 1.57E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH(CH3)CH2CH3
Table B-4 (continued)

213

Compound kOH [a] MecStructure [c] k(300) Ref [b]

5-Methyl Dodecane 1.57E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH2CH(CH3)CH2CH2CH2CH3

1,3-Diethyl-5-Propyl 

Cyclohexane

2.05E-11 e1 2 CH3CH2CH2CH*CH2CH(CH2CH3)CH2CH(CH2CH3)CH2*

1-Methyl-2-HexylCyclohexane1.94E-11 e1 2 CH3CH2CH2CH2CH2CH2CH*CH2CH2CH2CH2CH*CH3

Heptyl Cyclohexane 1.91E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH2CH*CH2CH2CH2CH2CH2*

n-Tetradecane 1.79E-11 1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3

2,4,5,6,8-Pentamethyl Nonane 1.76E-11 e1 2 CH3CH(CH3)CH2CH(CH3)CH(CH3)CH(CH3)CH2CH(CH3)

CH3

2-Methyl 3,5-Diisopropyl 

Heptane

1.81E-11 e1 2,A CH3CH2CH(CH2CH(CH(CH3)CH3)CH(CH3)CH3)CH(CH3)

CH3

3,7-Dimethyl Dodecane 1.74E-11 e1 2 CH3CH2CH2CH2CH2CH(CH3)CH2CH2CH2CH(CH3)CH2CH

3

3,8-Diethyl Decane 1.82E-11 e1 2,A CH3CH2CH(CH2CH3)CH2CH2CH2CH2CH(CH2CH3)CH2CH

3

3-Methyl Tridecane 1.71E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH(CH3)CH2CH3

6-Methyl Tridecane 1.71E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH2CH(CH3)CH2CH2CH2CH2CH3

1,3-Dipropyl-5-Ethyl 

Cyclohexane

2.19E-11 e1 2 CH3CH2CH2CH*CH2CH(CH2CH3)CH2CH(CH2CH2CH3)C

H2*

trans 1-Methyl-4-Heptyl 

Cyclohexane

2.08E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH*CH2CH2CH(CH3)CH2CH2

*

Octyl Cyclohexane 2.05E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH2CH2CH*CH2CH2CH2CH2CH2

*

n-Pentadecane 2.07E-11 1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2

CH3

2,6,8-Trimethyl 4-Isopropyl 

Nonane

1.91E-11 e1 2 CH3CH(CH3)CH2CH(CH3)CH2CH(CH2CH(CH3)CH3)CH(C

H3)CH3

3,7-Dimethyl Tridecane 1.88E-11 e1 2 CH3CH2CH2CH2CH2CH2CH(CH3)CH2CH2CH2CH(CH3)CH

2CH3

3,9-Diethyl Undecane 1.96E-11 e1 2 CH3CH2CH(CH2CH3)CH2CH2CH2CH2CH2CH(CH2CH3)CH

2CH3

3-Methyl Tetradecane 1.85E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH(CH3)CH2

CH3

6-Methyl Tetradecane 1.85E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH2CH2CH(CH3)CH2CH2CH2CH2

CH3

1,3,5-Tripropyl Cyclohexane 2.33E-11 e1 2 CH3CH2CH2CH*CH2CH(CH2CH2CH3)CH2CH(CH2CH2CH3

)CH2*

1-Methyl-2-Octyl 

Cyclohexane

2.22E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH2CH2CH*CH2CH2CH2CH2CH*

CH3

Nonyl Cyclohexane 2.20E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH2CH2CH2CH*CH2CH2CH2CH2

CH2*

1,3-diethyl-5-pentyl 

cyclohexane

1.75E-11 e1 2 CH3CH2CH2CH2CH2CH*CH2CH2CH2C(CH2CH3)(CH2CH3)

CH2*

n-C16 2.32E-11 1 2,A CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2

CH2CH3

2,7-Dimethyl 3,5-Diisopropyl 

Heptane

2.09E-11 e1 2,A CH3CH(CH3)CH2CH(CH2CH(CH(CH3)CH3)CH(CH3)CH3)

CH(CH3)CH3

3-Methyl Pentadecane 2.00E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH(CH3)

CH2CH3
Table B-4 (continued)

214

Compound kOH [a] MecStructure [c] k(300) Ref [b]

4,8-Dimethyl Tetradecane 2.02E-11 e1 2 CH3CH2CH2CH2CH2CH2CH(CH3)CH2CH2CH2CH(CH3)CH

2CH2CH3

7-Methyl Pentadecane 2.00E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH(CH3)CH2CH2CH2CH2

CH2CH3

1,3-Propyl-5-Butyl 

Cyclohexane

2.47E-11 e1 2 CH3CH2CH2CH2CH*CH2CH(CH2CH2CH3)CH2CH(CH2CH2

CH3)CH2*

1-Methyl-4-Nonyl 

Cyclohexane

2.36E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH*CH2CH2CH(CH3)

CH2CH2*

Decyl Cyclohexane 2.34E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH*CH2CH2CH2

CH2CH2*

Ethene 8.15E-12 1 1

Propene 2.60E-11 1 2 CH2=CHCH3

1,2-propadiene (allene) 9.80E-12 1 3 CH2=C=CH2

1-Butene 3.11E-11 1 2 CH2=CHCH2CH3

Isobutene 5.08E-11 1 2 CH2=C(CH3)CH3

cis-2-Butene 5.58E-11 1 2 CH3^CH=CHvCH3

trans-2-Butene 6.32E-11 1 2 CH3^CH=CH^CH3

1,2-Butadiene 2.60E-11 1 3 CH2=C=CHCH3

1,3-Butadiene 6.59E-11 1 3 CH2=CHCH=CH2

1-Pentene 3.14E-11 1 2 CH2=CHCH2CH2CH3

3-Methyl-1-Butene 3.14E-11 1 2 CH2=CHCH(CH3)CH3

2-Methyl-1-Butene 6.10E-11 1 2 CH2=C(CH3)CH2CH3

2-Methyl-2-Butene 8.60E-11 1 2 CH3CH=C(CH3)CH3

cis-2-Pentene 6.50E-11 1 2 CH3^CH=CHvCH2CH3

trans-2-Pentene 6.70E-11 1 2 CH3^CH=CH^CH2CH3

Cyclopentene 6.70E-11 1 2 CH*=CHCH2CH2CH2*

Trans 1,3-Pentadiene 1.01E-10 e2 3 CH2=CH^CH=CH^CH3

1,4-Pentadiene 5.30E-11 1 3 CH2=CHCH2CH=CH2

1,2-Pentadiene 3.55E-11 1 3 CH2=C=CHCH2CH3

3-Methyl-1,2-Butadiene 5.70E-11 1 3 CH2=C=C(CH3)CH3

Isoprene 9.96E-11 1 1

1-Hexene 3.70E-11 1 2 CH2=CHCH2CH2CH2CH3

3,3-Dimethyl-1-Butene 2.80E-11 1 2 CH2=CHC(CH3)(CH3)CH3

3-Methyl-1-Pentene 3.55E-11 e1 2 CH2=CHCH(CH3)CH2CH3

4-Methyl-1-Pentene 3.55E-11 e1 2 CH2=CHCH2CH(CH3)CH3

2,3-Dimethyl-1-Butene 6.03E-11 e1 2 CH2=C(CH3)CH(CH3)CH3

2-Ethyl-1-Butene 6.01E-11 e1 2 CH2=C(CH2CH3)CH2CH3

2-Methyl-1-Pentene 6.30E-11 1 2 CH2=C(CH3)CH2CH2CH3

2,3-Dimethyl-2-Butene 1.10E-10 1 2 CH3C(CH3)=C(CH3)CH3

2-Methyl-2-Pentene 8.90E-11 1 2 CH3CH2CH=C(CH3)CH3

Cis-2-Hexene 6.60E-11 e1 2 CH3^CH=CHvCH2CH2CH3

Cis-3-Hexene 6.56E-11 e1 2 CH3CH2^CH=CHvCH2CH3

Cis-3-Methyl-2-Pentene 8.85E-11 e1 2 CH3^CH=C(^CH3)CH2CH3

Trans 3-Methyl-2-Pentene 8.85E-11 e1 2 CH3^CH=C(vCH3)CH2CH3

Trans 4-Methyl-2-Pentene 5.98E-11 4 2 CH3^CH=CH^CH(CH3)CH3

Trans-2-Hexene 6.60E-11 e1 2 CH3^CH=CH^CH2CH2CH3

Trans-3-Hexene 6.56E-11 e1 2 CH3CH2^CH=CH^CH2CH3

3-methylcyclopentene 6.67E-11 e1 2 CH3CH*CH=CHCH2CH2*

1-Methyl cyclopentene 8.96E-11 e1 2,A CH3C*=CHCH2CH2CH2*
Table B-4 (continued)

215

Compound kOH [a] MecStructure [c] k(300) Ref [b]

Cyclohexene 6.77E-11 1 2 CH*=CHCH2CH2CH2CH2*

Trans 1,4-Hexadiene 9.10E-11 1 3 CH2=CHCH2^CH=CH^CH3

1-Methyl Cyclohexene 9.40E-11 1 2 CH3C*=CHCH2CH2CH2CH2*

4-Methyl Cyclohexene 7.02E-11 e1 2 CH3CH*CH2^CH=CHvCH2CH2*

1-Heptene 4.00E-11 1 2,A CH2=CHCH2CH2CH2CH2CH3

3,4-dimethyl-1-pentene 3.69E-11 e1 2 CH2=CHCH(CH3)CH(CH3)CH3

3-methyl-1-hexene 3.69E-11 e1 2 CH2=CHCH(CH3)CH2CH2CH3

2,4-dimethyl-1-pentene 6.19E-11 e1 2,A CH2=C(CH3)CH2CH(CH3)CH3

2,3-dimethyl-1-pentene 6.19E-11 e1 2 CH2=C(CH3)CH(CH3)CH2CH3

3,3-dimethyl-1-pentene 3.33E-11 e1 2 CH2=CHC(CH3)(CH3)CH2CH3

2-methyl-1-hexene 6.19E-11 e1 2 CH2=C(CH3)CH2CH2CH2CH3

2,3,3-trimethyl-1-Butene 5.86E-11 e1 2 CH2=C(CH3)C(CH3)(CH3)CH3

4,4-dimethyl-cis-2-pentene 5.46E-11 e1 2 CH3^CH=CHvC(CH3)(CH3)CH3

2,4-dimethyl-2-pentene 8.97E-11 e1 2 CH3C(CH3)=CHCH(CH3)CH3

2-methyl-2-hexene 8.99E-11 e1 2 CH3CH2CH2CH=C(CH3)CH3

3-ethyl-2-pentene 8.95E-11 e1 2 CH3CH=C(CH2CH3)CH2CH3

3-methyl-trans-3-hexene 8.95E-11 e1 2 CH3CH2^CH=C(CH3)vCH2CH3

cis-2-heptene 6.74E-11 e1 2 CH3^CH=CHvCH2CH2CH2CH3

2-Methyl-trans-3-Hexene 6.68E-11 e1 2 CH3CH2^CH=CH^CH(CH3)CH3

3-methyl-cis-3-hexene 8.95E-11 e1 2 CH3CH2^CH=C(CH3)^CH2CH3

3,4-dimethyl-cis-2-pentene 8.97E-11 e1 2 CH3^CH=C(CH3)^CH(CH3)CH3

2,3-Dimethyl-2-Pentene 1.03E-10 1 2 CH3CH2C(CH3)=C(CH3)CH3

Cis-3-Heptene 6.70E-11 e1 2 CH3CH2^CH=CHvCH2CH2CH3

Trans 4,4-dimethyl-2-Pentene 5.50E-11 1 2 CH3^CH=CH^C(CH3)(CH3)CH3

Trans-2-Heptene 6.80E-11 1 2 CH3^CH=CH^CH2CH2CH2CH3

Trans-3-Heptene 6.70E-11 e1 2 CH3CH2^CH=CH^CH2CH2CH3

cis-3-methyl-2-hexene 8.99E-11 e1 2 CH3^CH=C(^CH3)CH2CH2CH3

trans 4-methyl-2-hexene 6.74E-11 e1 2 CH3^CH=CH^CH(CH3)CH2CH3

trans 3-methyl-2-hexene 8.99E-11 e1 2 CH3^CH=C(vCH3)CH2CH2CH3

1,2-Dimethyl Cyclohexene 1.11E-10 e1 2 CH3C*=C(CH3)CH2CH2CH2CH2*

1-Octene 3.83E-11 e1 2 CH2=CHCH2CH2CH2CH2CH2CH3

2,4,4-trimethyl-1-pentene 5.97E-11 e1 2 CH2=C(CH3)CH2C(CH3)(CH3)CH3

3-Methyl-2-Isopropyl-1-

Butene

6.25E-11 e1 2,A CH2=C(CH(CH3)CH3)CH(CH3)CH3

trans-2-octene 6.89E-11 e1 2 CH3^CH=CH^CH2CH2CH2CH2CH3

2-Methyl-2-heptene 9.13E-11 e1 2 CH3CH2CH2CH2CH=C(CH3)CH3

Cis-4-Octene 6.84E-11 e1 2,A CH3CH2CH2^CH=CHvCH2CH2CH3

Trans 2,2-Dimethyl 3-Hexene 6.50E-11 e1 2 CH3CH2^CH=CH^C(CH3)(CH3)CH3

Trans 2,5-Dimethyl 3-Hexene 6.80E-11 e1 2,A CH3CH(CH3)^CH=CH^CH(CH3)CH3

Trans-3-Octene 6.84E-11 e1 2,A CH3CH2^CH=CH^CH2CH2CH2CH3

Trans-4-Octene 6.90E-11 1 2,A CH3CH2CH2^CH=CH^CH2CH2CH3

2,4,4-trimethyl-2-Pentene 8.79E-11 e1 2 CH3C(CH3)=CHC(CH3)(CH3)CH3

2,3-dimethyl-2-hexene 1.08E-10 e1 2 CH3CH2CH2C(CH3)=C(CH3)CH3

1-Nonene 3.98E-11 e1 2 CH2=CHCH2CH2CH2CH2CH2CH2CH3

4,4-dimethyl-1-pentene 3.58E-11 e1 2 CH2=CHCH2C(CH3)(CH3)CH2CH2CH3

Trans-4-Nonene 6.98E-11 e1 2,A CH3CH2CH2^CH=CH^CH2CH2CH2CH3

1-Decene 4.12E-11 e1 2 CH2=CHCH2CH2CH2CH2CH2CH2CH2CH3

3,4-Diethyl-2-Hexene 9.39E-11 e1 2 CH3CH=C(CH2CH3)CH(CH2CH3)CH2CH3

Cis-5-Decene 7.12E-11 e1 2,A CH3CH2CH2CH2^CH=CHvCH2CH2CH2CH3
Table B-4 (continued)

216

Compound kOH [a] MecStructure [c] k(300) Ref [b]

Trans-4-Decene 7.12E-11 e1 2,A CH3CH2CH2^CH=CH^CH2CH2CH2CH2CH3

3-Carene 8.80E-11 1 3 CH3C*1=CHCH2CH*2CH(CH2*1)C*2(CH3)CH3

a-Pinene 5.18E-11 1 3 CH3C*1=CHCH2CH*2CH2CH*1C*2(CH3)CH3

b-Pinene 7.35E-11 1 3 CH2=C*1CH2CH2CH*2CH2CH*1C*2(CH3)CH3

d-Limonene 1.63E-10 1 3 CH2=C(CH3)CH*CH2CH=C(CH3)CH2CH2*

Sabinene 1.17E-10 1 3 CH2=C*1CH2CH2C*2(CH2CH*12)CH(CH3)CH3

Terpinolene 1.96E-10 e1 3 CH3C(CH3)=C*CH2CH=C(CH3)CH2CH2*

1-Undecene 4.26E-11 e1 2 CH2=CHCH2CH2CH2CH2CH2CH2CH2CH2CH3

Trans-5-Undecene 7.26E-11 e1 2,A CH3CH2CH2CH2^CH=CH^CH2CH2CH2CH2CH3

1-Dodecene 4.40E-11 e1 2 CH2=CHCH2CH2CH2CH2CH2CH2CH2CH2CH2CH3

Trans-5-Dodecene 7.40E-11 e1 2,A CH3CH2CH2CH2^CH=CH^CH2CH2CH2CH2CH2CH3

1-Tridecene 4.54E-11 e1 2 CH2=CHCH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3

Trans-5-Tridecene 7.55E-11 e1 2 CH3CH2CH2CH2^CH=CH^CH2CH2CH2CH2CH2CH2CH3

1-Tetradecene 4.69E-11 e1 2 CH2=CHCH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3

Trans-5-Tetradecene 7.69E-11 e1 2 CH3CH2CH2CH2^CH=CH^CH2CH2CH2CH2CH2CH2CH2CH

3

Trans-5-Pentadecene 7.83E-11 e1 2 CH3CH2CH2CH2^CH=CH^CH2CH2CH2CH2CH2CH2CH2CH

2CH3

Benzene 1.22E-12 1 1

Toluene 5.58E-12 1 5

Ethyl Benzene 7.00E-12 1 5

m-Xylene 2.31E-11 1 5

o-Xylene 1.36E-11 1 5

p-Xylene 1.43E-11 1 5

Styrene 5.80E-11 1 4

n-Propyl Benzene 5.80E-12 1 5

Isopropyl Benzene (cumene) 6.30E-12 1 5

m-Ethyl Toluene 1.86E-11 1 5

o-Ethyl Toluene 1.19E-11 1 5

p-Ethyl Toluene 1.18E-11 1 5

1,2,3-Trimethyl Benzene 3.27E-11 1 5

1,2,4-Trimethyl Benzene 3.25E-11 1 5

1,3,5-Trimethyl Benzene 5.67E-11 1 5

b-Methyl Styrene 5.70E-11 1 4

C10 Monosubstituted 

Benzenes

9.58E-12 e3 5

t-Butyl Benzene 4.50E-12 1 5

m-c10 disubstituted benzenes 2.55E-11 e4 5

o-c10 disubstituted benzenes 1.64E-11 e4 5

p-c10 disubstituted benzenes 1.64E-11 e4 5

1-methyl-4-isopropylbenzene 

(p-cymene)

1.45E-11 5 5

1,2,3-c10 trisubstituted 

benzenes

3.41E-11 e5 5

1,2,4-c10 trisubstituted 

benzenes

3.41E-11 e5 5
Table B-4 (continued)

217

Compound kOH [a] MecStructure [c] k(300) Ref [b]

1,3,5-c10 trisubstituted 

benzenes

5.77E-11 e5 5

Tetralin 3.40E-11 1 6

Naphthalene 2.30E-11 1 5

C11 Monosubstituted 

Benzenes

1.10E-11 e3 5

m-c11 disubstituted benzenes 2.74E-11 e4 5

o-c11 disubstituted benzenes 1.82E-11 e4 5

p-c11 disubstituted benzenes 1.82E-11 e4 5

1,2,3-c11 trisubstituted 

benzenes

3.57E-11 e5 5

1,2,4-c11 trisubstituted 

benzenes

3.57E-11 e5 5

1,3,5-c11 trisubstituted 

benzenes

5.93E-11 e5 5

Methyl Naphthalenes 1.59E-11 e6 6

C12 Monosubstituted 

Benzenes

1.24E-11 e3 5

m-c12 disubstituted benzenes 2.82E-11 e4 5

o-c12 disubstituted benzenes 1.90E-11 e4 5

p-c12 disubstituted benzenes 1.90E-11 e4 5

1,2,3-c12 trisubstituted 

benzenes

3.66E-11 e5 5

1,2,4-c12 trisubstituted 

benzenes

3.66E-11 e5 5

1,3,5-c12 trisubstituted 

benzenes

6.01E-11 e5 5

2,3-Dimethyl Naphthalene 7.68E-11 5 6

C13 Monosubstituted 

Benzenes

1.38E-11 e3 5

m-c13 disubstituted benzenes 2.96E-11 e4 5

o-c13 disubstituted benzenes 2.05E-11 e4 5

p-c13 disubstituted benzenes 2.05E-11 e4 5

1,2,3-c13 trisubstituted 

benzenes

3.81E-11 e5 5

1,2,4-c13 trisubstituted 

benzenes

3.81E-11 e5 5

1,3,5-c13 trisubstituted 

benzenes

6.17E-11 e5 5

C14 Monosubstituted 

Benzenes

1.53E-11 e3 5

m-c14 disubstituted benzenes 3.11E-11 e4 5

o-c14 disubstituted benzenes 2.19E-11 e4 5

p-c14 disubstituted benzenes 2.19E-11 e4 5

1,2,3-c14 trisubstituted 

benzenes

3.93E-11 e5 5

1,2,4-c14 trisubstituted 

benzenes

3.93E-11 e5 5
Table B-4 (continued)

218

Compound kOH [a] MecStructure [c] k(300) Ref [b]

1,3,5-c14 trisubstituted 

benzenes

6.28E-11 e5 5

C15 Monosubstituted 

Benzenes

1.67E-11 e3 5

m-c15 disubstituted benzenes 3.25E-11 e4 5

o-c15 disubstituted benzenes 2.33E-11 e4 5

p-c15 disubstituted benzenes 2.33E-11 e4 5

1,2,3-c15 trisubstituted 

benzenes

4.04E-11 e5 5

1,2,4-c15 trisubstituted 

benzenes

4.04E-11 e5 5

1,3,5-c15 trisubstituted 

benzenes

6.40E-11 e5 5

C16 Monosubstituted 

Benzenes

1.81E-11 e3 5

m-c16 disubstituted benzenes 3.39E-11 e4 5

o-c16 disubstituted benzenes 2.48E-11 e4 5

p-c16 disubstituted benzenes 2.47E-11 e4 5

1,2,3-c16 trisubstituted 

benzenes

4.17E-11 e5 5

1,2,4-c16 trisubstituted 

benzenes

4.17E-11 e5 5

1,3,5-c16 trisubstituted 

benzenes

6.52E-11 e5 5

formaldehyde 8.47E-12 1 1

methanol 9.02E-13 1 1

formic acid 4.50E-13 29 1

Ethylene Oxide 7.60E-14 20 2 CH2*CH2O*

acetaldehyde 1.49E-11 1 1

Ethanol 3.21E-12 1 2 CH3CH2OH

Dimethyl Ether 2.83E-12 1 2 CH3OCH3

glyoxal 1.10E-11 1 1

Methyl Formate 2.27E-13 19 2 CH3OCHO

acetic acid 7.26E-13 29 1

glycolaldehyde 1.49E-11 e18 24

Ethylene Glycol 1.47E-11 8 2 HOCH2CH2OH

Glycolic Acid 3.08E-12 e1 2 HOCH2C(O)OH

Acrolein 1.99E-11 20 8,A CH2=CHCHO

Trimethylene Oxide 1.03E-11 10 2 CH2*CH2OCH2*

Propylene Oxide 5.20E-13 20 2 CH3CH*CH2O*

propionaldehyde 1.97E-11 1 1

acetone 1.91E-13 1 1

Isopropyl Alcohol 5.09E-12 1 2 CH3CH(CH3)OH

n-Propyl Alcohol 5.81E-12 1 2 CH3CH2CH2OH

Acrylic Acid 2.85E-11 e1 2 CH2=CHC(O)OH

methyl glyoxal 1.50E-11 1 1

1,3-dioxolane 5.36E-11 e1 2 CH2*CH2OCH2O*

Ethyl Formate 1.02E-12 19 2 CH3CH2OCHO
Table B-4 (continued)

219

Compound kOH [a] MecStructure [c] k(300) Ref [b]

Methyl Acetate 3.49E-13 19 2 CH3C(O)OCH3

Propionic Acid 1.20E-12 29 1 CH3CH2C(O)OH

Hydroxy Acetone 3.02E-12 10 8 CH3C(O)CH2OH

Propylene Glycol 2.15E-11 8 2,A CH3CH(OH)CH2OH

Dimethoxy methane 4.90E-12 11 2,A CH3OCH2OCH3

2-Methoxyethanol 1.33E-11 10 2 CH3OCH2CH2OH

Dimethyl Carbonate 3.30E-13 11 2 CH3OC(O)OCH3

dihydroxyacetone 6.01E-12 e1 9 HOCH2C(O)CH2OH

Glycerol 1.87E-11 e1 2,A HOCH2CH(OH)CH2OH

Furan 4.02E-11 5 7

Crotonaldehyde 3.64E-11 33 8 CH3CH=CHCHO

methacrolein 2.84E-11 1 1

Cyclobutanone 8.70E-13 1 8 CH2*CH2C(O)CH2*

methylvinyl ketone 1.99E-11 1 1

Tetrahydrofuran 1.61E-11 6 2 CH2*CH2CH2OCH2*

1,2-Epoxybutane 1.91E-12 28 2 CH3CH2CH*CH2O*

2-Methylpropanal 2.68E-11 1 2 CH3CH(CH3)CHO

Butanal 2.35E-11 1 2 CH3CH2CH2CHO

methyl ethyl ketone 1.20E-12 1 1

Isobutyl Alcohol 9.30E-12 1 2 CH3CH(CH3)CH2OH

n-Butyl Alcohol 8.45E-12 1 2 CH3CH2CH2CH2OH

s-Butyl Alcohol 8.70E-12 1 2 CH3CH2CH(CH3)OH

t-Butyl Alcohol 1.07E-12 1 2 CH3C(CH3)(CH3)OH

Diethyl Ether 1.31E-11 1 2 CH3CH2OCH2CH3

gamma- butyrolactone 2.32E-12 e1 2 CH2*CH2C(O)OCH2*

Methacrylic Acid 5.24E-11 e1 2 CH2=C(CH3)C(O)OH

Methyl Acrylate 2.87E-11 e1 2 CH2=CHC(O)OCH3

Vinyl Acetate 3.16E-11 e1 2 CH2=CHOC(O)CH3

Hydroxy Methacrolein 4.30E-11 e8 8 CH2=C(CHO)CH2OH

Biacetyl 0 51 1

1,4-dioxane 3.83E-11 e1 2 CH2*CH2OCH2CH2O*

Ethyl Acetate 1.60E-12 20 2 CH3CH2OC(O)CH3

Methyl Propionate 1.03E-12 19 2 CH3CH2C(O)OCH3

n-Propyl Formate 2.38E-12 19 2 CH3CH2CH2OCHO

Isopropyl Formate 2.09E-12 e1 2 CH3CH(CH3)OCHO

isobutyric acid 2.62E-12 e1 2 CH3CH(CH3)C(O)OH

butanoic acid 4.77E-12 e1 2 CH3CH2CH2C(O)OH

Methoxy Acetone 6.77E-12 10 8 CH3C(O)CH2OCH3

1,3-Butanediol 3.32E-11 9 2 CH3CH(OH)CH2CH2OH

1,2-Butandiol 2.70E-11 9 2,A CH3CH2CH(OH)CH2OH

1,4-Butanediol 1.12E-11 e1 2 HOCH2CH2CH2CH2OH

2,3-Butanediol 2.36E-11 9 2,A CH3CH(OH)CH(CH3)OH

1-Methoxy-2-Propanol 2.00E-11 15 2,A CH3OCH2CH(CH3)OH

2-Ethoxyethanol 1.87E-11 16 2 CH3CH2OCH2CH2OH

2-Methoxy-1-Propanol 2.53E-11 e1 2 CH3OCH(CH3)CH2OH

3-methoxy-1-propanol 1.63E-11 e1 2 CH3OCH2CH2CH2OH

Propylene Carbonate 6.90E-13 24 2 CH3CH*CH2OC(O)O*

Methyl Lactate 2.76E-12 25 2 CH3OC(O)CH(CH3)OH
Table B-4 (continued)

220

Compound kOH [a] MecStructure [c] k(300) Ref [b]

Diethylene Glycol 2.75E-11 e1 2,A HOCH2CH2OCH2CH2OH

malic acid 2.28E-11 e1 2 HOC(O)CH2CH(OH)C(O)OH

2-methyl furan 6.19E-11 31 7

3-methyl furan 9.35E-11 32 7

Cyclopentanone 2.90E-12 1 8 CH2*CH2CH2C(O)CH2*

Cyclopentanol 1.10E-11 1 2 HOCH*CH2CH2CH2CH2*

Alpha-Methyltetrahydrofuran 2.20E-11 12 2 CH3CH*CH2CH2CH2O*

Tetrahydropyran 1.38E-11 10 2 CH2*CH2CH2OCH2CH2*

2-Methyl-3-Butene-2-ol 6.26E-11 30 2 CH2=CHC(CH3)(CH3)OH

2,2-Dimethylpropanal 

(pivaldehyde)

2.78E-11 1 2 CH3C(CH3)(CH3)CHO

3-Methylbutanal 

(Isovaleraldehyde)

2.70E-11 1 2 CH3CH(CH3)CH2CHO

Pentanal (Valeraldehyde) 2.78E-11 1 2 CH3CH2CH2CH2CHO

2-Pentanone 4.40E-12 1 8 CH3CH2CH2C(O)CH3

3-Pentanone 2.00E-12 1 8 CH3CH2C(O)CH2CH3

Methyl Isopropyl Ketone 3.01E-12 1 8 CH3C(O)CH(CH3)CH3

2-Pentanol 1.20E-11 1 2 CH3CH2CH2CH(CH3)OH

3-Pentanol 1.30E-11 1 2 CH3CH2CH(OH)CH2CH3

Pentyl Alcohol 1.10E-11 1 2 CH3CH2CH2CH2CH2OH

isoamyl alcohol (3-methyl-1-

butanol)

1.30E-11 1 2 CH3CH(CH3)CH2CH2OH

2-methyl-1-butanol 8.61E-12 e1 2 CH3CH2CH(CH3)CH2OH

Ethyl Isopropyl Ether 2.44E-11 e1 2 CH3CH2OCH(CH3)CH3

Methyl n-Butyl Ether 1.48E-11 6 2 CH3CH2CH2CH2OCH3

Methyl t-Butyl Ether 2.95E-12 1 2 CH3OC(CH3)(CH3)CH3

Ethyl Acrylate 3.01E-11 e1 2 CH2=CHC(O)OCH2CH3

Methyl Methacrylate 5.25E-11 e1 2 CH2=C(CH3)C(O)OCH3

Glutaraldehyde 4.16E-11 e1 2 HCOCH2CH2CH2CHO

2,4-pentanedione 7.41E-13 e1 8 CH3C(O)CH2C(O)CH3

tetrahydro-2-furanmethanol 2.77E-11 e1 2 HOCH2CH*CH2CH2CH2O*

Ethyl Propionate 2.14E-12 19 2 CH3CH2C(O)OCH2CH3

Isopropyl Acetate 3.40E-12 20 2 CH3C(O)OCH(CH3)CH3

Methyl Butyrate 3.04E-12 19 2 CH3CH2CH2C(O)OCH3

Methyl Isobutyrate 1.73E-12 21 2 CH3OC(O)CH(CH3)CH3

n-Butyl Formate 3.12E-12 19 2 CH3CH2CH2CH2OCHO

Propyl Acetate 3.40E-12 20 2 CH3CH2CH2OC(O)CH3

3-Methylbutanoic acid 8.81E-12 e1 2 CH3CH(CH3)CH2C(O)OH

2,2-Dimethoxy Propane 2.65E-12 e1 2 CH3OC(CH3)(CH3)OCH3

1-Ethoxy-2-Propanol 2.62E-11 e1 2 CH3CH2OCH2CH(CH3)OH

2-Propoxyethanol 2.47E-11 e1 2,A CH3CH2CH2OCH2CH2OH

3-Ethoxy-1-Propanol 2.20E-11 10 2 CH3CH2OCH2CH2CH2OH

3-Methoxy-1-Butanol 2.36E-11 10 2 CH3OCH(CH3)CH2CH2OH

2-Methoxyethyl Acetate 1.26E-11 e1 2 CH3C(O)OCH2CH2OCH3

Ethyl Lactate 3.91E-12 25 2 CH3CH2OC(O)CH(CH3)OH

Methyl Isopropyl Carbonate 2.55E-12 26 2 CH3OC(O)OCH(CH3)CH3

2-(2-Methoxyethoxy) Ethanol 3.41E-11 e1 2,A CH3OCH2CH2OCH2CH2OH

pentaerythritol 1.68E-11 e1 2,A HOCH2C(CH2OH)(CH2OH)CH2OH

2,5-dimethyl furan 1.32E-10 31 7
Table B-4 (continued)

221

Compound kOH [a] MecStructure [c] k(300) Ref [b]

Cyclohexanone 6.40E-12 1 9 CH2*CH2CH2C(O)CH2CH2*

Cyclohexanol 1.90E-11 1 2,A HOCH*CH2CH2CH2CH2CH2*

Hexanal 3.00E-11 1 2 CH3CH2CH2CH2CH2CHO

4-Methyl-2-Pentanone 1.27E-11 1 8 CH3C(O)CH2CH(CH3)CH3

Methyl n-Butyl Ketone 9.10E-12 1 8 CH3CH2CH2CH2C(O)CH3

Methyl t-Butyl Ketone 1.20E-12 1 8 CH3C(O)C(CH3)(CH3)CH3

1-Hexanol 1.50E-11 1 2,A CH3CH2CH2CH2CH2CH2OH

2-Hexanol 1.20E-11 1 2,A CH3CH2CH2CH2CH(CH3)OH

4-methyl-2-pentanol (methyl 

isobutyl carbinol)

1.28E-11 e1 2,A CH3CH(CH3)CH2CH(CH3)OH

Di n-Propyl Ether 1.85E-11 6 2 CH3CH2CH2OCH2CH2CH3

Ethyl n-Butyl Ether 2.13E-11 6 2 CH3CH2CH2CH2OCH2CH3

Ethyl t-Butyl Ether 8.68E-12 1 2 CH3CH2OC(CH3)(CH3)CH3

Methyl t-Amyl Ether 6.06E-12 1 2 CH3CH2C(CH3)(CH3)OCH3

diisopropyl ether 3.28E-11 e1 2 CH3CH(CH3)OCH(CH3)CH3

Ethyl Methacrylate 5.39E-11 e1 2 CH2=C(CH3)C(O)OCH2CH3

Ethyl Butyrate 4.94E-12 19 2 CH3CH2CH2C(O)OCH2CH3

Isobutyl Acetate 4.61E-12 e1 2 CH3C(O)OCH2CH(CH3)CH3

Methyl Pivalate 1.20E-12 22 2 CH3OC(O)C(CH3)(CH3)CH3

n-Butyl Acetate 4.20E-12 20 2 CH3CH2CH2CH2OC(O)CH3

n-Propyl Propionate 4.02E-12 19 2 CH3CH2CH2OC(O)CH2CH3

s-Butyl Acetate 5.50E-12 20 2 CH3CH2CH(CH3)OC(O)CH3

t-Butyl Acetate 4.25E-13 23 2 CH3C(O)OC(CH3)(CH3)CH3

Diacetone Alcohol 1.49E-12 e1 9 CH3C(O)CH2C(CH3)(CH3)OH

methyl pentanoate; methyl 

valerate

3.33E-12 e1 2 CH3CH2CH2CH2C(O)OCH3

1,2-Dihydroxy Hexane 1.87E-11 e1 2,A CH3CH2CH2CH2CH(OH)CH2OH

2-Methyl-2,4-Pentanediol 2.77E-11 9 2 CH3CH(OH)CH2C(CH3)(CH3)OH

ethylene glycol diethyl ether; 

1,2-diethoxyethane

3.51E-11 e1 2 CH3CH2OCH2CH2OCH2CH3

acetal (1,1-diethoxyethane) 1.49E-10 e1 2 CH3CH2OCH(CH3)OCH2CH3

1-Propoxy-2-Propanol 

(Propylene glycol n-propyl 

ether)

2.91E-11 e1 2,A CH3CH2CH2OCH2CH(CH3)OH

2-Butoxyethanol 2.57E-11 17 2 CH3CH2CH2CH2OCH2CH2OH

3 methoxy -3 methyl-Butanol 1.64E-11 54 23 CH3OC(CH3)(CH3)CH2CH2OH

n-propoxypropanol 2.61E-11 e1 2 CH3CH2CH2OCH2CH2CH2OH

hydroxypropyl acrylate 3.59E-11 e1 2 CH2=CHC(O)OCH2CH2CH2OH

1-Methoxy-2-Propyl Acetate 1.44E-11 7 2 CH3C(O)OCH(CH3)CH2OCH3

2-Ethoxyethyl Acetate 1.94E-11 e1 2 CH3CH2OCH2CH2OC(O)CH3

2-Methyoxy-1-propyl Acetate 2.30E-11 e1 2 CH3C(O)OCH2CH(CH3)OCH3

methoxypropanol acetate 1.40E-11 e1 2 CH3C(O)OCH2CH2CH2OCH3

2-(2-Ethoxyethoxy) Ethanol 5.08E-11 18 2 CH3CH2OCH2CH2OCH2CH2OH

Dipropylene Glycol Isomer (1-

[2-hydroxypropyl]-2-

propanol)

3.64E-11 e1 2,A CH3CH(OH)CH2OCH2CH(CH3)OH

Dimethyl Succinate 1.50E-12 27 2 CH3OC(O)CH2CH2C(O)OCH3

Ethylene Glycol Diacetate 3.78E-12 e1 2 CH3C(O)OCH2CH2OC(O)CH3

adipic acid 1.09E-11 e1 2 HOC(O)CH2CH2CH2CH2C(O)OH
Table B-4 (continued)

222

Compound kOH [a] MecStructure [c] k(300) Ref [b]

triethylene glycol 4.67E-11 e1 2 HOCH2CH2OCH2CH2OCH2CH2OH

benzaldehyde 1.20E-11 1 1

o-cresol 4.03E-11 5 1

Benzyl alcohol 2.29E-11 34 10

Methoxybenzene; Anisole 1.73E-11 32 11

Heptanal 3.00E-11 1 2 CH3CH2CH2CH2CH2CH2CHO

2-methyl-hexanal 2.54E-11 e1 2 CH3CH2CH2CH2CH(CH3)CHO

2-Heptanone 1.10E-11 1 8 CH3CH2CH2CH2CH2C(O)CH3

2-Methyl-3-Hexanone 7.21E-12 e1 8 CH3CH2CH2C(O)CH(CH3)CH3

Di-Isopropyl Ketone 5.00E-12 1 8 CH3CH(CH3)C(O)CH(CH3)CH3

5-Methyl-2-Hexanone 1.16E-11 1 8,A CH3C(O)CH2CH2CH(CH3)CH3

3-Methyl-2-Hexanone 8.23E-12 e1 8 CH3CH2CH2CH(CH3)C(O)CH3

1-Heptanol 1.40E-11 1 2 CH3CH2CH2CH2CH2CH2CH2OH

dimethylpentanol (2,3-

dimethyl-1-pentanol)

1.17E-11 e1 2 CH3CH2CH(CH3)CH(CH3)CH2OH

4,4-Dimethyl-3-oxahexane 9.63E-12 e1 2 CH3CH2OC(CH3)(CH3)CH2CH3

n-butyl acrylate 3.30E-11 e1 2 CH2=CHC(O)OCH2CH2CH2CH3

isobutyl acrylate 3.30E-11 e1 2 CH2=CHC(O)OCH2CH(CH3)CH3

Butyl Propionate 5.06E-12 e1 2 CH3CH2CH2CH2OC(O)CH2CH3

Amyl Acetate 6.05E-12 e1 2,A CH3CH2CH2CH2CH2OC(O)CH3

n-Propyl Butyrate 7.41E-12 19 2 CH3CH2CH2C(O)OCH2CH2CH3

isoamyl acetate (3-methylbutyl 

acetate)

6.03E-12 e1 2 CH3C(O)OCH2CH2CH(CH3)CH3

2-methyl-1-butyl acetate 6.31E-12 e1 2 CH3CH2CH(CH3)CH2OC(O)CH3

methyl hexanoate 4.75E-12 e1 2 CH3CH2CH2CH2CH2C(O)OCH3

1-tert-Butoxy-2-Propanol 1.87E-11 e1 2,A CH3CH(OH)CH2OC(CH3)(CH3)CH3

2-tert-Butoxy-1-Propanol 2.46E-11 e1 2 CH3CH(CH2OH)OC(CH3)(CH3)CH3

n-Butoxy-2-Propanol 

(Propylene Glycol n-Butyl 

Ether)

3.76E-11 e1 2 CH3CH2CH2CH2OCH2CH(CH3)OH

Ethyl 3-Ethoxy Propionate 1.96E-11 e1 2,A CH3CH2OCH2CH2C(O)OCH2CH3

Diisopropyl Carbonate 6.88E-12 e1 2 CH3CH(CH3)OC(O)OCH(CH3)CH3

2-(2-Propoxyethoxy) ethanol 4.38E-11 e1 2 CH3CH2CH2OCH2CH2OCH2CH2OH

Dipropylene Glycol Methyl 

Ether isomer (1-methoxy-2-[2-

hydroxypropoxy]-propane)

4.88E-11 e1 2,A CH3OCH2CH(CH3)OCH2CH(CH3)OH

Dipropylene Glycol Methyl 

Ether isomer (2-[2-

methoxypropoxy]-1-propanol)

5.48E-11 e1 2,A CH3OCH(CH3)CH2OCH(CH3)CH2OH

1,2-Propylene glycol diacetate 5.91E-12 e1 2 CH3C(O)OCH2CH(CH3)OC(O)CH3

Dimethyl Glutarate 3.50E-12 27 2,A CH3OC(O)CH2CH2CH2C(O)OCH3

2-[2-(2-Methoxyethoxy) 

ethoxy] ethanol 

5.32E-11 e1 2 CH3OCH2CH2OCH2CH2OCH2CH2OH

2-Butyl Tetrahydrofuran 2.76E-11 e1 2 CH3CH2CH2CH2CH*CH2CH2CH2O*

Octanal 2.71E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CHO

2-Octanone 1.10E-11 1 8 CH3CH2CH2CH2CH2CH2C(O)CH3

1-Octanol 1.40E-11 1 2 CH3CH2CH2CH2CH2CH2CH2CH2OH

2-Ethyl-1-Hexanol 1.33E-11 e1 2 CH3CH2CH2CH2CH(CH2CH3)CH2OH

2-Octanol 2.52E-11 7 2 CH3CH2CH2CH2CH2CH2CH(CH3)OH
Table B-4 (continued)

223

Compound kOH [a] MecStructure [c] k(300) Ref [b]

3-Octanol 3.14E-11 7 2 CH3CH2CH2CH2CH2CH(OH)CH2CH3

4-Octanol 2.87E-11 7 2,A CH3CH2CH2CH2CH(OH)CH2CH2CH3

5-methyl-1-heptanol 1.29E-11 e1 2,A CH3CH2CH(CH3)CH2CH2CH2CH2OH

Di-Isobutyl Ether 2.60E-11 13 2 CH3CH(CH3)CH2OCH2CH(CH3)CH3

Di-n-butyl Ether 2.88E-11 6 2 CH3CH2CH2CH2OCH2CH2CH2CH3

2-Phenoxyethanol; Ethylene 

glycol phenyl ether

2.99E-11 e9 11

Butyl Methacrylate 5.68E-11 e1 2 CH2=C(CH3)C(O)OCH2CH2CH2CH3

Isobutyl Methacrylate 5.68E-11 e1 2 CH2=C(CH3)C(O)OCH2CH(CH3)CH3

2,3-Dimethylbutyl Acetate 7.71E-12 e1 2 CH3C(O)OCH2CH(CH3)CH(CH3)CH3

2-Methylpentyl Acetate 7.73E-12 e1 2 CH3CH2CH2CH(CH3)CH2OC(O)CH3

3-Methylpentyl Acetate 7.73E-12 e1 2,A CH3CH2CH(CH3)CH2CH2OC(O)CH3

4-Methylpentyl Acetate 7.45E-12 e1 2 CH3C(O)OCH2CH2CH2CH(CH3)CH3

Isobutyl Isobutyrate 5.52E-12 e1 2 CH3CH(CH3)CH2OC(O)CH(CH3)CH3

n-Butyl Butyrate 1.06E-11 19 2 CH3CH2CH2CH2OC(O)CH2CH2CH3

n-Hexyl Acetate 7.47E-12 e1 2,A CH3CH2CH2CH2CH2CH2OC(O)CH3

methyl amyl acetate (4-

methyl-2-pentanol acetate)

8.16E-12 e1 2 CH3C(O)OCH(CH3)CH2CH(CH3)CH3

n-pentyl propionate 6.48E-12 e1 2,A CH3CH2CH2CH2CH2OC(O)CH2CH3

2-Ethyl Hexanoic Acid 1.33E-11 e1 2 CH3CH2CH2CH2CH(CH2CH3)C(O)OH

methyl heptanoate 6.17E-12 e1 2 CH3CH2CH2CH2CH2CH2C(O)OCH3

2-Ethyl-1,3-hexanediol 2.22E-11 e1 2,A CH3CH2CH2CH(OH)CH(CH2CH3)CH2OH

2-Hexyloxyethanol 2.89E-11 e1 2,A CH3CH2CH2CH2CH2CH2OCH2CH2OH

2,2,4-Trimethyl-1,3-

Pentanediol

1.76E-11 e1 2 CH3CH(CH3)CH(OH)C(CH3)(CH3)CH2OH

Phthalic Anhydride 4.00E-12 e10 11

2-Butoxyethyl Acetate 2.38E-11 e1 2 CH3CH2CH2CH2OCH2CH2OC(O)CH3

2-methoxy-1-(2-methoxy-1-

methylethoxy)-propane

6.13E-11 e1 2,A CH3OCH2CH(CH3)OCH2CH(CH3)OCH3

2-(2-Butoxyethoxy)-Ethanol 7.44E-11 e1 2 CH3CH2CH2CH2OCH2CH2OCH2CH2OH

dipropylene glycol ethyl ether 6.16E-11 e1 2 CH3CH2OCH(CH3)CH2OCH(CH3)CH2OH

Dimethyl Adipate 8.80E-12 27 2,A CH3OC(O)CH2CH2CH2CH2C(O)OCH3

2-(2-Ethoxyethoxy) ethyl 

acetate

3.86E-11 e1 2,A CH3CH2OCH2CH2OCH2CH2OC(O)CH3

2-[2-(2-Ethoxyethoxy) ethoxy] 

Ethanol

6.00E-11 e1 2 CH3CH2OCH2CH2OCH2CH2OCH2CH2OH

tetraethylene glycol 6.58E-11 e1 2 HOCH2CH2OCH2CH2OCH2CH2OCH2CH2OH

2-propyl cyclohexanone 1.70E-11 e1 9,A CH3CH2CH2CH*CH2CH2C(O)CH2CH2*

4-propyl cyclohexanone 1.92E-11 e1 9 CH3CH2CH2CH*CH2CH2CH2CH2CO*

1-nonene-4-one 4.04E-11 e1 9 CH2=CHCH2C(O)CH2CH2CH2CH2CH3

trimethylcyclohexanol 2.25E-11 e1 2,A CH3CH*CH2CH2CH(OH)CH(CH3)CH*CH3

2-Nonanone 1.20E-11 1 9 CH3CH2CH2CH2CH2CH2CH2C(O)CH3

Di-isobutyl ketone (2,6-

dimethyl-4-heptanone)

2.60E-11 1 9 CH3CH(CH3)CH2C(O)CH2CH(CH3)CH3

dimethylheptanol (2,6-

dimethyl-2-heptanol)

7.50E-12 e1 2 CH3CH(CH3)CH2CH2CH2C(CH3)(CH3)OH

2,6-dimethyl-4-heptanol 1.86E-11 e1 2,A CH3CH(CH3)CH2CH(OH)CH2CH(CH3)CH3

2,4-Dimethylpentyl Acetate 9.13E-12 e1 2 CH3C(O)OCH2CH(CH3)CH2CH(CH3)CH3

2-Methylhexyl Acetate 9.15E-12 e1 2,A CH3CH2CH2CH2CH(CH3)CH2OC(O)CH3
Table B-4 (continued)

224

Compound kOH [a] MecStructure [c] k(300) Ref [b]

3-Ethylpentyl Acetate 9.56E-12 e1 2 CH3CH2CH(CH2CH3)CH2CH2OC(O)CH3

3-Methylhexyl Acetate 9.15E-12 e1 2 CH3CH2CH2CH(CH3)CH2CH2OC(O)CH3

4-Methylhexyl Acetate 9.15E-12 e1 2 CH3CH2CH(CH3)CH2CH2CH2OC(O)CH3

5-Methylhexyl Acetate 8.87E-12 e1 2,A CH3C(O)OCH2CH2CH2CH2CH(CH3)CH3

Isoamyl Isobutyrate 6.94E-12 e1 2 CH3CH(CH3)CH2CH2OC(O)CH(CH3)CH3

n-Heptyl Acetate 8.89E-12 e1 2 CH3CH2CH2CH2CH2CH2CH2OC(O)CH3

methyl octanoate 7.59E-12 e1 2 CH3CH2CH2CH2CH2CH2CH2C(O)OCH3

1-(butoxyethoxy)-2-propanol 4.97E-11 e1 2,A CH3CH2CH2CH2OCH2CH2OCH2CH(CH3)OH

Dipropylene glycol n-propyl 

ether isomer #1

5.86E-11 e1 2,A CH3CH2CH2OCH2CH(CH3)OCH2CH(CH3)OH

Dipropylene glycol methyl 

ether acetate isomer #1

4.42E-11 e1 2,A CH3C(O)OCH(CH3)CH2OCH(CH3)CH2OCH3

Dipropylene glycol methyl 

ether acetate isomer #2

4.42E-11 e1 2,A CH3C(O)OCH(CH3)CH2OCH2CH(CH3)OCH3

2-[2-(2-Propoxyethoxy) 

ethoxy] Ethanol

6.30E-11 e1 2 CH3CH2CH2OCH2CH2OCH2CH2OCH2CH2OH

tripropylene glycol 6.59E-11 e1 2 CH3CH(OH)CH2OCH2CH(CH3)OCH2CH(CH3)OH

2,5,8,11-Tetraoxatridecan-13-

ol

7.24E-11 e1 2 CH3OCH2CH2OCH2CH2OCH2CH2OCH2CH2OH

glyceryl triacetate 8.49E-12 e1 2 CH3C(O)OCH2CH(CH2OC(O)CH3)OC(O)CH3

Camphor 4.60E-12 e1 9 CH3C*1(CH3)CH*2CH2CH2C*1(CH3)C(O)CH2*2

a-terpineol 9.51E-11 e1 2 CH3C*=CHCH2CH(CH2CH2*)C(CH3)(CH3)OH

Citronellol (3,7-dimethy-6-

octen-1-ol)

9.87E-11 e1 2 CH3C(CH3)=CHCH2CH2CH(CH3)CH2CH2OH

Hydroxycitronellal 2.80E-11 e1 2 CH3CH(CH2CHO)CH2CH2CH2C(CH3)(CH3)OH

menthol 2.40E-11 e1 2 CH3CH(CH3)CH*CH2CH2CH(CH3)CH2CH*OH

Linalool 1.22E-10 e1 3 CH2=CHC(CH3)(OH)CH2CH2CH=C(CH3)CH3

2-Decanone 1.30E-11 1 9,A CH3CH2CH2CH2CH2CH2CH2CH2C(O)CH3

8-Methyl-1-Nonanol (Isodecyl 

Alcohol)

1.54E-11 e1 2 CH3CH(CH3)CH2CH2CH2CH2CH2CH2CH2OH

1-decanol 1.55E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2OH

3,7-dimethyl-1-octanol 1.57E-11 e1 2 CH3CH(CH3)CH2CH2CH2CH(CH3)CH2CH2OH

Di-n-Pentyl Ether 3.47E-11 14 2,A CH3CH2CH2CH2CH2OCH2CH2CH2CH2CH3

1,2-Diacetyl benzene 4.00E-12 35 11

2,4-Dimethylhexyl Acetate 1.08E-11 e1 2,A CH3CH2CH(CH3)CH2CH(CH3)CH2OC(O)CH3

2-Ethyl-Hexyl Acetate 1.10E-11 e1 2,A CH3CH2CH2CH2CH(CH2CH3)CH2OC(O)CH3

3,4-Dimethylhexyl Acetate 1.08E-11 e1 2,A CH3CH2CH(CH3)CH(CH3)CH2CH2OC(O)CH3

3,5-Dimethylhexyl Acetate 1.06E-11 e1 2 CH3C(O)OCH2CH2CH(CH3)CH2CH(CH3)CH3

3-Ethylhexyl Acetate 1.10E-11 e1 2 CH3CH2CH2CH(CH2CH3)CH2CH2OC(O)CH3

3-Methylheptyl Aceate 1.06E-11 e1 2 CH3CH2CH2CH2CH(CH3)CH2CH2OC(O)CH3

4,5-Dimethylhexyl Acetate 1.06E-11 e1 2,A CH3C(O)OCH2CH2CH2CH(CH3)CH(CH3)CH3

4-Methylheptyl Acetate 1.06E-11 e1 2 CH3CH2CH2CH(CH3)CH2CH2CH2OC(O)CH3

5-Methylheptyl Aceate 1.06E-11 e1 2,A CH3CH2CH(CH3)CH2CH2CH2CH2OC(O)CH3

n-Octyl Acetate 1.03E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2OC(O)CH3

Geraniol 1.80E-10 e1 3 CH3C(CH3)=CHCH2CH2C(CH3)=CHCH2OH

methyl nonanoate 9.01E-12 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2C(O)OCH3

2-(2-Ethylhexyloxy) Ethanol 3.24E-11 e1 2,A CH3CH2CH2CH2CH(CH2CH3)CH2OCH2CH2OH

2-(2-Hexyloxyethoxy) Ethanol 4.81E-11 e1 2,A CH3CH2CH2CH2CH2CH2OCH2CH2OCH2CH2OH
Table B-4 (continued)

225

Compound kOH [a] MecStructure [c] k(300) Ref [b]

glycol ether dpnb {1-(2-

butoxy-1-methylethoxy)-2-

propanol}

6.00E-11 e1 2,A CH3CH2CH2CH2OCH2CH(CH3)OCH2CH(CH3)OH

2-(2-Butoxyethoxy) ethyl 

acetate

4.29E-11 e1 2 CH3CH2CH2CH2OCH2CH2OCH2CH2OC(O)CH3

2-[2-(2-Butoxyethoxy) 

ethoxy] Ethanol

6.44E-11 e1 2 CH3CH2CH2CH2OCH2CH2OCH2CH2OCH2CH2OH

Tripropylene Glycol 

Monomethyl Ether

7.83E-11 e1 2 CH3OCH2CH(CH3)OCH2CH(CH3)OCH2CH(CH3)OH

2-Ethyl-Hexyl Acrylate 3.94E-11 e1 2 CH2=CHC(O)OCH2CH(CH2CH3)CH2CH2CH2CH3

2,3,5-Teimethylhexyl Acetate 1.22E-11 e1 2,A CH3C(O)OCH2CH(CH3)CH(CH3)CH2CH(CH3)CH3

2,3-Dimethylheptyl Acetate 1.23E-11 e1 2 CH3CH2CH2CH2CH(CH3)CH(CH3)CH2OC(O)CH3

2,4-Dimethylheptyl Acetate 1.23E-11 e1 2,A CH3CH2CH2CH(CH3)CH2CH(CH3)CH2OC(O)CH3

2,5-Dimethylheptyl Acetate 1.23E-11 e1 2 CH3CH2CH(CH3)CH2CH2CH(CH3)CH2OC(O)CH3

2-Methyloctyl Acetate 1.20E-11 e1 2,A CH3CH2CH2CH2CH2CH2CH(CH3)CH2OC(O)CH3

3,5-Dimethylheptyl Acetate 1.23E-11 e1 2,A CH3CH2CH(CH3)CH2CH(CH3)CH2CH2OC(O)CH3

3,6-Dimethylheptyl Acetate 1.20E-11 e1 2 CH3C(O)OCH2CH2CH(CH3)CH2CH2CH(CH3)CH3

3-Ethylheptyl Acetate 1.24E-11 e1 2 CH3CH2CH2CH2CH(CH2CH3)CH2CH2OC(O)CH3

4,5-Dimethylheptyl Acetate 1.23E-11 e1 2,A CH3CH2CH(CH3)CH(CH3)CH2CH2CH2OC(O)CH3

4,6-Dimethylheptyl Acetate 1.20E-11 e1 2 CH3C(O)OCH2CH2CH2CH(CH3)CH2CH(CH3)CH3

4-Methyloctyl Acetate 1.20E-11 e1 2 CH3CH2CH2CH2CH(CH3)CH2CH2CH2OC(O)CH3

5-Methyloctyl Acetate 1.20E-11 e1 2,A CH3CH2CH2CH(CH3)CH2CH2CH2CH2OC(O)CH3

n-Nonyl Acetate 1.17E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2OC(O)CH3

methyl decanoate 1.04E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH3

2,6,8-trimethyl-4-nonanone; 

Isobutyl heptyl ketone

2.31E-11 e1 9 CH3CH(CH3)CH2C(O)CH2CH(CH3)CH2CH(CH3)CH3

Trimethylnonanolthreoerythro; 

2,6,8-Trimethyl-4-nonanol

2.32E-11 e1 2,A CH3CH(CH3)CH2CH(CH3)CH2CH(OH)CH2CH(CH3)CH3

3,6-Dimethyloctyl Acetate 1.37E-11 e1 2 CH3CH2CH(CH3)CH2CH2CH(CH3)CH2CH2OC(O)CH3

3-Isopropylheptyl Acetate 1.38E-11 e1 2,A CH3CH2CH2CH2CH(CH2CH2OC(O)CH3)CH(CH3)CH3

4,6-Dimethyloctyl Acetate 1.37E-11 e1 2 CH3CH2CH(CH3)CH2CH(CH3)CH2CH2CH2OC(O)CH3

methyl undecanoate 1.19E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH3

1-Hydroxy-2,2,4-

Trimethylpentyl-3-Isobutyrate

1.29E-11 e1 2 CH3CH(CH3)C(O)OCH(CH(CH3)CH3)C(CH3)(CH3)CH2OH

3-Hydroxy-2,2,4-

Trimethylpentyl-1-Isobutyrate

1.62E-11 e1 2,A CH3CH(CH3)C(O)OCH2C(CH3)(CH3)CH(OH)CH(CH3)CH3

diethylene glycol mono(2-

ethylhexyl) ether

5.16E-11 e1 2 CH3CH2CH2CH2CH(CH2CH3)CH2OCH2CH2OCH2CH2OH

Diethyl Phthalate 5.67E-12 e11 11

Dimethyl Sebacate 9.69E-12 e1 2 CH3OC(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH3

diisopropyl adipate 1.04E-11 e1 2 CH3CH(CH3)OC(O)CH2CH2CH2CH2C(O)OCH(CH3)CH3

3,6,9,12-Tetraoxahexadecan1-ol8.35E-11 e1 2,A CH3CH2CH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2O

H

triethyl citrate 5.91E-12 e1 2 CH3CH2OC(O)CH2C(OH)(CH2C(O)OCH2CH3)C(O)OCH2C

H3

3,5,7-Trimethyloctyl Acetate 1.51E-11 e1 2,A CH3C(O)OCH2CH2CH(CH3)CH2CH(CH3)CH2CH(CH3)CH3

3-Ethyl-6-Methyloctyl Acetate 1.55E-11 e1 2,A CH3CH2CH(CH3)CH2CH2CH(CH2CH3)CH2CH2OC(O)CH3

4,7-Dimethylnonyl Acetate 1.51E-11 e1 2,A CH3CH2CH(CH3)CH2CH2CH(CH3)CH2CH2CH2OC(O)CH3

methyl dodecanoate {methyl 

laurate}

1.33E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH3
Table B-4 (continued)

226

Compound kOH [a] MecStructure [c] k(300) Ref [b]

tripropylene glycol n-butyl 

ether

9.54E-11 e1 2 CH3CH2CH2CH2OCH2CH(CH3)OCH2CH(CH3)OCH(CH3)C

H2OH

2,3,5,7-Tetramethyloctyl 

Acetate

1.68E-11 e1 2 CH3C(O)OCH2CH(CH3)CH(CH3)CH2CH(CH3)CH2CH(CH3

)CH3

3,5,7-Trimethylnonyl Acetate 1.68E-11 e1 2,A CH3CH2CH(CH3)CH2CH(CH3)CH2CH(CH3)CH2CH2OC(O)

CH3

3,6,8-Trimethylnonyl Acetate 1.65E-11 e1 2,A CH3C(O)OCH2CH2CH(CH3)CH2CH2CH(CH3)CH2CH(CH3)

CH3

methyl tridecanoate 1.47E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OC

H3

2-ethylhexyl benzoate 1.37E-11 e12 11

2,4,6,8-Tetramethylnonyl 

Acetate

1.82E-11 e1 2,A CH3C(O)OCH2CH(CH3)CH2CH(CH3)CH2CH(CH3)CH2CH(

CH3)CH3

3-Ethyl-6,7-Dimethylnonyl 

Acetate

1.86E-11 e1 2,A CH3CH2CH(CH2CH2OC(O)CH3)CH2CH2CH(CH3)CH(CH3)

CH2CH3

4,7,9-Trimethyldecyl Acetate 1.79E-11 e1 2,A CH3C(O)OCH2CH2CH2CH(CH3)CH2CH2CH(CH3)CH2CH(

CH3)CH3

methyl myristate {methyl 

tetradecanoate}

1.61E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)

OCH3

methyl cis-9-pentadecenoate 7.76E-11 e1 2 CH3CH2CH2CH2CH2CH=CHCH2CH2CH2CH2CH2CH2CH2

C(O)OCH3

methyl pentadecanoate 2.10E-11 e1 2 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2

C(O)CH3

2,3,5,6,8-Pentaamethylnonyl 

Acetate

1.99E-11 e1 2 CH3C(O)OCH2CH(CH3)CH(CH3)CH2CH(CH3)CH(CH3)CH

2CH(CH3)CH3

3,5,7,9-Tetramethyldecyl 

Acetate

1.96E-11 e1 2,A CH3C(O)OCH2CH2CH(CH3)CH2CH(CH3)CH2CH(CH3)CH2

CH(CH3)CH3

5-Ethyl-3,6,8-Trimethylnonyl 

Acetate

2.00E-11 e1 2,A CH3CH2CH(CH2CH(CH3)CH2CH2OC(O)CH3)CH(CH3)CH2

CH(CH3)CH3

Dibutyl phthalate 8.59E-12 e11 11

2,2,4-trimethyl-1,3-

pentanediol diisobutyrate

1.15E-11 e1 2 CH3CH(CH3)C(O)OCH2C(CH3)(CH3)CH(OC(O)CH(CH3)C

H3)CH(CH3)CH3

methyl linolenate; methyl 

cis,cis,cis-9,12,15-

octadecatrienoate

2.02E-10 e1 2 CH3CH2^CH=CHvCH2^CH=CHvCH2^CH=CHvCH2CH2C

H2CH2CH2CH2CH2C(O)OCH3

methyl linoelate; methyl 

cis,cis-9,12-octadecadienoate

1.42E-10 e1 2 CH3CH2CH2CH2CH2^CH=CHvCH2^CH=CHvCH2CH2CH2

CH2CH2CH2CH2C(O)OCH3

Methylamine 1.97E-11 38 3,12 CH3NH2

Methyl Chloride 4.48E-14 6 3 CH3Cl

Methyl nitrite 1.20E-13 20 13

nitromethane 1.30E-13 6 26

Carbon disulfide 2.76E-12 48 19

Dichloromethane 1.45E-13 20 3 ClCH2Cl

Methyl Bromide 4.12E-14 20 17

Chloroform 1.06E-13 20 3 ClCH(Cl)Cl

methyl iodide 1.03E-13 29 20 CH3I

Chloropicrin 0 51 18

Acetylene 7.56E-13 6 1

Dimethyl Amine 6.52E-11 38 3,12 CH3NHCH3
Table B-4 (continued)

227

Compound kOH [a] MecStructure [c] k(300) Ref [b]

Ethyl Amine 2.58E-11 38 3,12 CH3CH2NH2

Ethanolamine 4.41E-11 e14 3,12 NH2CH2CH2OH

Vinyl Chloride 6.90E-12 6 3 CH2=CHCl

Ethyl Chloride 4.18E-13 6 3 CH3CH2Cl

1,1-difluoroethane; HFC-152a 3.47E-14 55 28

Methyl isothiocyanate 1.72E-12 49 19

nitroethane 1.50E-13 6 27

Dimethyl Sulfoxide 6.20E-11 20 19

Chloroacetaldehyde 3.10E-12 47 1

1,1-Dichloroethene 1.09E-11 2 3 CH2=C(Cl)Cl

Trans-1,2-Dichloroethene 2.32E-12 6 3 ClCH=CH^Cl

1,1-Dichloroethane 2.60E-13 20 3 CH3CH(Cl)Cl

1,2-Dichloroethane 2.53E-13 6 3 ClCH2CH2Cl

1,1,1,2-tetrafluoroethane; 

HFC-134a

4.59E-15 55 29

Ethyl Bromide 3.08E-13 20 17

Trichloroethylene 2.34E-12 6 3 ClCH=C(Cl)Cl

1,1,1-Trichloroethane 1.24E-14 20 3 CH3C(Cl)(Cl)Cl

1,1,2-Trichloroethane 2.00E-13 6 3 ClCH2CH(Cl)Cl

Perchloroethylene 1.71E-13 6 3 ClC(Cl)=C(Cl)Cl

1,2-Dibromoethane 2.27E-13 6 17

Methyl Acetylene 5.90E-12 6 2 HC#CCH3

Acrylonitrile 4.90E-12 42 14

Trimethyl Amine 4.84E-11 38 3,12 CH3N(CH3)CH3

isopropylamine 3.78E-11 e14 3,12 CH3CH(CH3)NH2

1-amino-2-propanol 4.85E-11 e1 3,12 CH3CH(OH)CH2NH2

3-Chloropropene 3.20E-11 e1 3 CH2=CHCH2Cl

1-nitropropane 1.33E-12 e1 3 CH3CH2CH2NO2

2-nitropropane 2.57E-13 58 27

chloroacetone 0 51 1

trans-1,3-dichloropropene 1.44E-11 45 3 Cl^CH=CH^CH2Cl

cis-1,3-dichloropropene 8.45E-12 45 3 Cl^CH=CHvCH2Cl

1,2-Dichloropropane 4.50E-13 e1 3 CH3CH(Cl)CH2Cl

trans 1,3,3,3-

tetrafluoropropene 

9.25E-13 52 21

2,3,3,3-tetrafluoropropene 1.05E-12 53 22

n-Propyl Bromide 1.18E-12 44 17

1,1,1,3,3-pentafluoropropane 7.24E-15 55 30

3,3-dichloro-1,1,1,2,2-

pentafluoropropane;HCFC225ca

2.57E-14 55 31

1,3-dichloro-1,1,2,2,3-

pentafluoropropane;HCFC225cb

9.11E-15 55 31

1,3-butadiyne 2.13E-11 e7 36

2-Butyne 2.72E-11 6 2 CH3C#CCH3

Ethyl Acetylene 8.00E-12 6 2 HC#CCH2CH3

t-butyl amine 1.18E-11 39 3,12 CH3C(CH3)(CH3)NH2
Table B-4 (continued)

228

Compound kOH [a] MecStructure [c] k(300) Ref [b]

morpholine 1.12E-10 e1 2 CH2*CH2OCH2CH2NH*

ethyl methyl ketone oxime 5.14E-12 e15 15 CH3CH2C(CH3)=NOH

Dimethylaminoethanol 6.85E-11 40 3,12 CH3N(CH3)CH2CH2OH

2-amino-1-butanol 5.32E-11 e14 3,12 CH3CH2CH(NH2)CH2OH

2-Amino-2-Methyl-1-Propanol 2.80E-11 41 3,12 CH3C(CH3)(NH2)CH2OH

1-Chlorobutane 2.19E-12 e1 3 CH3CH2CH2CH2Cl

Diethanol Amine 1.01E-10 e14 3,12 HOCH2CH2NHCH2CH2OH

2-(Cl-methyl)-3-Cl-Propene 3.16E-11 2 3 CH2=C(CH2Cl)CH2Cl

n-Butyl Bromide 2.46E-12 44 17

1,1,1,3,3-pentafluorobutane; 

HFC-365mfc

7.12E-15 55 32

2-amino-2-ethyl-1,3-

propanediol

2.70E-11 e1 3,12 CH3CH2C(NH2)(CH2OH)CH2OH

N-Methyl-2-Pyrrolidone 2.15E-11 43 16

methyl nonafluorobutyl ether 1.15E-12 e1 3 CH3OC(F)(F)C(F)(F)C(F)(F)C(F)(F)F

methoxy-perfluoro-n-butane 1.20E-14 57 35

1,1,1,2,2,3,4,5,5,5-

decafluoropentane; HFC-43-

10mee

3.50E-15 55 33

Triethyl Amine 5.57E-11 e14 3,12 CH3CH2N(CH2CH3)CH2CH3

Monochlorobenzene 7.70E-13 20 11

Nitrobenzene 1.41E-13 5 11

p-Dichlorobenzene 5.55E-13 e16 11

Triethanolamine 8.04E-11 e14 3,12 HOCH2CH2N(CH2CH2OH)CH2CH2OH

Hexamethyldisiloxane 1.38E-12 20 11

Hydroxymethyldisiloxane 1.89E-12 20 11

Hexafluorobenzene 1.74E-13 6 11

ethoxy-perfluoro-n-butane 6.40E-14 56 34

ethoxy-perfluoro-isobutane 7.70E-14 56 34

ethyl nonafluorobutyl ether 7.97E-12 e1 3 CH3CH2OC(F)(F)C(F)(F)C(F)(F)C(F)(F)F

m-Nitrotoluene 1.24E-12 5 11

Benzotrifluoride 4.60E-13 46 11

p-Trifluoromethyl-Cl-Benzene 2.40E-13 46 11

Para Toluene Isocyanate 5.90E-12 36 6

D4 Cyclosiloxane 1.00E-12 20 11

2,4-Toluene Diisocyanate 7.40E-12 37 6

Molinate 2.42E-11 e17 19

Ethyl di-n-PropylThiolcarbamate 2.12E-11 50 19

triisopropanolamine 9.37E-11 e14 3,12 CH3CH(OH)CH2N(CH2CH(CH3)OH)CH2CH(CH3)OH

Pebulate 2.26E-11 e17 19

D5 Cyclosiloxane 1.55E-12 20 11

thiobencarb 1.87E-11 e17 19

Methylene Diphenylene 

Diisocyanate

1.18E-11 e13 6

PROD2 Species #1 9.63E-12 e1 8 CH3C(O)CH2CH2CH2OH

PROD2 Species #2 1.45E-11 e1 8 CH3C(O)CH2CH(CH3)CH2OH
Table B-4 (continued)

229

Compound kOH [a] MecStructure [c] k(300) Ref [b]

PROD2 Species #3 1.52E-11 e1 8 CH3CH2C(O)CH2CH2CH(CH3)OH

PROD2 Species #4 1.83E-11 e1 8 CH3CH2C(O)CH2CH2CH(OH)CH2CH3

PROD2 Species #5 1.97E-11 e1 8 CH3CH2CH2CH(OH)CH2CH2C(O)CH2CH3

RNO3 Species #1 1.60E-12 e1 8 CH3CH2CH(CH3)ONO2

RNO3 Species #2 1.15E-11 e1 8 CH3CH(OH)CH2CH2CH2ONO2

RNO3 Species #3 4.70E-12 e1 8 CH3CH2CH(CH3)CH(CH3)ONO2

RNO3 Species #4 9.89E-12 e1 8 CH3CH2CH2CH2CH2CH(ONO2)CH2OH

RNO3 Species #5 5.64E-12 e1 8 CH3CH2C(CH3)(ONO2)CH2CH(CH3)CH3

RNO3 Species #6 9.87E-12 e1 8 CH3CH2CH2CH2CH2CH2CH2CH(ONO2)CH2CH3

[a] Rate constant for reaction with OH radicals at 300oK in units of cm3 molec-1s

-1

. See the complete mechanism 

listing in the electronic version of the report for the temperature dependences, where available. Footnotes for 

measured rate constants are as follows:

1 As recommended or tabulated by Atkinson and Arey (2003)

2 Atkinson (1997) Recommendation

3 Carter et al (2000a)

4 298K Rate constant as recommended by Calvert et al (2000). Temperature dependence estimated from 

k(T)=A exp(500/T), where A is adjusted to yield the recommended 298K rate constant, based on data for 

those alkenes for which temperature dependence data are available.

5 As recommended or tabulated by Calvert et al (2002)

6 Rate constant expression recommended by Atkinson (1994)

7 Carter et al (2000b).

8 Aschmann and Atkinson (1998).

9 Bethel et al, (2001).

10 Dagaut et al (1989)

11 Rate constant used is average of various measurements tabulated by Sidebottom et al (1997).

12 Wallington et al (1990).

13 Bennett and Kerr (1989).

14 Wallington et al (1988a).

15 Average of values of Porter et al (1995) and Aschmann and Atkinson (1998)

16 Rate constant of Dagaut et al (1988a) used. Value of Hartmann et al (1986) is not consistent with chamber 

data (Carter et al, 1993)

17 Average of values of Dagaut et al (1988a), Stemmler et al (1996) and Aschmann and Atkinson (1998).

18 Carter et al (1993).

19 Wallington et al (1988b).

20 Rate constant expression recommended by Atkinson (1989). Recommendation not changed in evaluation 

updates.

21 Wyatt et al. (1999).

22 Wallington et al (2001)

23 Smith et al (1992). Average of values relative to propane and n-butane

24 Carter et al (1996b).

25 Atkinson and Carter (1995).

26 Carter et al (2000c)

27 Carter et al (1997c).

28 Wallington et al (1988c).

29 IUPAC (2006) Recommendation

30 Rudich et al (1995), as recommended by Atkinson (personal communication, 2000). Good agreement with 

data of Ferronato et al (1998).

31 Bierbach et al (1992)

32 Atkinson et al (1989)

33 Atkinson et al (1983).

34 As tabulated by Atkinson (1989) (Cited reference not available).
Table B-4 (continued)

230

35 Wang et al (2006).

36 Carter et al (1999a)

37 Becker et al (1988).

38 Average of values tabulated by Carl and Crowley (1998).

39 Koch et al (1996)

40 Average of values of Harris and Pitts (1983) and Anderson and Stephens (1988), as tabulated by Atkinson 

(1989).

41 Harris and Pitts (1983)

42 Harris et al (1981). Rate constant is pressure dependent and was measured at lower than atmospheric 

pressures, and extrapolated to atmospheric pressure.

43 Aschmann and Atkinson (1999).

44 Donaghy et al. (1993).

45 Tuazon et al (1988).

46 Atkinson et al (1985).

47 Rate constants from Scollard et al (1993)

48 Mechanism is complex and depends on pressure, temperature, and O2 content. Rate constant given is for 1 

atm air and 298oK only, and derived from the IUPAC (2006) rate constants recommended for CS2 and 

HOCS2 (the species assumed to be initially formed in the reaction). See Carter and Malkina (2007).

49 Rate constant from Carter and Malkina (2007).

50 Rate constant from Carter and Malkina (2007). This is somewhat higher than the value determined by

Kwok et al (1992), but is used as the basis for evaluating the mechanism against chamber data.

51 Reaction expected to be slow and is neglected.

52 Søndergaard et al (2007)

53 Nielsen et al (2007)

54 Carter et al (2010)

55 NASA (2006) recommendation.

56 Christensen et al (1998)

57 Wallington et al (1997). Rate constant for mixture of isomers, which couldn't be separated.

58 Liu et al (1990)

Footnotes for estimated rate constants are as follows:

e1 Estimated using the group-additivity estimation assignments implemented in the current mechanism 

generation system. See Carter (2000a) and Table 3.

e2 Assumed to have the same rate constant as the cis isomer.

e3 Rate constant estimated using rate constant for ring addition for toluene, derived based on the observed 

benzaldehyde + belzyl nitrate yields, and estimated rate constants for abstraction reactions for additions at 

various positions of the molecules of the mixture of alkylbenzenes used to represent those with this carbon 

number. Partial rate constant for reaction at the -CH2- group next to the aromatic derived from the rate 

constant for ethylbenzene and the ring addition rate constant for toluene. Partial rate constants for reactions 

at other positions based on standard structure-reactivity methods used in the mechanism generation system. 

(Carter, 2000a). The compounds used to represent the lumped monoalkylbenzenes are given with the 

aromatics mechanism documentation.

e4 Rate constant estimated using the estimated rate constants for ring addition for the xylene isomers, derived 

based on the observed tolualdenyde yields and estimated nitrate yields, and based on estimated rate 

constants for abstraction reactions for additions at various positions of the molecules of the mixture of 

alkylbenzenes used to represent those with this carbon number. Separate ring addition estimates are made 

for o-, m-, and p-configurations. Partial rate constant for reaction at the -CH2- or -CH- groups next to the 

aromatic derived from the rate constants for ethylbenzene or isopropyl benzene, respectively and the ring 

addition rate constant for toluene. Partial rate constants for reactions at other positions based on standard 

structure-reactivity methods used in the mechanism generation system. (Carter, 2000a). The compounds 

used to represent the lumped dialkylbenzenes are given in Table 10.

e5 Rate constant estimated using the estimated rate constants for ring addition for the trimethylbenzene 

isomers, derived based on the observed aromatic aldehyde yields and estimated nitrate yields, and based on 

estimated rate constants for abstraction reactions for additions at various positions of the molecules of the 

mixture of alkylbenzenes used to represent those with this carbon number. Separate estimates are made for 

1,2,3 (3CnnBEN3), 1,3,4 (4CnnBEN3) and 1,3,5 (5CnnBEN3) substituent configurations, based on the 
Table B-4 (continued)

231

trimethylbenzenes. (Aromatic aldehyde yields for 1,2,3-trimethylbenzene are not available. The ring 

addition rate constant for this compound is estimated to be the same as that for 1,2,4-trimethylbenzene.) 

Partial rate constant for reaction at the -CH2- or -CH- groups next to the aromatic derived from the rate 

constants for ethylbenzene or isopropyl benzene, respectively, and the ring addition rate constant for 

toluene. Partial rate constants for reactions at other positions based on standard structure-reactivity methods 

used in the mechanism generation system (Carter, 2000a). The compounds used to represent the lumped 

trialkylbenzenes are given in are given in Table 10.

e6 Average of rate constants for 1-methyl and 2-methyl naphthalenes

e7 Estimated to have a similar rate constant as 2-butyne, on the basis of the fact that the rate constant for 1,3-

butadiene is similar to that for the 2-butenes. This estimate is highly uncertain.

e8 Rate constant estimated by Carter and Atkinson (1996).

e9 Rate constant for reaction at the aromatic ring assumed to be the same as that for anisole. Rate constant for 

reaction at the anisole aromatic ring estimated from the total OH rate constant and the rate constant for 

reaction at methoxy group estimated using the structure-reactivity estimation methods used in the 

mechanism generation system (Carter, 2000). Rate constants for reactions at other positions in this 

molecule also estimated using the structure-reactivity estimation methods used in the mechanism 

generation system (Carter, 2000).

e10 Estimated to have the same rate constant as 1,2-diacetyl pthallate on the basis of similar substitution around 

the aromatic ring, and the expectation that for both compound the reaction would be primarily at the 

aromatic ring.

e11 Rate constant for reaction at the aromatic ring assumed to be the same as measured for 1,2-diacetyl 

phthalate. Rate constant for reaction at groups off the aromatic ring estimated using the group-additivity 

methods incorporated in the mechanism generation system (Carter, 2000).

e12 Rate constant for reaction at the aromatic ring estimated to be the same as the total rate constant for 

acetophenone (Atkinson, 1989), assuming that ring addition is the major reaction for that compound. The 

rate constant for reaction at groups off the aromatic ring based on those estimated for 2-ethyl hexyl acetate, 

since reaction at the acetate group is estimated to be negligible for that compound.

e13 Estimated to have a rate constant that it twice that of pare-toluene isocyanate, based on the structure of the 

molecule (Carter et al, 1999a).

e14 Derived from structure-reactivity methods, where group rate constants for reactions at HN, NH2, at groups 

adjacent to the amino group were derived based on rate constants for the simple amines for which rate 

constant data are available.

e15 The rate constant for addition of OH to the C=N double bond is estimated by the rate constant for OH + 

isobutene x the average of the ratio of the rate constants for CH2=NOH / Ethene and CH3CH=NOH / 

Propene, with abstractions from the methyl group subtracted off. The CH2=NOH and CH3CH=NOH rate 

constants are from the tabulation of Atkinson (1989). The rate constants for addition to the methyl groups 

were estimated using the structure-reactivity methods incorporated in the mechanism generation system.

e16 Average of values for o-, m- and p- isomers tabulated by Atkinson (1989).

e17 Rate constant as estimated by Carter and Malkina (2007).

e18 Assumed to have the same rate constant as acetaldehyde.

[b] Codes for types of mechanisms that were derived are as follows. See the complete mechanism listing Table B-2

of this report for the mechanisms.

1 Reactions in the base mechanism or the base chlorine mechanism. See Table A-2 or Table A-5 for 

documentation.

2 Mechanism derived using the mechanism generation system. Rate constants and branching ratios may have 

been assigned based on available data or estimates for individual cases. See documentation of the 

mechanism generation system. In most cases these mechanisms should be the same as or similar to those in 

SAPRC-99.

3 Mechanism derived using the mechanism generation system using enhanced capabilities and additional 

assignments that were developed for this project. Rate constants and branching ratios may have been 

assigned based on available data or estimates for individual cases. See documentation of the mechanism 

generation system. Note that these mechanisms could not be generated using the SAPRC-99 version of the 

mechanism generation system. 
Table B-4 (continued)

232

4 The styrene mechanism is based on that derived by Carter et al, (1999b) except for some rate constants 

updates and re-adjustment of the nitrate yields based on the chamber data. Mechanisms for other styrenes 

were estimated based on that developed for styrene.

5 The mechanisms for alkylbenzenes were derived as discussed in the documentation of the updated 

aromatics mechanism. The general ring opening mechanism is as shown on Figure 2.

6 The mechanism for this aromatic compound is a simplified and parameterized representation that was 

either adjusted to fit chamber data or was derived based on mechanism(s) adjusted to fit chamber data. See 

Table 14 on non-alkylbenzene aromatics for further information.

7 The furans are assumed to react primarily to form the monounsaturated 1,4-dicarbonyl resulting from OH 

addition adjacent to the oxygen, followed by ring opening. These were represented by the AFG1 and 

AFG2 model species with their relative yields adjusted to fit available chamber data where such data are 

available, as used in the general aromatic hydrocarbon mechanism discussed in the text.

8 Portions of the mechanism for this photoreactive compound were derived using the mechanism generation 

system, with appropriate assignments for rate constants and branching ratios as applicable. The photolysis 

reactions were estimated, with absorption cross-sections and quantum yields derived as indicated on Table 

A-3 or A-6. The mechanism generation system is described by Carter (2000a), with updates and extensions 

as described by in the text.

9 Photolysis reactions of C9+ ketones are assumed to be negligible, based on the apparent decline in overall 

quantum yields with carbon number in mechanisms that give the best fits to environmental chamber data. 

The mechanisms for the other reactions are estimated using the mechanism generation system.

10 The benzyl alcohol mechanism is based on that derived by Carter et al (2005a). The measured 

benzaldehyde in the chamber experiments are consistent with a fraction reacted by abstraction from the -

CH2OH of 30%, and the products formed following the addition to the aromatic ring are assumed to be the 

same as used for ethylbenzene. The nitrate yield factor derived for toluene for the peroxy reactions 

involved in the ring addition mechanism gives results in reasonably good fits to the data and was not 

adjusted.

11 The mechanism for this aromatic compound was derived by analogy to the reactions of benzene or the 

alkylbenzenes. See text for more details.

12 See Carter (2008a) for a discussion of the mechanisms for the amines and the associated uncertainties and 

evaluation problems. The magnitudes of the calculated atmospheric reactivities must be considered to be 

upper limits because of the possibility of removal of the amines by reaction with atmospheric nitric acid is 

assumed to be negligible in the calculations, which might not be the case. The evaluations against chamber 

data is uncertain because the amount of amine present in the gas phase at the beginning of the chamber 

experiments could not be determined, and are expected to be lower than the calculated amounts reacted 

because of the tendency of the amines to go to surfaces. The amount of initially present amine in the 

experiments had to be adjusted to fit the initial rates of NO oxidation in the experiments, and the adjusted 

amounts were always less than the calculated amount injected.

13 The reaction with OH is assumed to proceed by abstraction from the methyl group, followed by 

decomposition to form NO and formaldehyde. The photolysis absorption cross sections are from Calvert 

and Pitts (1966). The major reaction pathway is photolysis, which is assumed to form methyl radicals and 

NO with unit quantum yields.

14 The data of Hashimoto et al (1984) indicate that the products are formaldehyde and HCO-CN after an NO 

to NO2 conversion. HCO-CN is assumed to be relatively unreactive, which is supported by the 

concentration-time profiles reported by Hashimoto et al (1984). Reactions with NO3 and O3 are assumed to 

be relatively slow, though no data are available concerning these reactions.

15 An estimated mechanism was derived explicitly for this compound. About 24% of the reaction is assumed 

to occur at the methyl or CH2 groups, with the subsequent reactions estimated using the procedures in the 

mechanism generation system. The remainder of the reaction is assumed to be addition of OH to the C=N 

double bond, which is assumed to form primarily C2H2C(CH3)(OH)N(.)OH, which is assumed to react 

with O2 to form C2H5C(CH3)(OH)NO + HO2. The rate constant is estimated by the rate constant for OH + 

isobutene x the average of the ratio of the rate constants for CH2=NOH / Ethene and CH3CH=NOH / 

Propene, with abstractions from the methyl group subtracted off. The CH2=NOH and CH3CH=NOH rate 

constants are from the tabulation of Atkinson (1989). The C2H5C(CH3)(OH)NO is assumed to photolyze 

rapidly, forming NO + an alpha-hydroxy radical that reacts with O2 to form MEK and HO2. The absorption 
Table B-4 (continued)

233

cross-sections and quantum yields are unknown, but photolysis is assumed to be relatively rapid, and 

estimated to be comparable to that of methyl nitrite.

16 The N-methyl 2-pyrrolidone mechanism is based on that derived by Carter et al (1996b).

17 The mechanism for bromine-containing compound were derived based on that estimated using the 

mechanism generation system for the corresponding chlorine-containing compound, but using the 

appropriate rate constant for the individual compound. The mechanisms were not optimized to fit the 

chamber data and no mechanisms were found to simulate the data particularly well (Carter and Tuazon, 

2000).

18 The mechanism for chloropicrin is based on that of Carter et al (1997b), updated as discussed by Carter and 

Malkina (2007).

19 The mechanisms for these pesticide compounds were derived as discussed by Carter and Malkina (2007), 

but updated to the current version of the mechanism.

20 The mechanism used for methyl iodide, including the reactions of the inorganic iodine species formed, is 

given by Carter (2007).

21 The mechanism, and its evaluation against chamber data, is documented by Carter (2009a).

22 The mechanism, and its evaluation against chamber data, is documented by Carter (2009b).

23 The mechanism, and its evaluation against chamber data, is documented by Carter et al (2010).

24 Assumed to have an analogous mechanism as that for acetaldehyde, except that the absorption crosssections and quantum yields are those recommended by IUPAC (2006) for glycolaldehyde.

26 Mechanism estimated for this compound based on the following assumptions. Mechanism assumed to 

involve formation of CH3N(OH)(O)O, which thermally decomposes to HNO3 + CH3. Pressure dependence 

and rate constants for other nitro compounds suggest that H-abstraction not important for alpha-nitro 

compounds.

27 Mechanism estimated for this compound based on the following assumptions. Reaction at group not 

adjacent to the nitro group, followed by O2 reaction with the alkoxy radical formed assumed to dominate. 

Nitrate formation ignored. HCOCH2NO2 represented by Acetaldehyde + XN, and CH3CH(NO2)CHO 

represented by RCHO + XN.

28 Mechanism estimated for this compound based on the following assumptions. Reaction assumed to occur at 

the CH3 group, followed by reaction of the alkoxy radical formed with O2, forming CHF2CHO. The latter is 

represented by acetaldehyde (which probably overestimates its reactivity).

29 Mechanism estimated for this compound based on the following assumptions. Decomposition of alkoxy 

radical, forming CF3 and inert F2CO assumed. CF3O assumed to react with other VOCs to form CF3OH, 

which is treated as inert. The effect of the CF3O + VOC reaction is represented by the formation of OH.

30 Mechanism estimated for this compound based on the following assumptions. Overall nitrate yield 

estimated by assuming it is the same as the alkyl peroxy radical with the same number of carbons. Products 

formed assumed to be unreactive. Reaction of alkoxy radical with O2 assumed to dominate.

31 Mechanism estimated for this compound based on the following assumptions. Overall nitrate yield 

estimated by assuming it is the same as the alkyl peroxy radical with the same number of carbons. Products 

formed assumed to be unreactive. Decomposition to form chlorine atoms assumed to dominate.

32 Mechanism estimated for this compound based on the following assumptions. Most of reaction is assumed 

to occur at CH2 group, with the alkoxy radical formed assumed to react with O2 to form a relatively 

unreactive fluorinated carbonyl product. Overall nitrate yield estimated by assuming it is the same as the 

alkyl peroxy radical with the same number of carbons.

33 Mechanism estimated for this compound based on the following assumptions. Alkoxy radical formed 

following abstraction from either hydrogen is assumed to decompose forming an alpha-hydrogensubstituted radical that reacts to form an alkoxy radical that reacts with O2 forming HO2 and an unreactive 

carbonyl fluoride. Nitrate yields in peroxy radical reactions assumed to be the same as in the corresponding 

alkylperoxy radical with the same number of carbons.

34 Mechanism estimated for this compound based on the following assumptions. Reaction assumed to occur 

primarily at the CH2 group, ultimately giving rise to methyl radicals and C4F9OCHO, which is assumed to 

be unreactive. Nitrate yield from peroxy radical formed assumed to be the same as that formed from ethyl 

propyl ether.

35 Mechanism estimated for this compound based on the following assumptions. Alkoxy radical formed 

assumed to react with O2 forming HO2 and a perfluoro formate, which is assumed to be unreactive. Nitrate 

yield from peroxy radical formed assumed to be the same as that formed from ethyl propyl ether.
Table B-4 (continued)

234

36 It is assumed that the primary reaction is OH or NO3 adding to terminal position, forming an allylicstabilized radical. In the case of the OH reaction, the 1,2-unsaturated alpha-hydroxy radical reacts with O2

to form HO2 and 1,2-butadien-4-al, and in the case of the NO3 reaction the analogous compound reacts 

unimolecularly to form NO2 and the same aldehyde. The aldehyde is represented by RCHO, on the basis 

that this is probably not as bad an approximation as MACR. It is assumed that the reaction with O3 is slow. 

A The atmospheric reactivity values were derived using the "Adjusted Products" version of the mechanism, 

where the major oxidation products are represented explicitly using mechanisms derived using the 

mechanism generation system. See Carter (2000a, 2009) for more details concerning how adjusted products 

mechanisms are derived.

LM This compound is represented using the "lumped molecule" approach, where the atmospheric reactivity of 

this compound is assumed to have the same per-molecule atmospheric impact as another compound. See 

Table B-9 for the compounds used to represent other compounds using the lumped molecule approach.

[c] Structures used when deriving the mechanism using the mechanism generation system. If no structure is given 

then the mechanism generation system was not used to derive the mechanisms. "*", "*1", "*2" indicate join 

points for cyclic or bicyclic compounds. "^" and "v" are used to indicate cis/trans isomerization for alkenes 

(cis/trans isomerization for cyclic compounds isn't recognized by the system). "#" indicates a triple bond.
235

Table B-5. Listing of compounds for which mechanisms have been derived. 2. Rate constants for 

reactions with O3, NO3, and O3P at 300oK, where applicable.

Compound Rate constant at 300 K (cm3 molec-1

s

-1

) [a]

O3 NO3 O

3

P

Propene 1.05E-17 1 9.73E-15 1 4.01E-12 2

1-Butene 9.08E-18 1 1.38E-14 1 4.17E-12 2

Isobutene 1.17E-17 1 3.44E-13 1 1.68E-11 2

cis-2-Butene 1.28E-16 1 3.52E-13 1 1.75E-11 2

trans-2-Butene 1.95E-16 1 3.93E-13 1 1.99E-11 2

1,3-Butadiene 6.64E-18 1 1.00E-13 1 1.98E-11 2

1-Pentene 1.10E-17 1 1.50E-14 1 4.69E-12 2

3-Methyl-1-Butene 9.87E-18 3 1.39E-14 e1 4.19E-12 2

2-Methyl-1-Butene 1.48E-17 1 3.32E-13 e1 1.80E-11 2

2-Methyl-2-Butene 4.11E-16 1 9.37E-12 1 5.08E-11 2

cis-2-Pentene 1.31E-16 1 3.70E-13 e1 1.70E-11 2

trans-2-Pentene 1.63E-16 1 3.70E-13 e1 2.10E-11 2

Cyclopentene 5.61E-16 1 4.20E-13 1 2.10E-11 2

Trans 1,3-Pentadiene 1.33E-17 e2 5.69E-13 e1 4.76E-11 e3

1,4-Pentadiene 1.51E-17 3 2.76E-14 e1 1.41E-11 e3

Isoprene 1.34E-17 1 6.81E-13 1 3.50E-11 2

1-Hexene 1.17E-17 1 1.80E-14 1 5.03E-12 2

3,3-Dimethyl-1-Butene 4.08E-18 3 1.38E-14 e1 4.80E-12 2

3-Methyl-1-Pentene 3.97E-18 3 1.39E-14 e1 5.60E-12 e1

4-Methyl-1-Pentene 1.04E-17 3 1.39E-14 e1 5.60E-12 e1

2,3-Dimethyl-1-Butene 1.04E-17 4 3.32E-13 e1 1.73E-11 e1

2-Ethyl-1-Butene 1.35E-17 4 4.52E-13 1 1.73E-11 e1

2-Methyl-1-Pentene 1.66E-17 4 3.32E-13 e1 2.03E-11 e1

2,3-Dimethyl-2-Butene 1.14E-15 1 5.72E-11 1 7.64E-11 2

2-Methyl-2-Pentene 3.48E-16 e1 9.37E-12 e1 3.86E-11 e1

Cis-2-Hexene 1.08E-16 1 3.70E-13 e1 2.05E-11 e1

Cis-3-Hexene 1.43E-16 6 3.70E-13 e1 2.05E-11 e1

Cis-3-Methyl-2-Pentene 4.58E-16 7 9.37E-12 e1 3.71E-11 e1

Trans 3-Methyl-2-Pentene 5.69E-16 7 9.37E-12 e1 3.71E-11 e1

Trans 4-Methyl-2-Pentene 1.15E-16 e1 3.70E-13 e1 1.84E-11 e1

Trans-2-Hexene 1.57E-16 1 3.70E-13 e1 2.05E-11 e1

Trans-3-Hexene 1.64E-16 8 3.70E-13 e1 2.05E-11 e1

3-methylcyclopentene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

1-Methyl cyclopentene 6.81E-16 10 9.37E-12 e1 3.71E-11 e1

Cyclohexene 8.30E-17 1 5.10E-13 1 2.00E-11 2

Trans 1,4-Hexadiene 1.69E-16 e4 3.84E-13 e1 3.91E-11 e3

1-Methyl Cyclohexene 1.64E-16 1 1.00E-11 1 9.00E-11 11

4-Methyl Cyclohexene 9.04E-17 1 3.70E-13 e1 2.05E-11 e1

1-Heptene 1.21E-17 1 2.00E-14 1 8.70E-12 e1

3,4-dimethyl-1-pentene 1.01E-17 e1 1.40E-14 e1 5.60E-12 e1

3-methyl-1-hexene 1.01E-17 e1 1.40E-14 e1 5.60E-12 e1

2,4-dimethyl-1-pentene 1.18E-17 e1 3.32E-13 e1 1.73E-11 e1

2,3-dimethyl-1-pentene 1.18E-17 e1 3.32E-13 e1 1.73E-11 e1

3,3-dimethyl-1-pentene 1.01E-17 e1 1.38E-14 e1 5.60E-12 e1

2-methyl-1-hexene 1.18E-17 e1 3.32E-13 e1 1.73E-11 e1

2,3,3-trimethyl-1-Butene 8.09E-18 4 3.32E-13 e1 1.73E-11 e1
Table B-5 (continued)

236

Compound Rate constant at 300 K (cm3 molec-1

s

-1

) [a]

O3 NO3 O

3

P

4,4-dimethyl-cis-2-pentene 1.15E-16 e1 3.70E-13 e1 1.55E-11 e1

2,4-dimethyl-2-pentene 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

2-methyl-2-hexene 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

3-ethyl-2-pentene 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

3-methyl-trans-3-hexene 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

cis-2-heptene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

2-Methyl-trans-3-Hexene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

3-methyl-cis-3-hexene 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

3,4-dimethyl-cis-2-pentene 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

2,3-Dimethyl-2-Pentene 6.74E-16 e1 5.72E-11 e1 5.07E-11 e1

Cis-3-Heptene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

Trans 4,4-dimethyl-2-Pentene 1.15E-16 e1 3.70E-13 e1 1.57E-11 e1

Trans-2-Heptene 1.15E-16 e1 3.70E-13 e1 2.34E-11 e1

Trans-3-Heptene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

cis-3-methyl-2-hexene 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

trans-4-methyl-2-hexene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

trans-3-methyl-2-hexene 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

1,2-Dimethyl Cyclohexene 2.11E-16 12 5.72E-11 e1 5.29E-11 e1

1-Octene 1.45E-17 3 1.39E-14 e1 5.60E-12 e1

2,4,4-trimethyl-1-pentene 1.18E-17 e1 3.32E-13 e1 1.73E-11 e1

3-Methyl-2-Isopropyl-1-Butene 3.45E-18 5 3.32E-13 e1 1.73E-11 e1

trans-2-octene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

2-Methyl-2-heptene 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

Cis-4-Octene 9.22E-17 6 3.70E-13 e1 2.05E-11 e1

Trans 2,2-Dimethyl 3-Hexene 4.34E-17 9 3.70E-13 e1 2.05E-11 e1

Trans 2,5-Dimethyl 3-Hexene 4.24E-17 9 3.70E-13 e1 2.05E-11 e1

Trans-3-Octene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

Trans-4-Octene 1.34E-16 8 3.70E-13 e1 2.40E-11 e1

2,4,4-trimethyl-2-Pentene 1.44E-16 10 9.37E-12 e1 3.71E-11 e1

2,3-dimethyl-2-hexene 6.74E-16 e1 5.72E-11 e1 5.29E-11 e1

1-Nonene 1.01E-17 e1 1.39E-14 e1 5.60E-12 e1

4,4-dimethyl-1-pentene 1.01E-17 e1 1.39E-14 e1 5.60E-12 e1

Trans-4-Nonene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

1-Decene 9.68E-18 3 1.40E-14 e1 5.60E-12 e1

3,4-Diethyl-2-Hexene 4.28E-18 7 9.37E-12 e1 3.71E-11 e1

Cis-5-Decene 1.13E-16 6 3.70E-13 e1 2.05E-11 e1

Trans-4-Decene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

3-Carene 3.76E-17 13 9.10E-12 1 3.20E-11 2

a-Pinene 8.55E-17 1 6.09E-12 1 3.20E-11 2

b-Pinene 1.57E-17 1 2.51E-12 1 2.70E-11 2

d-Limonene 2.17E-16 1 1.22E-11 1 7.20E-11 2

Sabinene 8.40E-17 13 1.00E-11 1 6.27E-11 e3

Terpinolene 1.02E-15 e1 6.66E-11 e1 1.63E-10 e1

1-Undecene 1.01E-17 e1 1.40E-14 e1 5.60E-12 e1

Trans-5-Undecene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

1-Dodecene 1.01E-17 e1 1.40E-14 e1 5.60E-12 e1

Trans-5-Dodecene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

1-Tridecene 1.01E-17 e1 1.41E-14 e1 5.60E-12 e1
Table B-5 (continued)

237

Compound Rate constant at 300 K (cm3 molec-1

s

-1

) [a]

O3 NO3 O

3

P

Trans-5-Tridecene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

1-Tetradecene 1.01E-17 e1 1.41E-14 e1 5.60E-12 e1

Trans-5-Tetradecene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

Trans-5-Pentadecene 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

Styrene 1.76E-17 3 1.50E-13 1 1.75E-11 e5

b-Methyl Styrene 3.25E-16 e6 3.92E-13 e7 1.62E-11 e3

Glyoxal 1.02E-15 e8

glycolaldehyde 2.84E-15 e17

Acrolein 3.07E-19 17 1.18E-15 18 2.37E-12 e1

Acrylic Acid 1.01E-17 e1 2.76E-18 e1 4.60E-12 e1

Methyl Glyoxal 2.53E-15 e8

Crotonaldehyde 1.58E-18 19 5.12E-15 20 7.29E-12 e1

Methacrolein 1.28E-18 1 3.54E-15 1 6.34E-12 e8

Methylvinyl ketone 5.36E-18 1 4.32E-12 e8

2-Methylpropanal 1.15E-14 1

Butanal 1.15E-14 1

Methacrylic Acid 1.18E-17 e1 6.71E-17 e1 1.42E-11 e1

Methyl Acrylate 1.01E-17 e1 2.76E-18 e1 4.60E-12 e1

Vinyl Acetate 1.01E-17 e1 1.38E-14 e1 5.60E-12 e1

Hydroxy Methacrolein 1.28E-18 e9 3.40E-15 e10 9.95E-12 e1

2-Methyl-3-Butene-2-ol 9.68E-18 15 1.21E-14 16 2.01E-11 e1

2,2-Dimethylpropanal (pivaldehyde) 2.40E-14 1

3-Methylbutanal (Isovaleraldehyde) 1.90E-14 1

Pentanal (Valeraldehyde) 1.50E-14 1

Ethyl Acrylate 1.01E-17 e1 3.70E-18 e1 4.60E-12 e1

Methyl Methacrylate 1.18E-17 e1 6.71E-17 e1 1.42E-11 e1

Glutaraldehyde 7.63E-15 e1

Hexanal 1.60E-14 1

Ethyl Methacrylate 1.18E-17 e1 6.80E-17 e1 1.42E-11 e1

hydroxypropyl acrylate 1.01E-17 e1 2.96E-17 e1 4.60E-12 e1

Benzaldehyde 2.73E-15 21

o-Cresol 1.40E-11 2

Heptanal 1.90E-14 1

2-methyl-hexanal 3.90E-15 e1

n-butyl acrylate 1.01E-17 e1 5.06E-17 e1 4.60E-12 e1

isobutyl acrylate 1.01E-17 e1 1.14E-16 e1 4.60E-12 e1

Octanal 1.70E-14 1

Butyl Methacrylate 1.18E-17 e1 1.15E-16 e1 1.42E-11 e1

Isobutyl Methacrylate 1.18E-17 e1 1.79E-16 e1 1.42E-11 e1

a-terpineol 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

Citronellol (3,7-dimethy-6-octen-1-ol) 3.48E-16 e1 9.37E-12 e1 3.71E-11 e1

Hydroxycitronellal 4.03E-15 e1

Linalool 3.58E-16 e1 9.38E-12 e1 6.60E-11 e1

Geraniol 6.96E-16 e1 1.87E-11 e1 1.35E-10 e1

2-Ethyl-Hexyl Acrylate 1.01E-17 e1 2.95E-16 e1 4.60E-12 e1

methyl cis-9-pentadecenoate 1.15E-16 e1 3.70E-13 e1 2.05E-11 e1

methyl linolenate (methyl cis,cis,cis-9,12,15-

octadecatrienoate)

3.45E-16 e1 1.11E-12 e1 1.59E-10 e1
Table B-5 (continued)

238

Compound Rate constant at 300 K (cm3 molec-1

s

-1

) [a]

O3 NO3 O

3

P

methyl linoelate (methyl cis,cis-9,12-

octadecadienoate)

2.30E-16 e1 7.40E-13 e1 7.47E-11 e1

Methylamine 7.40E-21 22 9.60E-14 e11

Acetylene 1.16E-20 14

Dimethyl Amine 1.67E-18 22 2.03E-13 e11

Ethyl Amine 2.09E-20 e12 1.16E-13 e11

Ethanolamine 6.86E-20 e12 1.35E-13 e11

Dimethyl Sulfoxide 3.00E-13 27

Trichloroethylene 2.99E-16 18 4.37E-14 e1

Trimethyl Amine 7.84E-18 22 1.56E-13 e11

isopropylamine 3.48E-20 e12 1.21E-13 e11

1-amino-2-propanol 6.58E-20 e18 1.35E-13 e1

trans-1,3-dichloropropene 7.12E-19 24 9.13E-17 e13 1.30E-12 e14

cis-1,3-dichloropropene 1.60E-19 25 5.57E-18 e13 4.79E-13 e14

1,3-butadiyne 1.00E-15 e7

t-butyl amine 0 e12 5.88E-14 e11

morpholine 3.77E-18 e18 3.30E-13 e1

Dimethylaminoethanol 6.76E-18 22 1.80E-13 e11

2-amino-1-butanol 3.74E-19 e12 1.70E-13 e11

2-Amino-2-Methyl-1-Propanol 0 e12 5.88E-14 e11

Diethanol Amine 3.78E-18 e12 3.30E-13 e11

2-(Cl-methyl)-3-Cl-Propene 4.14E-19 26 1.00E-15 e15 5.60E-12 e1

2-amino-2-ethyl-1,3-propanediol 5.89E-14 e1

N-Methyl-2-Pyrrolidone 1.26E-13 23

Triethyl Amine 1.20E-17 e12 1.71E-13 e11

Triethanolamine 3.94E-17 e12 2.29E-13 e11

Molinate 9.20E-15 e16

EPTC (S-Ethyl Dipropylthiocarbamate) 9.20E-15 28

triisopropanolamine 3.94E-17 e12 2.29E-13 e11

Pebulate 9.20E-15 e16

Thiobencarb 9.20E-15 e16

[a] See the complete mechanism listing in the electronic version of the report for the temperature dependences, 

where available. Footnotes for measured rate constants are as follows:

1 As recommended or tabulated by Atkinson and Arey (2003)

2 As recommended or tabulated by Calvert et al (2002)

3 Rate constant at 298K as recommended or tabulated by Atkinson and Arey (2003). Temperature 

dependence estimated by assuming that the A factor is the same as that for 1 butene.

4 Rate constant at 298K as recommended or tabulated by Atkinson and Arey (2003). Temperature 

dependence estimated by assuming that the A factor is the same as that for 2 methyl-1-butene.

5 T=298K rate constant recommended by Atkinson (1997). Temperature dependence estimated by assuming 

the A factor is the same as for isobutene.

6 Rate constant at 298K as recommended or tabulated by Atkinson and Arey (2003). Temperature 

dependence estimated by assuming that the A factor is the same as that for cis-2-butene.

7 Rate constant at 298K as recommended by Atkinson (1997). Temperature dependence estimated by 

assuming that the A factor is the same as that for 2-methyl-1-butene.

8 Rate constant at 298K as recommended or tabulated by Atkinson and Arey (2003). Temperature 

dependence estimated by assuming that the A factor is the same as that for trans-2-butene.
Table B-5 (continued)

239

9 Rate constant at 298K as recommended by Atkinson (1997). Temperature dependence estimated by 

assuming that the A factor is the same as that for trans-2-butene.

10 Rate constant at 298K as recommended or tabulated by Atkinson and Arey (2003). Temperature 

dependence estimated by assuming that the A factor is the same as that for 2-methyl-2-butene.

11 Atkinson (1997) Recommendation

12 Rate constant at 298K as recommended by Atkinson (1997). Temperature dependence estimated by 

assuming that the A factor is the same as that for 2,3-dimethyl-2-butene.

13 Rate constant at 298K as recommended or tabulated by Atkinson and Arey (2003). Temperature 

dependence estimated by assuming that the A factor is the same as that for alpha-pinene.

14 Rate constant at 298K recommended by IUPAC (2006). A factor estimated to be approximately 2 times 

that for ethene, as assumed by Carter (2000a).

15 Rate constant at 298K is average of 291K rate constant of Grosjean and Grosjean (1994) and the 298K rate 

constant of Fantechi et al (1998). Temperature dependence estimated by assuming that the A factor is the 

same as that for 1-butene

16 Rate expression of Rudich et al (1996), as recommended by Atkinson (private communication, 2000). 

Reasonable agreement with data of Fantechi et al (1998).

17 Rate constant at 298K recommended by Atkinson (1994). Temperature dependence estimated by assuming 

that the A factor is the same as that for methacrolein.

18 Rate constant relative to ethene from Atkinson et al (1987). Placed on an absolute basis using 300K rate 

constant for ethene recommended by Atkinson and Arey (2003).

19 Sato et al (2004b).

20 Rate constant relative to propene from Atkinson et al (1987). Placed on an absolute basis using 300K rate

constant for propene recommended by Atkinson and Arey (2003).

21 The T=298K rate constant recommended by Atkinson (1994). Temperature dependence estimated by 

assuming the reaction has the same A factor as the reaction of NO3 with acetaldehyde. This gives the same 

298K rate constant but a slightly different temperature dependence than used in SAPRC-99.

22 Rate constant from Tuazon et al (1994)

23 Rate constant from Aschmann and Atkinson (1999)

24 Rate constant at 298K from Tuazon et al (1984). Temperature dependence estimated by assuming that the 

A factor is the same as that for trans-2-butene.

25 Rate constant at 298K from Tuazon et al (1984). Temperature dependence estimated by assuming that the 

A factor is the same as that for cis-2-butene.

26 Rate constant at 298K from Atkinson and Carter (1984). Temperature dependence estimated by assuming 

that the A factor is the same as that for isobutene.

27 Rate constant is geometric mean of measurements of Barnes et al (1989) and Falbe-Hansen et al (2000), as 

used by Carter et al (2000).

28 Rate constant from Kwok et al (1992)

Footnotes for estimated rate constants are as follows:

e1 Estimated using the group-additivity estimation assignments implemented in the current mechanism 

generation system. See Carter (2000a).

e2 Rate constant unknown. Roughly estimate that it is similar to that for isoprene

e3 Estimated from correlation between measured OH and O3P rate constants (with ethene, allene, and some 

other outliers excluded) at 300K.

e4 Estimated as the sum of the 300K rate constants for 1-hexene and trans-2-hexene.

e5 Assumed to have the same rate constant as cis-2-butene on the basis of their having similar OH radical rate 

constants.

e6 Estimated from the 300K styrene, propene, and trans-2-butene rate constants by assuming that the 

styrene/b-methyl styrene ratio is the same as the ratio for propene to trans-2-butene.

e7 Estimated from the correlation between OH and NO3 rate constants, using the assigned 300K OH rate 

constant for this compound.

e8 Estimated value used in SAPRC-99 mechanism. See base mechanism listing and Carter (2000a).

e9 Estimated to have the same rate constant and kinetic parameters as methacrolein, as assumed by Carter and 

Atkinson (1996).

e10 Rate constant assumed to be the same as for methacrolein (Carter and Atkinson, 1996)
Table B-5 (continued)

240

e11 Estimated based on the NO3 + NMP rate constant and assuming ratios of rate constants for reactions of 

NO3 at various types of amine groups is the same as those estimated for the reactions of OH with those 

groups. Reaction assumed to occur only from NH or NH2 or from C-H bonds on carbons bonded to the 

amino group.

e12 Estimated from the estimated rate of reaction of OH at the alpha position, and correlations between this and 

the measured O3 rate constants of Tuazon et al (1994) for the methylamines and DMAE. Reaction assumed 

to be slow if no abstractable hydrogens in a group adjacent to the amino group.

e13 Estimated by Carter and Malkina (2007) based on correlation between O3 and NO3 rate constants.

e14 Estimated by Carter and Malkina (2007) based on correlation between O3 and NO3 rate constants.

e15 This rate constant estimated by Atkinson (private communication, 1997) based on the rate constant for NO3

+ Allyl chloride (Atkinson, 1991)

e16 Estimated by Carter and Malkina (2007) to have the same rate constant as EPTC.

e17 Assumed to have the same rate constant as acetaldehyde.

e18 Estimated from estimated rate of reaction of OH at the alpha position, and correlations between this and the 

measured O3 rate constants of Tuazon et al (1994) for the methylamines and DMAE.
241

Table B-6. Listing of compounds for which mechanisms have been derived. 3. Absorption crosssections, quantum yields, and mechanisms for photolysis reactions, where applicable.

Compound Phot Data [a] Mechanism

glycolaldehyde HOCCHO 6 GLCLALD + HV = CO + #2 HO2 + HCHO

Acrolein MACR-06 e2 ACROLEIN + HV = #.178 OH + #1.066 HO2 + #.234 MEO2 + 

#.33 MACO3 + #1.188 CO + #.102 CO2 + #.34 HCHO + #.05 

CCOOH + #-.284 XC

Hydroxy Acetone MEK-06 0.175 e3 HOACET + HV = HO2 + MECO3 + HCHO

Crotonaldehyde MACR-06 e2 CROTALD + HV = #2 HO2 + #2 CO + CCHO

2-Methylpropanal C2CHO e1 2MEC3AL + HV = HO2 + #.96 RO2C + #.04 RO2XC + #.04 

zRNO3 + CO + #.96 xHO2 + #.96 xACET + yROOH + #-.12 

XC

Butanal C2CHO e1 1C4RCHO + HV = HO2 + #.98 RO2C + #.02 RO2XC + #.02 

zRNO3 + CO + #.98 xHO2 + #.98 xRCHO + yROOH + #-.06 

XC

Hydroxy Methacrolein MACR-06 e2 HOMACR + HV = HO2 + RCO3 + CO + HCHO + #-1 XC

Methoxy Acetone MEK-06 0.1 e3 MEOACET + HV = MECO3 + RO2C + xHO2 + #.079 

xHCHO + yROOH + #1.921 XC

2,2-Dimethylpropanal 

(pivaldehyde)

C2CHO e1 22DMC3AL + HV = HO2 + #.961 RO2C + #.039 RO2XC + 

#.039 zRNO3 + CO + #.961 xTBUO + yR6OOH + #-.079 XC

3-Methylbutanal 

(Isovaleraldehyde)

C2CHO e1 3MC4RCHO + HV = HO2 + #1.294 RO2C + #.053 RO2XC + 

#.053 zRNO3 + CO + #.947 xHO2 + #.348 xHCHO + #.613 

xRCHO + #.334 xACET + yR6OOH + #.492 XC

Pentanal 

(Valeraldehyde)

C2CHO e1 1C5RCHO + HV = HO2 + #1.686 RO2C + #.069 RO2XC + 

#.069 zRNO3 + CO + #.931 xHO2 + #.931 xRCHO + 

yR6OOH + #.792 XC

2-Pentanone MEK-06 0.1 e3 MPK + HV = MECO3 + #.98 RO2C + #.02 RO2XC + #.02 

zRNO3 + #.98 xHO2 + #.98 xRCHO + yR6OOH + #-.06 XC

3-Pentanone MEK-06 0.1 e3 DEK + HV = RCO3 + RO2C + xHO2 + xCCHO + yR6OOH

Methyl Isopropyl 

Ketone

MEK-06 0.1 e3 MIPRK + HV = MECO3 + #.96 RO2C + #.04 RO2XC + #.04 

zRNO3 + #.96 xHO2 + #.96 xACET + yR6OOH + #-.12 XC

Glutaraldehyde C2CHO e1 GLTRALD + HV = HO2 + #.961 RO2C + #.039 RO2XC + 

#.039 zRNO3 + CO + #.961 xRCO3 + yR6OOH + #.882 XC

2,4-pentanedione MEK-06 0.1 e3 24C5-K + HV = MECO3 + RO2C + xMECO3 + xHCHO + 

yR6OOH

Hexanal C2CHO e1 1C6RCHO + HV = HO2 + #1.809 RO2C + #.126 RO2XC + 

#.126 zRNO3 + CO + #.874 xHO2 + #.874 xRCHO + 

yR6OOH + #1.623 XC

4-Methyl-2-Pentanone MEK-06 0.02 e3 MIBK + HV = MECO3 + #1.294 RO2C + #.053 RO2XC + 

#.053 zRNO3 + #.947 xHO2 + #.348 xHCHO + #.613 xRCHO 

+ #.334 xACET + yR6OOH + #.492 XC

Methyl n-Butyl Ketone MEK-06 0.02 e3 MNBK + HV = MECO3 + #1.686 RO2C + #.069 RO2XC + 

#.069 zRNO3 + #.931 xHO2 + #.931 xRCHO + yR6OOH + 

#.792 XC

Methyl t-Butyl Ketone MEK-06 0.02 e3 MTBK + HV = MECO3 + #.961 RO2C + #.039 RO2XC + 

#.039 zRNO3 + #.961 xTBUO + yR6OOH + #-.079 XC

Heptanal C2CHO e1 1C7RCHO + HV = HO2 + #1.717 RO2C + #.186 RO2XC + 

#.186 zRNO3 + CO + #.814 xHO2 + #.814 xRCHO + 

yR6OOH + #2.443 XC

2-methyl-hexanal C2CHO e1 2MEXAL + HV = HO2 + #1.608 RO2C + #.237 RO2XC + 

#.237 zRNO3 + CO + #.763 xHO2 + #.763 xPROD2 + 

yR6OOH
Table B-6 (continued)

242

Compound Phot Data [a] Mechanism

2-Heptanone MEK-06 0.004 e3 C7-KET-2 + HV = MECO3 + #1.809 RO2C + #.126 RO2XC + 

#.126 zRNO3 + #.874 xHO2 + #.874 xRCHO + yR6OOH + 

#1.623 XC

2-Methyl-3-Hexanone MEK-06 0.004 e3 2M-3-HXO + HV = RCO3 + #.98 RO2C + #.02 RO2XC + #.02 

zRNO3 + #.98 xHO2 + #.98 xRCHO + yR6OOH + #.94 XC

Di-Isopropyl Ketone MEK-06 0.004 e3 DIPK + HV = RCO3 + #.96 RO2C + #.04 RO2XC + #.04 

zRNO3 + #.96 xHO2 + #.96 xACET + yR6OOH + #.88 XC

5-Methyl-2-Hexanone MEK-06 0.004 e3 5M2HXO + HV = MECO3 + #1.722 RO2C + #.119 RO2XC + 

#.119 zRNO3 + #.881 xHO2 + #.881 xRCHO + yR6OOH + 

#1.642 XC

3-Methyl-2-Hexanone MEK-06 0.004 e3 3M2HXO + HV = MECO3 + #1.612 RO2C + #.165 RO2XC + 

#.165 zRNO3 + #.835 xHO2 + #.029 xCCHO + #.029 xRCHO 

+ #.107 xMEK + #.699 xPROD2 + yR6OOH + #-.758 XC

Octanal C2CHO e1 1C8RCHO + HV = HO2 + #1.613 RO2C + #.252 RO2XC + 

#.252 zRNO3 + CO + #.748 xHO2 + #.748 xRCHO + 

yR6OOH + #3.244 XC

2-Octanone MEK-06 0.0001 e3 C8-KET-2 + HV = MECO3 + #1.717 RO2C + #.186 RO2XC + 

#.186 zRNO3 + #.814 xHO2 + #.814 xRCHO + yR6OOH + 

#2.443 XC

Hydroxycitronellal C2CHO e1 HYCITRLL + HV = HO2 + #1.43 RO2C + #.372 RO2XC + 

#.372 zRNO3 + CO + #.628 xHO2 + #.006 xHCHO + #.622 

xRCHO + #.006 xPROD2 + yR6OOH + #4.86 XC

Methyl Nitrite CONO 1 ME-NITRT + HV = HCHO + HO2 + NO

Carbon Disulfide CS2 0.012 3 CS2 + HV = SO2 + O3P + XC

methyl iodide CH3I 5 CH3I + OH = RO2C + xHO2 + xHCHO + I

Chloropicrin CLPICER

I

0.87 2 CCL3NO2 + HV = NO2 + RO2C + xCL + XC

Methyl Isothiocyanate MITC 4 MITC + HV = XC + SO2 + #2 O3P

Methyl Isothiocyanate MITC 4 MITC + HV = XC + SO2 + #2 O3P

PROD2 Species #1 MEK-06 0.02 e3 PROD2-1 + HV = MECO3 + #1.013 RO2C + xHO2 + #.033 

xHCHO + #.002 xCCHO + #.987 xRCHO + yR6OOH

PROD2 Species #2 MEK-06 0.004 e3 PROD2-2 + HV = MECO3 + #1.697 RO2C + #.051 RO2XC + 

#.051 zRNO3 + #.949 xHO2 + #1.484 xHCHO + #.736 

xCCHO + #.213 xRCHO + yR6OOH + #.1 XC

PROD2 Species #3 MEK-06 0.0001 e3 PROD2-3 + HV = RCO3 + #1.715 RO2C + #.07 RO2XC + 

#.07 zRNO3 + #.93 xHO2 + #.93 xRCHO + yR6OOH + #.789 

XC

PROD2 Species #4 MEK-06 0.0001 e3 PROD2-4 + HV = RCO3 + #1.809 RO2C + #.126 RO2XC + 

#.126 zRNO3 + #.874 xHO2 + #.077 xCCHO + #.874 xRCHO 

+ yR6OOH + #1.469 XC

PROD2 Species #5 MEK-06 0.0001 e3 PROD2-5 + HV = RCO3 + #1.717 RO2C + #.186 RO2XC + 

#.186 zRNO3 + #.814 xHO2 + #.898 xRCHO + yR6OOH + 

#2.193 XC

RNO3 Species #1 IC3ONO2 e4 RNO3-1 + HV = NO2 + #.606 HO2 + #.394 RO2C + #.394 

CCHO + #.606 MEK + #.394 xHO2 + #.394 xCCHO + #.394 

yROOH

RNO3 Species #2 IC3ONO2 e4 RNO3-2 + HV = NO2 + HO2 + PROD2 + #-1 XC

RNO3 Species #3 IC3ONO2 e4 RNO3-3 + HV = NO2 + #.016 HO2 + #1.226 RO2C + #.081 

RO2XC + #.081 zRNO3 + #.89 CCHO + #.016 PROD2 + 

#.904 xHO2 + #.645 xCCHO + #.495 xMEK + #.085 xPROD2 

+ #.984 yR6OOH + #-.143 XC
Table B-6 (continued)

243

Compound Phot Data [a] Mechanism

RNO3 Species #4 IC3ONO2 e4 RNO3-4 + HV = NO2 + #.441 HO2 + #.483 RO2C + #.075 

RO2XC + #.075 zRNO3 + #.441 HCHO + #.441 RCHO + 

#.483 xHO2 + #.483 xPROD2 + #.559 yR6OOH + #1.882 XC

RNO3 Species #5 IC3ONO2 e4 RNO3-5 + HV = NO2 + #1.422 RO2C + #.215 RO2XC + 

#.215 zRNO3 + #.137 MEK + #.124 PROD2 + #.785 xHO2 + 

#.367 xHCHO + #.341 xCCHO + #.379 xRCHO + #.046 

xACET + #.236 xPROD2 + yR6OOH + #1.678 XC

RNO3 Species #6 IC3ONO2 e4 RNO3-6 + HV = NO2 + #.802 RO2C + #.24 RO2XC + #.24 

zRNO3 + #.76 xHO2 + #.76 xPROD2 + yR6OOH + #4 XC

[a] The first column gives the photolysis set name that refers to the set of absorption cross-sections and (in some 

cases) quantum yields. The second column gives the overall quantum yield, if quantum yields are not given in 

the photolysis set. If blank, then unit quantum yields are used. The third column gives the footnote for the 

measured or estimated absorption cross-sections and quantum yields. Footnotes for measured data are as 

follows. In all these cases, the absorption cross sections are given in Table B-8.

1 Absorption cross-sections from Calvert and Pitts (1966). Unit quantum yields assumed.

2 Absorption cross-sections and quantum yields from Carter et al (1997b). 

3 Absorption cross-sections from current IUPAC (2006) recommendation. Quantum yield is IUPAC (2006) 

upper limit recommendation, but chamber data are best fit is this upper limit is used. See Carter and 

Malkina (2007).

4 Based on data from Alvarez (1993) and Alvarez and Moore (1994).

5 IUPAC (2006) recommendation. Unit quantum yields assumed.

6 IUPAC (2006) recommendation for absorption cross-sections and overall quantum yield.

Footnotes for estimated absorption cross-sections and quantum yields are as follows. In all these cases, the 

photolysis sets are associated with the base mechanism, and the corresponding absorption cross sections and 

quantum yields are given in Table A-3 in Appendix A. See footnotes to Table A-2 for the documentation for the 

values used.

e1 Assumed to have the same photolysis rate as propionaldehyde (model species RCHO).

e2 Assumed to have the same photolysis rate as methacrolein (model species MACR)

e3 Assumed to have the same absorption cross sections of methyl ethyl ketone, but with overall quantum 

yields depending on the carbon number, based on quantum yields that give the best simulations of the 

chamber data for methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, and 2-heptanol. 

Based on these data, overall quantum yields for simple ketones with carbon numbers of 4, 5, 6, 8, and 8 

are assumed to be 0.174, 0.1, 0.02, 0.004, and ~0, respectively. For oxygenated ketones such as 

hydroxyacetone or the PROD2 species, the effective carbon number is the sum of the carbons + OH groups. 

For the purpose of computing an average quantum yield and a photolysis mechanism for PROD2, quantum 

yields of 0.0001 were used for PROD2 species with 8 or more carbons + OH groups. This was necessary in 

order for the mechanisms for these species to be generated.

e4 Assumed to have the same photolysis rate as isopropyl nitrate, as used in the base mechanism for RNO3.
244

Table B-7. Listing of compounds for which mechanisms have been derived. 4. Rate constants and 

mechanisms for reactions with chlorine atoms, where used.

Compound Rate const. [a] Mechanism [b]

Ethane 5.95E-11 1 ETHANE + CL = xHO2 + RO2C + HCL + xCCHO + yROOH

Propane 1.37E-10 2 PROPANE + CL = #.97 xHO2 + #.97 RO2C + #.03 RO2XC + #.03 

zRNO3 + HCL + #.482 xRCHO + #.488 xACET + yROOH + #-.09 XC

n-Butane 2.05E-10 1 N-C4 + CL = HCL + #1.418 RO2C + #.077 RO2XC + #.077 zRNO3 + 

#.923 xHO2 + #.481 xCCHO + #.313 xRCHO + #.37 xMEK + yROOH + 

#.16 XC

n-Pentane 2.80E-10 2 N-C5 + CL = HCL + #1.577 RO2C + #.143 RO2XC + #.143 zRNO3 + 

#.857 xHO2 + #.105 xCCHO + #.328 xRCHO + #.177 xMEK + #.352 

xPROD2 + yR6OOH + #.127 XC

n-Hexane 3.40E-10 2 N-C6 + CL = HCL + #1.591 RO2C + #.22 RO2XC + #.22 zRNO3 + #.78 

xHO2 + #.009 xCCHO + #.215 xRCHO + #.585 xPROD2 + yR6OOH + 

#.51 XC

n-Heptane 3.90E-10 2 N-C7 + CL = HCL + #1.519 RO2C + #.29 RO2XC + #.29 zRNO3 + #.71 

xHO2 + #.143 xRCHO + #.575 xPROD2 + yR6OOH + #1.386 XC

n-Octane 4.60E-10 2 N-C8 + CL = HCL + #1.449 RO2C + #.352 RO2XC + #.352 zRNO3 + 

#.648 xHO2 + #.088 xRCHO + #.561 xPROD2 + yR6OOH + #2.263 XC

n-Nonane 4.80E-10 2 N-C9 + CL = HCL + #1.393 RO2C + #.398 RO2XC + #.398 zRNO3 + 

#.602 xHO2 + #.068 xRCHO + #.535 xPROD2 + yR6OOH + #3.203 XC

n-Decane 5.50E-10 2 N-C10 + CL = HCL + #1.355 RO2C + #.428 RO2XC + #.428 zRNO3 + 

#.572 xHO2 + #.057 xRCHO + #.515 xPROD2 + yR6OOH + #4.17 XC

n-Undecane 6.27E-10 e1 N-C11 + CL = HCL + #1.331 RO2C + #.448 RO2XC + #.448 zRNO3 + 

#.552 xHO2 + #.049 xRCHO + #.503 xPROD2 + yR6OOH + #5.147 XC

n-Dodecane 6.89E-10 e1 N-C12 + CL = HCL + #1.315 RO2C + #.46 RO2XC + #.46 zRNO3 + 

#.54 xHO2 + #.044 xRCHO + #.497 xPROD2 + yR6OOH + #6.131 XC

n-Tridecane 7.51E-10 e1 N-C13 + CL = HCL + #1.305 RO2C + #.467 RO2XC + #.467 zRNO3 + 

#.533 xHO2 + #.039 xRCHO + #.494 xPROD2 + yR6OOH + #7.118 XC

Isobutane 1.43E-10 2 2-ME-C3 + CL = HCL + #1.19 RO2C + #.049 RO2XC + #.049 zRNO3 + 

#.651 xHO2 + #.3 xTBUO + #.239 xHCHO + #.422 xRCHO + #.23 

xACET + yROOH + #.314 XC

Iso-Pentane 2.20E-10 2 2-ME-C4 + CL = HCL + #1.734 RO2C + #.123 RO2XC + #.123 zRNO3 

+ #.869 xHO2 + #.008 xMEO2 + #.044 xHCHO + #.482 xCCHO + #.381 

xRCHO + #.439 xACET + #.042 xMEK + yR6OOH + #.623 XC

2,2-Dimethyl Butane 1.96E-10 e1 22-DM-C4 + CL = HCL + #2.068 RO2C + #.167 RO2XC + #.167 zRNO3 

+ #.549 xHO2 + #.016 xMEO2 + #.268 xTBUO + #.409 xHCHO + #.638 

xCCHO + #.185 xRCHO + #.363 xACET + #.016 xMEK + yR6OOH + 

#.513 XC

2,3-Dimethyl Butane 2.30E-10 2 23-DM-C4 + CL = HCL + #1.733 RO2C + #.164 RO2XC + #.164 zRNO3 

+ #.836 xHO2 + #.047 xHCHO + #.039 xCCHO + #.456 xRCHO + #.734 

xACET + #.001 xMEK + yR6OOH + #1.315 XC

2-Methyl Pentane 2.90E-10 2 2-ME-C5 + CL = HCL + #1.661 RO2C + #.193 RO2XC + #.193 zRNO3 

+ #.807 xHO2 + #.001 xHCHO + #.004 xCCHO + #.625 xRCHO + #.234 

xACET + #.006 xMEK + #.183 xPROD2 + yR6OOH + #1.139 XC

3-Methylpentane 2.80E-10 2 3-ME-C5 + CL = HCL + #1.832 RO2C + #.191 RO2XC + #.191 zRNO3 

+ #.809 xHO2 + #.019 xHCHO + #.784 xCCHO + #.282 xRCHO + #.344 

xMEK + #.047 xPROD2 + yR6OOH + #.762 XC

2,3-Dimethyl Pentane 2.79E-10 e1 23-DM-C5 + CL = HCL + #1.846 RO2C + #.253 RO2XC + #.253 zRNO3 

+ #.747 xHO2 + #.038 xHCHO + #.415 xCCHO + #.313 xRCHO + #.41 

xACET + #.203 xMEK + #.047 xPROD2 + yR6OOH + #1.351 XC
Table B-7 (continued)

245

Compound Rate const. [a] Mechanism [b]

2,4-Dimethyl Pentane 2.90E-10 2 24-DM-C5 + CL = HCL + #1.857 RO2C + #.234 RO2XC + #.234 zRNO3 

+ #.766 xHO2 + #.213 xHCHO + #.009 xCCHO + #.661 xRCHO + #.23 

xACET + #.008 xMEK + #.082 xPROD2 + yR6OOH + #2.163 XC

2-Methyl Hexane 3.50E-10 2 2-ME-C6 + CL = HCL + #1.585 RO2C + #.267 RO2XC + #.267 zRNO3 

+ #.733 xHO2 + #.008 xHCHO + #.019 xCCHO + #.362 xRCHO + #.121 

xACET + #.378 xPROD2 + yR6OOH + #1.633 XC

3-Methyl Hexane 3.30E-10 e1 3-ME-C6 + CL = HCL + #1.67 RO2C + #.269 RO2XC + #.269 zRNO3 + 

#.731 xHO2 + #.005 xHCHO + #.171 xCCHO + #.433 xRCHO + #.133 

xMEK + #.289 xPROD2 + yR6OOH + #1.479 XC

2,4-Dimethyl Hexane 3.41E-10 e1 24-DM-C6 + CL = HCL + #1.752 RO2C + #.34 RO2XC + #.34 zRNO3 + 

#.66 xHO2 + #.103 xHCHO + #.212 xCCHO + #.427 xRCHO + #.055 

xACET + #.065 xMEK + #.227 xPROD2 + yR6OOH + #2.365 XC

2-Methyl Heptane 3.91E-10 e1 2-ME-C7 + CL = HCL + #1.489 RO2C + #.338 RO2XC + #.338 zRNO3 

+ #.662 xHO2 + #.006 xHCHO + #.01 xCCHO + #.229 xRCHO + #.021 

xACET + #.45 xPROD2 + yR6OOH + #2.494 XC

4-Methyl Heptane 3.92E-10 e1 4-ME-C7 + CL = HCL + #1.542 RO2C + #.338 RO2XC + #.338 zRNO3 

+ #.662 xHO2 + #.002 xHCHO + #.004 xCCHO + #.326 xRCHO + #.041 

xMEK + #.411 xPROD2 + yR6OOH + #2.353 XC

2,4-Dimethyl Heptane 4.03E-10 e1 24-DM-C7 + CL = HCL + #1.588 RO2C + #.396 RO2XC + #.396 zRNO3 

+ #.604 xHO2 + #.071 xHCHO + #.007 xCCHO + #.387 xRCHO + #.019 

xACET + #.014 xMEK + #.339 xPROD2 + yR6OOH + #3.226 XC

2-Methyl Octane 4.53E-10 e1 2-ME-C8 + CL = HCL + #1.447 RO2C + #.4 RO2XC + #.4 zRNO3 + #.6 

xHO2 + #.001 xHCHO + #.136 xRCHO + #.013 xACET + #.469 

xPROD2 + yR6OOH + #3.336 XC

4-Methyl Octane 4.54E-10 e1 4-ME-C8 + CL = HCL + #1.472 RO2C + #.395 RO2XC + #.395 zRNO3 

+ #.605 xHO2 + #.001 xHCHO + #.012 xCCHO + #.188 xRCHO + #.004 

xMEK + #.482 xPROD2 + yR6OOH + #3.132 XC

2,6-Dimethyl Octane 4.64E-10 e1 26DM-C8 + CL = HCL + #1.507 RO2C + #.429 RO2XC + #.429 zRNO3 

+ #.571 xHO2 + #.001 xHCHO + #.071 xCCHO + #.262 xRCHO + #.054 

xACET + #.036 xMEK + #.318 xPROD2 + yR6OOH + #4.283 XC

2-Methyl Nonane 5.14E-10 e1 2-ME-C9 + CL = HCL + #1.399 RO2C + #.435 RO2XC + #.435 zRNO3 

+ #.565 xHO2 + #.106 xRCHO + #.012 xACET + #.46 xPROD2 + 

yR6OOH + #4.279 XC

4-Methyl Nonane 5.15E-10 e1 4-ME-C9 + CL = HCL + #1.418 RO2C + #.429 RO2XC + #.429 zRNO3 

+ #.571 xHO2 + #.001 xHCHO + #.007 xCCHO + #.161 xRCHO + #.002 

xMEK + #.466 xPROD2 + yR6OOH + #4.121 XC

2,6-Dimethyl Nonane 5.26E-10 e1 26DM-C9 + CL = HCL + #1.455 RO2C + #.458 RO2XC + #.458 zRNO3 

+ #.542 xHO2 + #.001 xHCHO + #.001 xCCHO + #.219 xRCHO + #.049 

xACET + #.003 xMEK + #.371 xPROD2 + yR6OOH + #5.21 XC

3-Methyl Decane 5.77E-10 e1 3-ME-C10 + CL = HCL + #1.391 RO2C + #.458 RO2XC + #.458 zRNO3 

+ #.542 xHO2 + #.001 xHCHO + #.032 xCCHO + #.096 xRCHO + #.01 

xMEK + #.449 xPROD2 + yR6OOH + #5.166 XC

4-Methyl Decane 5.77E-10 e1 4-ME-C10 + CL = HCL + #1.396 RO2C + #.458 RO2XC + #.458 zRNO3 

+ #.542 xHO2 + #.001 xHCHO + #.001 xCCHO + #.118 xRCHO + #.002 

xMEK + #.462 xPROD2 + yR6OOH + #5.118 XC

3,6-Dimethyl Decane 5.89E-10 e1 36DM-C10 + CL = HCL + #1.46 RO2C + #.482 RO2XC + #.482 zRNO3 

+ #.518 xHO2 + #.001 xHCHO + #.056 xCCHO + #.165 xRCHO + #.029 

xMEK + #.406 xPROD2 + yR6OOH + #5.955 XC

3-Methyl Undecane 6.39E-10 e1 3-ME-C11 + CL = HCL + #1.367 RO2C + #.469 RO2XC + #.469 zRNO3 

+ #.531 xHO2 + #.001 xHCHO + #.029 xCCHO + #.084 xRCHO + #.009 

xMEK + #.449 xPROD2 + yR6OOH + #6.146 XC
Table B-7 (continued)

246

Compound Rate const. [a] Mechanism [b]

5-Methyl Undecane 6.39E-10 e1 5-ME-C11 + CL = HCL + #1.366 RO2C + #.469 RO2XC + #.469 zRNO3 

+ #.531 xHO2 + #.003 xCCHO + #.098 xRCHO + #.464 xPROD2 + 

yR6OOH + #6.098 XC

2,4,6,8-Tetramethyl 

Nonane

5.49E-10 e1 2468TMC9 + CL = #.488 xHO2 + #1.531 RO2C + #.512 RO2XC + #.512 

zRNO3 + HCL + #.011 xHCHO + #.001 xCCHO + #.35 xRCHO + #.038 

xACET + #.001 xMEK + #.28 xPROD2 + yR6OOH + #7.067 XC

3,6-Dimethyl Undecane 6.51E-10 e1 36DM-C11 + CL = HCL + #1.428 RO2C + #.488 RO2XC + #.488 

zRNO3 + #.512 xHO2 + #.001 xHCHO + #.046 xCCHO + #.152 xRCHO 

+ #.023 xMEK + #.406 xPROD2 + yR6OOH + #6.993 XC

3-Methyl Dodecane 7.01E-10 e1 3-ME-C12 + CL = HCL + #1.351 RO2C + #.476 RO2XC + #.476 zRNO3 

+ #.524 xHO2 + #.001 xHCHO + #.026 xCCHO + #.076 xRCHO + #.008 

xMEK + #.45 xPROD2 + yR6OOH + #7.13 XC

5-Methyl Dodecane 7.01E-10 e1 5-ME-C12 + CL = HCL + #1.352 RO2C + #.478 RO2XC + #.478 zRNO3 

+ #.522 xHO2 + #.003 xCCHO + #.087 xRCHO + #.461 xPROD2 + 

yR6OOH + #7.099 XC

Cyclopentane 3.09E-10 e1 CYCC5 + CL = HCL + #2.438 RO2C + #.224 RO2XC + #.224 zRNO3 + 

#.776 xHO2 + #.054 xCO + #.756 xRCHO + #.02 xMEK + yR6OOH + 

#1.255 XC

Cyclohexane 3.50E-10 2 CYCC6 + CL = HCL + #1.272 RO2C + #.201 RO2XC + #.201 zRNO3 + 

#.799 xHO2 + #.203 xRCHO + #.597 xPROD2 + yR6OOH + #.608 XC

Methylcyclopentane 3.21E-10 e1 ME-CYCC5 + CL = HCL + #2.241 RO2C + #.31 RO2XC + #.31 zRNO3 

+ #.596 xHO2 + #.092 xMECO3 + #.003 xRCO3 + #.028 xCO + #.052 

xHCHO + #.679 xRCHO + #.001 xMEK + #.007 xPROD2 + yR6OOH + 

#1.785 XC

1,2-

dimethylcyclopentane

3.32E-10 e1 2468TMC9 + CL = #.488 xHO2 + #1.531 RO2C + #.512 RO2XC + #.512 

zRNO3 + HCL + #.011 xHCHO + #.001 xCCHO + #.35 xRCHO + #.038 

xACET + #.001 xMEK + #.28 xPROD2 + yR6OOH + #7.067 XC

Ethyl Cyclopentane 3.83E-10 e1 2468TMC9 + CL = #.488 xHO2 + #1.531 RO2C + #.512 RO2XC + #.512 

zRNO3 + HCL + #.011 xHCHO + #.001 xCCHO + #.35 xRCHO + #.038 

xACET + #.001 xMEK + #.28 xPROD2 + yR6OOH + #7.067 XC

Methylcyclohexane 3.90E-10 2 ME-CYCC6 + CL = HCL + #1.6 RO2C + #.318 RO2XC + #.318 zRNO3 

+ #.682 xHO2 + #.044 xHCHO + #.003 xCCHO + #.377 xRCHO + #.31 

xPROD2 + yR6OOH + #2.057 XC

Ethylcyclohexane 4.45E-10 e1 ET-CYCC6 + CL = HCL + #1.528 RO2C + #.365 RO2XC + #.365 

zRNO3 + #.634 xHO2 + #.002 xHCHO + #.135 xCCHO + #.298 xRCHO 

+ #.34 xPROD2 + yR6OOH + #2.602 XC

Propene 2.67E-10 3 PROPENE + CL = #.124 HCL + #.971 RO2C + #.029 RO2XC + #.029

zRNO3 + #.971 xHO2 + #.124 xMACR + yROOH + #2.328 XC

1-Butene 3.39E-10 4 2468TMC9 + CL = #.488 xHO2 + #1.531 RO2C + #.512 RO2XC + #.512 

zRNO3 + HCL + #.011 xHCHO + #.001 xCCHO + #.35 xRCHO + #.038 

xACET + #.001 xMEK + #.28 xPROD2 + yR6OOH + #7.067 XC 

(Mechanism is average of those for propene and 1-butene)

1-Pentene 4.05E-10 4 1-PENTEN + CL = #.408 HCL + #1.666 RO2C + #.136 RO2XC + #.136 

zRNO3 + #.864 xHO2 + #.039 xHCHO + #.225 xCCHO + #.079 xRCHO 

+ #.223 xMACR + #.021 xMVK + #.042 xIPRD + yR6OOH + #2.271 XC

3-Methyl-1-Butene 3.52E-10 5 Use mechanism derived for the 2-butenes

1-Hexene Use mechanism and rate constant of 1-pentene

1-Heptene Use mechanism and rate constant of 1-pentene

1-Octene Use mechanism and rate constant of 1-pentene

1-Nonene Use mechanism and rate constant of 1-pentene

1-Decene Use mechanism and rate constant of 1-pentene

1-Undecene Use mechanism and rate constant of 1-pentene
Table B-7 (continued)

247

Compound Rate const. [a] Mechanism [b]

Isobutene 3.25E-10 5 2468TMC9 + CL = #.488 xHO2 + #1.531 RO2C + #.512 RO2XC + #.512 

zRNO3 + HCL + #.011 xHCHO + #.001 xCCHO + #.35 xRCHO + #.038 

xACET + #.001 xMEK + #.28 xPROD2 + yR6OOH + #7.067 XC

2-Methyl-1-Butene 3.82E-10 5 2468TMC9 + CL = #.488 xHO2 + #1.531 RO2C + #.512 RO2XC + #.512 

zRNO3 + HCL + #.011 xHCHO + #.001 xCCHO + #.35 xRCHO + #.038 

xACET + #.001 xMEK + #.28 xPROD2 + yR6OOH + #7.067 XC

cis-2-Butene 3.88E-10 5 C-2-BUTE + CL = #.199 HCL + #.971 RO2C + #.079 RO2XC + #.079 

zRNO3 + #.919 xHO2 + #.002 xMEO2 + #.047 xHCHO + #.104 xMVK + 

#.08 xIPRD + yROOH + #2.66 XC

trans-2-Butene 3.55E-10 3 T-2-BUTE + CL = #.199 HCL + #.923 RO2C + #.077 RO2XC + #.077 

zRNO3 + #.921 xHO2 + #.002 xMEO2 + #.104 xMVK + #.082 xIPRD + 

yROOH + #2.709 XC

2-Methyl-2-Butene 3.23E-10 5 Use mechanism derived for the 2-butenes

cis-2-Pentene 3.94E-10 e1 C-2-PENT + CL = #.33 HCL + #1.729 RO2C + #.14 RO2XC + #.14 

zRNO3 + #.282 xHO2 + #.001 xMEO2 + #.577 xCL + #.116 xHCHO + 

#.742 xCCHO + #.577 xRCHO + #.052 xMVK + #.231 xIPRD + 

yR6OOH + #-.535 XC

trans-2-Pentene 3.94E-10 e1 T-2-PENT + CL = #.33 HCL + #1.634 RO2C + #.134 RO2XC + #.134 

zRNO3 + #.287 xHO2 + #.002 xMEO2 + #.577 xCL + #.078 xHCHO + 

#.687 xCCHO + #.577 xRCHO + #.052 xMVK + #.237 xIPRD + 

yR6OOH + #-.381 XC

Cis-2-Hexene Use mechanism and rate constant derived for the 2-pentenes

Trans-2-Hexene Use mechanism and rate constant derived for the 2-pentenes

Trans-2-Heptene Use mechanism and rate constant derived for the 2-pentenes

Trans-3-Heptene Use mechanism and rate constant derived for the 2-pentenes

Trans-4-Octene Use mechanism and rate constant derived for the 2-pentenes

Trans-4-Nonene Use mechanism and rate constant derived for the 2-pentenes

3,4-Diethyl-2-Hexene Use mechanism and rate constant derived for the 2-pentenes

Trans-4-Decene Use mechanism and rate constant derived for the 2-pentenes

Trans-5-Undecene Use mechanism and rate constant derived for the 2-pentenes

Cyclohexene Use mechanism and rate constant derived for the 2-pentenes

1,3-Butadiene 4.90E-10 2 13-BUTDE + CL = #.39 xHO2 + #.541 xCL + #1.884 RO2C + #.069 

RO2XC + #.069 zRNO3 + #.863 xHCHO + #.457 xMACR + #.473 

xIPRD + yROOH + #-1.47 XC

alpha Pinene 5.46E-10 e1 A-PINENE + CL = #.548 HCL + #2.258 RO2C + #.582 RO2XC + #.582 

zRNO3 + #.252 xHO2 + #.034 xMECO3 + #.05 xRCO3 + #.016 

xMACO3 + #.068 xCL + #.035 xCO + #.158 xHCHO + #.185 xRCHO + 

#.274 xACET + #.007 xGLY + #.003 xBACL + #.006 xAFG1 + #.006 

xAFG2 + #.003 xMVK + #.158 xIPRD + yROOH + #-6.231 XC

Toluene 6.20E-11 6 TOLUENE + CL = #.894 RO2C + #.106 RO2XC + #.106 zRNO3 + #.894 

xHO2 + #.894 xBALD + yR6OOH + #.106 XC

Ethyl Benzene 1.70E-10 e1 C2-BENZ + CL = #.864 RO2C + #.136 RO2XC + #.136 zRNO3 + #.864 

xHO2 + #.864 xPROD2 + yR6OOH + #2 XC

n-Propyl Benzene 2.28E-10 e1 N-C3-BEN + CL = #.838 RO2C + #.162 RO2XC + #.162 zRNO3 + #.838 

xHO2 + #.838 xPROD2 + yR6OOH + #3 XC

Isopropyl Benzene 

(cumene)

1.56E-10 e1 I-C3-BEN + CL = #.838 RO2C + #.162 RO2XC + #.162 zRNO3 + #.838 

xHO2 + #.838 xPROD2 + yR6OOH + #3 XC

C10 Monosubstituted 

Benzenes

2.48E-10 e1 C10-BEN1 + CL = #.82 RO2C + #.18 RO2XC + #.18 zRNO3 + #.82 

xHO2 + #.82 xPROD2 + yR6OOH + #4 XC

t-Butyl Benzene 9.82E-11 e1 T-C4-BEN + CL = #.82 RO2C + #.18 RO2XC + #.18 zRNO3 + #.82 

xHO2 + #.82 xPROD2 + yR6OOH + #4 XC
Table B-7 (continued)

248

Compound Rate const. [a] Mechanism [b]

C11 Monosubstituted 

Benzenes

3.10E-10 e1 C11-BEN1 + CL = #.808 RO2C + #.192 RO2XC + #.192 zRNO3 + #.808 

xHO2 + #.808 xPROD2 + yR6OOH + #5 XC

C12 Monosubstituted 

Benzenes

3.72E-10 e1 C12-BEN1 + CL = #.8 RO2C + #.2 RO2XC + #.2 zRNO3 + #.8 xHO2 + 

#.8 xPROD2 + yR6OOH + #6 XC

C13 Monosubstituted 

Benzenes

4.33E-10 e1 C13-BEN1 + CL = #.795 RO2C + #.205 RO2XC + #.205 zRNO3 + #.795 

xHO2 + #.795 xPROD2 + yR6OOH + #7 XC

C14 Monosubstituted 

Benzenes

4.95E-10 e1 C14-BEN1 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + #.792 

xHO2 + #.792 xPROD2 + yR6OOH + #8 XC

C15 Monosubstituted 

Benzenes

5.57E-10 e1 C15-BEN1 + CL = #.791 RO2C + #.209 RO2XC + #.209 zRNO3 + #.791 

xHO2 + #.791 xPROD2 + yR6OOH + #9 XC

C16 Monosubstituted 

Benzenes

6.19E-10 e1 C16-BEN1 + CL = #.789 RO2C + #.211 RO2XC + #.211 zRNO3 + #.789 

xHO2 + #.789 xPROD2 + yR6OOH + #10 XC

m-Xylene 1.35E-10 6 M-XYLENE + CL = #.864 RO2C + #.136 RO2XC + #.136 zRNO3 + 

#.864 xHO2 + #.864 xBALD + yR6OOH + #1.136 XC

o-Xylene 1.40E-10 6 O-XYLENE + CL = #.864 RO2C + #.136 RO2XC + #.136 zRNO3 + 

#.864 xHO2 + #.864 xBALD + yR6OOH + #1.136 XC

p-Xylene 1.44E-10 6 P-XYLENE + CL = #.864 RO2C + #.136 RO2XC + #.136 zRNO3 + 

#.864 xHO2 + #.864 xBALD + yR6OOH + #1.136 XC

m-Ethyl Toluene 2.39E-10 e1 M-ET-TOL + CL = #.838 RO2C + #.162 RO2XC + #.162 zRNO3 + #.838 

xHO2 + #.243 xBALD + #.595 xPROD2 + yR6OOH + #2.757 XC

o-Ethyl Toluene 2.39E-10 e1 O-ET-TOL + CL = #.838 RO2C + #.162 RO2XC + #.162 zRNO3 + #.838 

xHO2 + #.243 xBALD + #.595 xPROD2 + yR6OOH + #2.757 XC

p-Ethyl Toluene 2.39E-10 e1 P-ET-TOL + CL = #.838 RO2C + #.162 RO2XC + #.162 zRNO3 + #.838 

xHO2 + #.243 xBALD + #.595 xPROD2 + yR6OOH + #2.757 XC

m-c10 disubstituted 

benzenes

3.02E-10 e1 MC10BEN2 + CL = #.82 RO2C + #.18 RO2XC + #.18 zRNO3 + #.82 

xHO2 + #.094 xBALD + #.725 xPROD2 + yR6OOH + #3.906 XC

o-c10 disubstituted 

benzenes

3.02E-10 e1 OC10BEN2 + CL = #.82 RO2C + #.18 RO2XC + #.18 zRNO3 + #.82 

xHO2 + #.094 xBALD + #.725 xPROD2 + yR6OOH + #3.906 XC

p-c10 disubstituted 

benzenes

3.02E-10 e1 PC10BEN2 + CL = #.82 RO2C + #.18 RO2XC + #.18 zRNO3 + #.82 

xHO2 + #.094 xBALD + #.725 xPROD2 + yR6OOH + #3.906 XC

1-methyl-4-

isopropylbenzene (pcymene)

2.25E-10 e1 P-CYMENE + CL = #.82 RO2C + #.18 RO2XC + #.18 zRNO3 + #.82 

xHO2 + #.253 xBALD + #.567 xPROD2 + yR6OOH + #3.747 XC

m-c11 disubstituted 

benzenes

3.53E-10 e1 MC11BEN2 + CL = #.808 RO2C + #.192 RO2XC + #.192 zRNO3 + 

#.808 xHO2 + #.054 xBALD + #.754 xPROD2 + yR6OOH + #4.946 XC

o-c11 disubstituted 

benzenes

3.53E-10 e1 OC11BEN2 + CL = #.808 RO2C + #.192 RO2XC + #.192 zRNO3 + 

#.808 xHO2 + #.054 xBALD + #.754 xPROD2 + yR6OOH + #4.946 XC

p-c11 disubstituted 

benzenes

3.53E-10 e1 PC11BEN2 + CL = #.808 RO2C + #.192 RO2XC + #.192 zRNO3 + #.808 

xHO2 + #.054 xBALD + #.754 xPROD2 + yR6OOH + #4.946 XC

m-c12 disubstituted 

benzenes

4.00E-10 e1 MC12BEN2 + CL = #.8 RO2C + #.2 RO2XC + #.2 zRNO3 + #.8 xHO2 + 

#.035 xBALD + #.765 xPROD2 + yR6OOH + #5.965 XC

o-c12 disubstituted 

benzenes

4.00E-10 e1 OC12BEN2 + CL = #.8 RO2C + #.2 RO2XC + #.2 zRNO3 + #.8 xHO2 + 

#.035 xBALD + #.765 xPROD2 + yR6OOH + #5.965 XC

p-c12 disubstituted 

benzenes

4.00E-10 e1 PC12BEN2 + CL = #.8 RO2C + #.2 RO2XC + #.2 zRNO3 + #.8 xHO2 + 

#.035 xBALD + #.765 xPROD2 + yR6OOH + #5.965 XC

m-c13 disubstituted 

benzenes

4.58E-10 e1 MC13BEN2 + CL = #.795 RO2C + #.205 RO2XC + #.205 zRNO3 + 

#.795 xHO2 + #.795 xPROD2 + yR6OOH + #7 XC

o-c13 disubstituted 

benzenes

4.58E-10 e1 OC13BEN2 + CL = #.795 RO2C + #.205 RO2XC + #.205 zRNO3 + 

#.795 xHO2 + #.795 xPROD2 + yR6OOH + #7 XC

p-c13 disubstituted 

benzenes

4.58E-10 e1 PC13BEN2 + CL = #.795 RO2C + #.205 RO2XC + #.205 zRNO3 + #.795 

xHO2 + #.795 xPROD2 + yR6OOH + #7 XC
Table B-7 (continued)

249

Compound Rate const. [a] Mechanism [b]

m-c14 disubstituted 

benzenes

5.20E-10 e1 MC14BEN2 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + 

#.792 xHO2 + #.792 xPROD2 + yR6OOH + #8 XC

o-c14 disubstituted 

benzenes

5.20E-10 e1 OC14BEN2 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + 

#.792 xHO2 + #.792 xPROD2 + yR6OOH + #8 XC

p-c14 disubstituted 

benzenes

5.20E-10 e1 PC14BEN2 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + #.792 

xHO2 + #.792 xPROD2 + yR6OOH + #8 XC

m-c15 disubstituted 

benzenes

5.81E-10 e1 MC15BEN2 + CL = #.791 RO2C + #.209 RO2XC + #.209 zRNO3 + 

#.791 xHO2 + #.791 xPROD2 + yR6OOH + #9 XC

o-c15 disubstituted 

benzenes

5.81E-10 e1 OC15BEN2 + CL = #.791 RO2C + #.209 RO2XC + #.209 zRNO3 + 

#.791 xHO2 + #.791 xPROD2 + yR6OOH + #9 XC

p-c15 disubstituted 

benzenes

5.81E-10 e1 PC15BEN2 + CL = #.791 RO2C + #.209 RO2XC + #.209 zRNO3 + #.791 

xHO2 + #.791 xPROD2 + yR6OOH + #9 XC

m-c16 disubstituted 

benzenes

6.43E-10 e1 MC16BEN2 + CL = #.789 RO2C + #.211 RO2XC + #.211 zRNO3 + 

#.789 xHO2 + #.789 xPROD2 + yR6OOH + #10 XC

o-c16 disubstituted 

benzenes

6.43E-10 e1 OC16BEN2 + CL = #.789 RO2C + #.211 RO2XC + #.211 zRNO3 + 

#.789 xHO2 + #.789 xPROD2 + yR6OOH + #10 XC

p-c16 disubstituted 

benzenes

6.43E-10 e1 PC16BEN2 + CL = #.789 RO2C + #.211 RO2XC + #.211 zRNO3 + #.789 

xHO2 + #.789 xPROD2 + yR6OOH + #10 XC

1,2,3-Trimethyl 

Benzene

2.42E-10 e2 123-TMB + CL = #.838 RO2C + #.162 RO2XC + #.162 zRNO3 + #.838 

xHO2 + #.838 xBALD + yR6OOH + #2.162 XC

1,2,4-Trimethyl 

Benzene

2.42E-10 e2 124-TMB + CL = #.838 RO2C + #.162 RO2XC + #.162 zRNO3 + #.838 

xHO2 + #.838 xBALD + yR6OOH + #2.162 XC

1,3,5-Trimethyl 

Benzene

2.42E-10 7 135-TMB + CL = #.838 RO2C + #.162 RO2XC + #.162 zRNO3 + #.838 

xHO2 + #.838 xBALD + yR6OOH + #2.162 XC

1,2,3-c10 trisubstituted 

benzenes

3.09E-10 e1 3C10BEN3 + CL = #.808 RO2C + #.192 RO2XC + #.192 zRNO3 + #.808 

xHO2 + #.363 xBALD + #.445 xPROD2 + yR6OOH + #3.637 XC

1,2,4-c10 trisubstituted 

benzenes

3.09E-10 e1 4C10BEN3 + CL = #.808 RO2C + #.192 RO2XC + #.192 zRNO3 + #.808 

xHO2 + #.363 xBALD + #.445 xPROD2 + yR6OOH + #3.637 XC

1,3,5-c10 trisubstituted 

benzenes

3.09E-10 e1 5C10BEN3 + CL = #.808 RO2C + #.192 RO2XC + #.192 zRNO3 + #.808 

xHO2 + #.363 xBALD + #.445 xPROD2 + yR6OOH + #3.637 XC

1,2,3-c11 trisubstituted 

benzenes

3.88E-10 e1 3C11BEN3 + CL = #.8 RO2C + #.2 RO2XC + #.2 zRNO3 + #.8 xHO2 + 

#.215 xBALD + #.585 xPROD2 + yR6OOH + #4.785 XC

1,2,4-c11 trisubstituted 

benzenes

3.88E-10 e1 4C11BEN3 + CL = #.8 RO2C + #.2 RO2XC + #.2 zRNO3 + #.8 xHO2 + 

#.215 xBALD + #.585 xPROD2 + yR6OOH + #4.785 XC

1,3,5-c11 trisubstituted 

benzenes

3.88E-10 e1 5C11BEN3 + CL = #.8 RO2C + #.2 RO2XC + #.2 zRNO3 + #.8 xHO2 + 

#.215 xBALD + #.585 xPROD2 + yR6OOH + #4.785 XC

1,2,3-c12 trisubstituted 

benzenes

4.13E-10 e1 3C12BEN3 + CL = #.795 RO2C + #.205 RO2XC + #.205 zRNO3 + #.795 

xHO2 + #.179 xBALD + #.616 xPROD2 + yR6OOH + #5.821 XC

1,2,4-c12 trisubstituted 

benzenes

4.13E-10 e1 4C12BEN3 + CL = #.795 RO2C + #.205 RO2XC + #.205 zRNO3 + #.795 

xHO2 + #.179 xBALD + #.616 xPROD2 + yR6OOH + #5.821 XC

1,3,5-c12 trisubstituted 

benzenes

4.13E-10 e1 5C12BEN3 + CL = #.795 RO2C + #.205 RO2XC + #.205 zRNO3 + #.795 

xHO2 + #.179 xBALD + #.616 xPROD2 + yR6OOH + #5.821 XC

1,2,3-c13 trisubstituted 

benzenes

4.87E-10 e1 3C13BEN3 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + #.792 

xHO2 + #.113 xBALD + #.679 xPROD2 + yR6OOH + #6.887 XC

1,2,4-c13 trisubstituted 

benzenes

4.87E-10 e1 4C13BEN3 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + #.792 

xHO2 + #.113 xBALD + #.679 xPROD2 + yR6OOH + #6.887 XC

1,3,5-c13 trisubstituted 

benzenes

4.87E-10 e1 5C13BEN3 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + #.792 

xHO2 + #.113 xBALD + #.679 xPROD2 + yR6OOH + #6.887 XC

1,2,3-c14 trisubstituted 

benzenes

5.50E-10 e1 3C14BEN3 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + #.792 

xHO2 + #.075 xBALD + #.717 xPROD2 + yR6OOH + #7.925 XC
Table B-7 (continued)

250

Compound Rate const. [a] Mechanism [b]

1,2,4-c14 trisubstituted 

benzenes

5.50E-10 e1 4C14BEN3 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + #.792 

xHO2 + #.075 xBALD + #.717 xPROD2 + yR6OOH + #7.925 XC

1,3,5-c14 trisubstituted 

benzenes

5.50E-10 e1 5C14BEN3 + CL = #.792 RO2C + #.208 RO2XC + #.208 zRNO3 + #.792 

xHO2 + #.075 xBALD + #.717 xPROD2 + yR6OOH + #7.925 XC

1,2,3-c15 trisubstituted 

benzenes

5.88E-10 e1 3C15BEN3 + CL = #.791 RO2C + #.209 RO2XC + #.209 zRNO3 + #.791 

xHO2 + #.047 xBALD + #.744 xPROD2 + yR6OOH + #8.953 XC

1,2,4-c15 trisubstituted 

benzenes

5.88E-10 e1 4C15BEN3 + CL = #.791 RO2C + #.209 RO2XC + #.209 zRNO3 + #.791 

xHO2 + #.047 xBALD + #.744 xPROD2 + yR6OOH + #8.953 XC

1,3,5-c15 trisubstituted 

benzenes

5.88E-10 e1 5C15BEN3 + CL = #.791 RO2C + #.209 RO2XC + #.209 zRNO3 + #.791 

xHO2 + #.047 xBALD + #.744 xPROD2 + yR6OOH + #8.953 XC

1,2,3-c16 trisubstituted 

benzenes

6.49E-10 e1 3C16BEN3 + CL = #.789 RO2C + #.211 RO2XC + #.211 zRNO3 + #.789 

xHO2 + #.021 xBALD + #.768 xPROD2 + yR6OOH + #9.979 XC

1,2,4-c16 trisubstituted 

benzenes

6.49E-10 e1 4C16BEN3 + CL = #.789 RO2C + #.211 RO2XC + #.211 zRNO3 + #.789 

xHO2 + #.021 xBALD + #.768 xPROD2 + yR6OOH + #9.979 XC

1,3,5-c16 trisubstituted 

benzenes

6.49E-10 e1 5C16BEN3 + CL = #.789 RO2C + #.211 RO2XC + #.211 zRNO3 + #.789 

xHO2 + #.021 xBALD + #.768 xPROD2 + yR6OOH + #9.979 XC

PROD2 Species #1 1.35E-10 e1 PROD2-1 + CL = HCL + #.512 HO2 + #.456 RO2C + #.032 RO2XC + 

#.032 zRNO3 + #.512 RCHO + #.429 xHO2 + #.018 xMECO3 + #.009 

xRCO3 + #.438 xHCHO + #.447 xRCHO + #.488 yR6OOH + #1.431 XC

PROD2 Species #2 1.46E-10 e1 PROD2-2 + CL = HCL + #.476 HO2 + #.651 RO2C + #.063 RO2XC + 

#.063 zRNO3 + #.476 RCHO + #.445 xHO2 + #.016 xMECO3 + #.621 

xHCHO + #.208 xRCHO + #.253 xMEK + #.524 yR6OOH + #1.904 XC

PROD2 Species #3 1.78E-10 e1 PROD2-3 + CL = HCL + #.255 HO2 + #.687 RO2C + #.107 RO2XC + 

#.107 zRNO3 + #.255 PROD2 + #.568 xHO2 + #.069 xRCO3 + #.124 

xHCHO + #.313 xCCHO + #.624 xRCHO + #.745 yR6OOH + #1.994 XC

PROD2 Species #4 2.41E-10 e1 PROD2-4 + CL = HCL + #.18 HO2 + #.782 RO2C + #.164 RO2XC + 

#.164 zRNO3 + #.18 PROD2 + #.629 xHO2 + #.027 xRCO3 + #.231 

xCCHO + #.882 xRCHO + #.002 xPROD2 + #.82 yR6OOH + #2.73 XC

PROD2 Species #5 3.02E-10 e1 PROD2-5 + CL = HCL + #.146 HO2 + #.821 RO2C + #.214 RO2XC + 

#.214 zRNO3 + #.146 PROD2 + #.634 xHO2 + #.007 xRCO3 + #.796 

xRCHO + #.2 xPROD2 + #.854 yR6OOH + #3.237 XC

RNO3 Species #1 5.05E-11 e1 RNO3-1 + CL = HCL + #.105 NO2 + #1.408 RO2C + #.065 RO2XC + 

#.065 zRNO3 + #.105 MEK + #.115 xNO2 + #.715 xHO2 + #.23 xCCHO 

+ #.715 xRNO3 + #.895 yROOH + #.065 XN + #-1.559 XC

RNO3 Species #2 1.56E-10 e1 RNO3-2 + CL = HCL + #.052 NO2 + #.291 HO2 + #.837 RO2C + #.058 

RO2XC + #.058 zRNO3 + #.052 RCHO + #.291 RNO3 + #.599 xHO2 + 

#.003 xHCHO + #.373 xCCHO + #.599 xRNO3 + #.657 yR6OOH + 

#.058 XN + #-1.594 XC

RNO3 Species #3 1.45E-10 e1 RNO3-3 + CL = HCL + #.037 NO2 + #1.511 RO2C + #.185 RO2XC + 

#.185 zRNO3 + #.037 PROD2 + #.405 xNO2 + #.373 xHO2 + #.077 

xHCHO + #.991 xCCHO + #.05 xRCHO + #.031 xMEK + #.06 xPROD2 

+ #.373 xRNO3 + #.963 yR6OOH + #.185 XN + #-.261 XC

RNO3 Species #4 2.43E-10 e1 RNO3-4 + CL = HCL + #.021 NO2 + #.036 HO2 + #1.158 RO2C + #.178 

RO2XC + #.178 zRNO3 + #.021 PROD2 + #.036 RNO3 + #.159 xNO2 + 

#.605 xHO2 + #.008 xCCHO + #.011 xRCHO + #.159 xPROD2 + #.605 

xRNO3 + #.943 yR6OOH + #.178 XN + #.952 XC

RNO3 Species #5 1.61E-10 e1 RNO3-5 + CL = HCL + #1.449 RO2C + #.304 RO2XC + #.304 zRNO3 + 

#.27 xNO2 + #.426 xHO2 + #.188 xHCHO + #.197 xCCHO + #.058 

xRCHO + #.016 xACET + #.216 xMEK + #.054 xPROD2 + #.426 

xRNO3 + yR6OOH + #.304 XN + #1.625 XC
Table B-7 (continued)

251

Compound Rate const. [a] Mechanism [b]

RNO3 Species #6 3.99E-10 e1 RNO3-6 + CL = HCL + #.013 NO2 + #1.33 RO2C + #.42 RO2XC + #.42 

zRNO3 + #.013 PROD2 + #.003 xNO2 + #.564 xHO2 + #.003 xPROD2 + 

#.564 xRNO3 + #.987 yR6OOH + #.42 XN + #4 XC

[a] Rate constant for the reaction with Cl atoms in cm3 molec-1s

-1

. The temperature dependences are unknown, so 

they are assumed to be temperature independent. Footnotes for measured rate constants are as follows:

1 IUPAC (2006) Recommendation

2 Atkinson (1997) Recommendation

3 Average of values tabulated by Wang et al (2002). Value of Wang et al (2002) placed on an absolute basis 

using the Atkinson (1997)-recommended rate constant for n-heptane.

4 Average of value of Coquet et al (2000), placed on an absolute basis using the Atkinson (1997)-

recommended n-hexane rate constant, and the value of Wang et al (2002), placed on an absolute basis using 

the Atkinson (1997)-recommended rate constant for n-heptane.

5 Value of Wang et al (2002), placed on an absolute basis using the Atkinson (1997)-recommended rate 

constant for n-heptane.

6 Average of values tabulated by Wang et al (2005).

7 Wang et al (2005)

Footnotes for estimated rate constants are as follows:

e1 Estimated using the group-additivity estimation assignments as indicated on Table 3.

e2 Estimated to have the same rate constant as 1,3,5-trimethylbenzene.

[b] Mechanisms derived for the mechanism generation system except for the aromatics, whose mechanisms were 

derived as discussed in the "Updated Aromatics Mechanisms" section.
252

Table B-8. Absorption cross sections used for the photolysis reactions for represented photoreactive 

VOCs that are not in the base mechanism.

a) Phot set HOCCHO: Glycolaldehyde photolysis

Note: Quantum yield of 0.75 is used for all wavelengths (not shown below)

wl abs wl abs wl abs wl abs wl abs wl abs

205 3.91E-19 228 6.37E-21 251 2.50E-20 274 5.40E-20 297 3.29E-20 320 3.29E-21

206 3.37E-19 229 6.37E-21 252 2.65E-20 275 5.41E-20 298 3.17E-20 321 2.85E-21

207 2.87E-19 230 6.49E-21 253 2.82E-20 276 5.39E-20 299 3.02E-20 322 2.49E-21

208 2.46E-19 231 6.44E-21 254 2.97E-20 277 5.42E-20 300 2.90E-20 323 2.13E-21

209 2.12E-19 232 6.80E-21 255 3.09E-20 278 5.37E-20 301 2.74E-20 324 1.85E-21

210 1.81E-19 233 7.23E-21 256 3.21E-20 279 5.34E-20 302 2.51E-20 325 1.47E-21

211 1.53E-19 234 7.85E-21 257 3.39E-20 280 5.34E-20 303 2.26E-20 326 1.28E-21

212 1.30E-19 235 8.33E-21 258 3.59E-20 281 5.37E-20 304 2.07E-20 327 1.05E-21

213 1.12E-19 236 8.80E-21 259 3.75E-20 282 5.37E-20 305 1.91E-20 328 8.70E-22

214 9.40E-20 237 9.39E-21 260 3.89E-20 283 5.25E-20 306 1.77E-20 329 8.40E-22

215 7.84E-20 238 1.03E-20 261 4.02E-20 284 5.12E-20 307 1.64E-20 330 6.80E-22

216 6.49E-20 239 1.11E-20 262 4.13E-20 285 5.01E-20 308 1.50E-20 331 5.80E-22

217 5.30E-20 240 1.20E-20 263 4.24E-20 286 4.93E-20 309 1.36E-20 332 4.30E-22

218 4.26E-20 241 1.28E-20 264 4.40E-20 287 4.80E-20 310 1.25E-20 333 4.00E-22

219 3.37E-20 242 1.38E-20 265 4.60E-20 288 4.67E-20 311 1.15E-20 334 4.00E-22

220 2.65E-20 243 1.50E-20 266 4.75E-20 289 4.58E-20 312 1.03E-20 335 3.90E-22

221 2.13E-20 244 1.59E-20 267 4.85E-20 290 4.50E-20 313 8.84E-21 336 0.00E+00

222 1.65E-20 245 1.71E-20 268 4.92E-20 291 4.41E-20 314 7.71E-21

223 1.36E-20 246 1.83E-20 269 4.99E-20 292 4.19E-20 315 6.89E-21

224 1.12E-20 247 1.95E-20 270 5.05E-20 293 3.96E-20 316 5.97E-21

225 9.33E-21 248 2.09E-20 271 5.14E-20 294 3.76E-20 317 5.16E-21

226 7.83E-21 249 2.22E-20 272 5.23E-20 295 3.59E-20 318 4.55E-21

227 6.91E-21 250 2.36E-20 273 5.36E-20 296 3.46E-20 319 3.96E-21

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation (including 

0.75 overall quantum yield)

b) Phot set CONO: Absorption cross-sections for methyl nitrite

wl abs wl abs wl abs wl abs wl abs wl abs

250 1.55e-18 295 8.60e-20 320 1.45e-19 345 1.45e-19 370 1.24e-19 395 2.70e-20

260 1.00e-18 300 7.00e-20 325 9.70e-20 350 2.91e-19 375 9.70e-20 400 1.10e-20

280 1.83e-19 305 6.50e-20 330 2.37e-19 355 1.78e-19 380 4.90e-20 405 1.40e-20

285 1.49e-19 310 9.10e-20 335 1.19e-19 360 1.62e-19 385 4.30e-20 410 -

290 1.08e-19 315 8.10e-20 340 3.07e-19 365 1.67e-19 390 4.30e-20

Wavelengths in nm and absorption cross-sections in cm-2. Absorption cross-sections from Calvert and 

Pitts (1966). Unit quantum yields assumed.
Table B-8 (continued)

253

c) Phot set CS2: Absorption cross-sections for carbon disulfide

wl abs wl abs wl abs wl abs wl abs wl abs

280 5.30e-22 296 1.13e-20 312 6.69e-20 328 2.85e-20 344 5.56e-21 360 1.19e-21

281 6.20e-22 297 1.86e-20 313 8.15e-20 329 2.85e-20 345 3.53e-21 361 4.20e-22

282 8.00e-22 298 2.29e-20 314 7.84e-20 330 3.80e-20 346 3.50e-21 362 4.80e-22

283 1.03e-21 299 2.02e-20 315 9.44e-20 331 1.30e-20 347 3.28e-21 363 2.10e-22

284 1.22e-21 300 1.88e-20 316 7.04e-20 332 3.06e-20 348 1.09e-21 364 3.70e-22

285 1.58e-21 301 3.27e-20 317 9.46e-20 333 1.55e-20 349 3.68e-21 365 1.20e-22

286 2.09e-21 302 3.17e-20 318 7.16e-20 334 1.51e-20 350 2.39e-21 366 3.60e-22

287 2.54e-21 303 3.13e-20 319 9.80e-20 335 1.38e-20 351 1.27e-21 367 2.30e-22

288 3.09e-21 304 4.44e-20 320 4.52e-20 336 8.61e-21 352 2.55e-21 368 2.00e-22

289 4.45e-21 305 4.46e-20 321 6.12e-20 337 1.38e-20 353 6.60e-22 369 1.10e-22

290 4.38e-21 306 3.66e-20 322 4.22e-20 338 5.91e-21 354 1.72e-21 370 1.80e-22

291 6.35e-21 307 5.12e-20 323 5.18e-20 339 1.12e-20 355 2.47e-21 371

292 6.40e-21 308 7.10e-20 324 3.52e-20 340 4.89e-21 356 5.20e-22

293 8.78e-21 309 4.93e-20 325 8.63e-20 341 3.86e-21 357 1.33e-21

294 8.01e-21 310 8.84e-20 326 5.02e-20 342 5.73e-21 358 5.50e-22

295 1.14e-20 311 5.61e-20 327 3.48e-20 343 3.87e-21 359 5.90e-22

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation for absorption 

cross-sections. Unit quantum yields assumed.

d) Phot set CH3I: Absorption cross-sections for methyl iodide

wl Abs wl Abs wl abs wl abs wl abs

280 2.80e-19 300 2.03e-20 320 2.15e-21 340 2.30e-22 360 1.30e-23

285 1.52e-19 305 1.09e-20 325 1.24e-21 345 1.27e-22 365 4.00e-24

290 7.79e-20 310 6.19e-21 330 7.00e-22 350 6.70e-23 370 -

295 3.92e-20 315 3.56e-21 335 3.30e-22 355 2.60e-23

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation.

e) Phot set BRNO2: Absorption cross-sections for BrNO2 used in the methyl iodide mechanism for INO2

wl Abs wl Abs wl abs wl abs wl abs wl abs

280 8.80e-19 310 1.10e-19 340 1.60e-19 370 1.70e-19 400 1.40e-19 430 9.00e-20

285 6.30e-19 315 1.10e-19 345 1.50e-19 375 1.80e-19 405 1.40e-19 435 8.00e-20

290 4.40e-19 320 1.00e-19 350 1.60e-19 380 1.70e-19 410 1.30e-19 440 7.00e-20

295 3.00e-19 325 1.20e-19 355 1.60e-19 385 1.70e-19 415 1.20e-19 445 7.00e-20

300 2.00e-19 330 1.30e-19 360 1.80e-19 390 1.60e-19 420 1.10e-19 450 6.00e-20

305 1.50e-19 335 1.40e-19 365 1.90e-19 395 1.50e-19 425 1.00e-19 480 -

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation.

f) Phot set HI: Absorption cross-sections for HI used in the methyl iodide mechanism.

wl Abs wl Abs wl abs wl abs wl abs

280 8.94e-20 295 3.17e-20 310 1.01e-20 325 2.47e-21 340 4.70e-22

285 6.37e-20 300 2.23e-20 315 6.53e-21 330 1.45e-21 347 -

290 4.51e-20 305 1.52e-20 320 4.09e-21 335 8.30e-22

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation.
Table B-8 (continued)

254

g) Phot set HOI: Absorption cross-sections for HOI used in the methyl iodide mechanism.

wl Abs wl Abs wl abs wl abs wl abs wl abs

280 7.70e-21 320 2.07e-18 360 2.58e-18 400 3.22e-18 440 1.13e-18 480 2.96e-20

285 2.26e-20 325 2.72e-18 365 2.21e-18 405 3.32e-18 445 8.13e-19 485 1.61e-20

290 5.89e-20 330 3.29e-18 370 1.98e-18 410 3.27e-18 450 5.63e-19 490 8.60e-21

295 1.37e-19 335 3.70e-18 375 1.94e-18 415 3.07e-18 455 3.76e-19 496 -

300 2.86e-19 340 3.85e-18 380 2.07e-18 420 2.75e-18 460 2.42e-19

305 5.41e-19 345 3.77e-18 385 2.33e-18 425 2.35e-18 465 1.50e-19

310 9.26e-19 350 3.47e-18 390 2.66e-18 430 1.92e-18 470 9.04e-20

315 1.45e-18 355 3.04e-18 395 2.98e-18 435 1.50e-18 475 5.25e-20

Wavelengths in nm and absorption cross-sections in cm-2. IUPAC (2006) recommendation.

h) Phot set CLPICERI: Absorption cross-sections for chloropicrin

wl abs wl abs wl abs wl abs wl abs wl abs

280 1.67e-19 300 6.44e-20 320 1.38e-20 340 5.20e-21 360 1.54e-21 380 5.57e-22

282 1.62e-19 302 5.47e-20 322 1.23e-20 342 4.80e-21 362 2.13e-21 382 4.66e-22

284 1.54e-19 304 4.68e-20 324 1.10e-20 344 4.36e-21 364 1.78e-21 384 4.68e-22

286 1.44e-19 306 3.97e-20 326 9.94e-21 346 4.00e-21 366 1.25e-21 386 1.70e-22

288 1.34e-19 308 3.33e-20 328 8.98e-21 348 3.68e-21 368 1.28e-21 388 5.02e-22

290 1.23e-19 310 2.79e-20 330 8.18e-21 350 3.34e-21 370 1.04e-21 390 3.50e-22

292 1.10e-19 312 2.36e-20 332 7.54e-21 352 3.05e-21 372 1.08e-21 392 -

294 9.82e-20 314 2.03e-20 334 6.82e-21 354 2.70e-21 374 7.13e-22

296 8.71e-20 316 1.77e-20 336 6.27e-21 356 2.51e-21 376 6.96e-22

298 7.57e-20 318 1.55e-20 338 5.69e-21 358 2.30e-21 378 5.85e-22

Wavelengths in nm and absorption cross-sections in cm-2. Absorption cross-sections from Carter et al 

(1997b). Unit quantum yields assumed.

i) Phot set MITC: Absorption cross-sections for methyl isothiocyanate.

wl abs wl abs wl abs wl abs

285.6 3.44e-20 302.5 1.23e-20 317.5 3.48e-21 332.5 4.00e-22

290.0 2.66e-20 307.5 8.52e-21 322.5 1.96e-21 337.5 1.70e-22

297.5 1.70e-20 312.5 5.63e-21 327.5 9.60e-22 340.0 -

Wavelengths in nm and absorption cross-sections in cm-2. Absorption cross-sections from Alvarez and 

Moore (1994). Unit quantum yields assumed.
Table B-8 (continued)

255

j) Phot set PAA: Peroxy acetic acid absorption cross-sections

wl abs wl abs wl abs wl abs wl abs wl abs

210 3.81E-19 234 7.03E-20 258 1.93E-20 282 4.44E-21 306 7.80E-22 330 9.00E-23

212 3.31E-19 236 6.31E-20 260 1.71E-20 284 3.86E-21 308 6.90E-22 332 1.10E-22

214 2.95E-19 238 5.61E-20 262 1.53E-20 286 3.34E-21 310 6.20E-22 334 1.10E-22

216 2.54E-19 240 5.03E-20 264 1.35E-20 288 2.97E-21 312 4.50E-22 336 9.00E-23

218 2.17E-19 242 4.83E-20 266 1.21E-20 290 2.56E-21 314 4.40E-22 338 9.00E-23

220 1.89E-19 244 4.31E-20 268 1.06E-20 292 2.26E-21 316 4.00E-22 340 6.00E-23

222 1.60E-19 246 3.82E-20 270 9.45E-21 294 1.93E-21 318 3.50E-22 342 3.00E-23

224 1.39E-19 248 3.41E-20 272 8.35E-21 296 1.70E-21 320 2.50E-22 344 0.00E+00

226 1.20E-19 250 3.05E-20 274 7.42E-21 298 1.41E-21 322 2.00E-22

228 1.05E-19 252 2.71E-20 276 6.51E-21 300 1.23E-21 324 2.00E-22

230 9.10E-20 254 2.42E-20 278 5.74E-21 302 1.07E-21 326 1.70E-22

232 8.01E-20 256 2.16E-20 280 5.06E-21 304 9.40E-22 328 1.40E-22

Wavelengths in nm and absorption cross-sections in cm-2. Orlando and Tyldall (2003)
256

Table B-9. Lumped molecule representations used in the SAPRC-07 mechanism.

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

Branched C5 Alkanes 1 Iso-Pentane

Branched C6 Alkanes 0.5 2,3-Dimethyl Butane 0.25 3-Methylpentane 0.25 2-Methyl Pentane

C6 Cycloalkanes 1 Cyclohexane

Branched C7 Alkanes 0.5 2,4-Dimethyl Pentane 0.25 3-Methyl Hexane 0.25 2-Methyl Hexane

C7 Cycloalkanes 1 Methylcyclohexane

Branched C8 Alkanes 0.5 2,4-Dimethyl Hexane 0.25 4-Methyl Heptane 0.25 2-Methyl Heptane

C8 Bicycloalkanes 1 Methylcyclohexane

C8 Cycloalkanes 1 Ethylcyclohexane

Branched C9 Alkanes 0.5 2,4-Dimethyl Heptane 0.25 4-Methyl Octane 0.25 2-Methyl Octane

C9 Bicycloalkanes 0.5 Propyl Cyclohexane 0.5 1-Ethyl-4-Methyl 

Cyclohexane

C9 Cycloalkanes 0.5 Propyl Cyclohexane 0.5 1-Ethyl-4-Methyl 

Cyclohexane

Branched C10 Alkanes 0.5 2,6-Dimethyl Octane 0.25 4-Methyl Nonane 0.25 2-Methyl Nonane

C10 Bicycloalkanes 0.34 Butyl Cyclohexane 0.33 1-Methyl-3-Isopropyl 

Cyclohexane

0.33 1,4-Diethyl-Cyclohexane

isobutylclohexane; (2-

methylpropyl) cyclohexane

1 Butyl Cyclohexane

sec-butylcyclohexane 1 Butyl Cyclohexane

C10 Cycloalkanes 0.34 Butyl Cyclohexane 0.33 1-Methyl-3-Isopropyl 

Cyclohexane

0.33 1,4-Diethyl-Cyclohexane

Branched C11 alkanes 0.5 2,6-Dimethyl Nonane 0.25 4-Methyl Decane 0.25 3-Methyl Decane

C11 Bicycloalkanes 0.34 Pentyl Cyclohexane 0.33 1,3-Diethyl-5-Methyl 

Cyclohexane

0.33 1-Ethyl-2-Propyl 

Cyclohexane

C11 Cycloalkanes 0.34 Pentyl Cyclohexane 0.33 1,3-Diethyl-5-Methyl 

Cyclohexane

0.33 1-Ethyl-2-Propyl 

Cyclohexane

Branched C12 Alkanes 0.5 3,6-Dimethyl Decane 0.25 5-Methyl Undecane 0.25 3-Methyl Undecane

C12 Tricycloalkanes 0.34 Hexyl Cyclohexane 0.33 1,3,5-Triethyl Cyclohexane 0.33 1-Methyl-4-Pentyl 

Cyclohexane

C12 Bicycloalkanes 0.34 Hexyl Cyclohexane 0.33 1,3,5-Triethyl Cyclohexane 0.33 1-Methyl-4-Pentyl 

Cyclohexane

C12 Cycloalkanes 0.34 Hexyl Cyclohexane 0.33 1,3,5-Triethyl Cyclohexane 0.33 1-Methyl-4-Pentyl 

Cyclohexane
Table B-9 (continued)

257

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

Branched C13 Alkanes 0.5 3,6-Dimethyl Undecane 0.25 5-Methyl Dodecane 0.25 3-Methyl Dodecane

C13 Tricycloalkanes 0.34 Heptyl Cyclohexane 0.33 1,3-Diethyl-5-Propyl 

Cyclohexane

0.33 1-Methyl-2-HexylCyclohexane

C13 Bicycloalkanes 0.34 Heptyl Cyclohexane 0.33 1,3-Diethyl-5-Propyl 

Cyclohexane

0.33 1-Methyl-2-HexylCyclohexane

C13 Cycloalkanes 0.34 Heptyl Cyclohexane 0.33 1,3-Diethyl-5-Propyl 

Cyclohexane

0.33 1-Methyl-2-HexylCyclohexane

Branched C14 Alkanes 0.5 3,7-Dimethyl Dodecane 0.25 6-Methyl Tridecane 0.25 3-Methyl Tridecane

C14 Tricycloalkanes 0.34 Octyl Cyclohexane 0.33 1,3-Dipropyl-5-Ethyl 

Cyclohexane

0.33 trans 1-Methyl-4-Heptyl 

Cyclohexane

C14 Bicycloalkanes 0.34 Octyl Cyclohexane 0.33 1,3-Dipropyl-5-Ethyl 

Cyclohexane

0.33 trans 1-Methyl-4-Heptyl 

Cyclohexane

C14 Cycloalkanes 0.34 Octyl Cyclohexane 0.33 1,3-Dipropyl-5-Ethyl 

Cyclohexane

0.33 trans 1-Methyl-4-Heptyl 

Cyclohexane

Branched C15 Alkanes 0.5 3,7-Dimethyl Tridecane 0.25 6-Methyl Tetradecane 0.25 3-Methyl Tetradecane

C15 Tricycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C15 Bicycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C15 Cycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

Branched C16 Alkanes 0.5 4,8-Dimethyl Tetradecane 0.25 7-Methyl Pentadecane 0.25 3-Methyl Pentadecane

C16 Tricycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C16 Bicycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C16 Cycloalkanes 0.34 Decyl Cyclohexane 0.33 1,3-Propyl-5-Butyl 

Cyclohexane

0.33 1-Methyl-4-Nonyl 

Cyclohexane

n-C17 1 n-C16

Branched C17 Alkanes 0.5 4,8-Dimethyl Tetradecane 0.25 7-Methyl Pentadecane 0.25 3-Methyl Pentadecane

C17 Tricycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C17 Bicycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane
Table B-9 (continued)

258

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

C17 Cycloalkanes 0.34 Decyl Cyclohexane 0.33 1,3-Propyl-5-Butyl 

Cyclohexane

0.33 1-Methyl-4-Nonyl 

Cyclohexane

n-C18 1 n-C16

Branched C18 Alkanes 0.5 4,8-Dimethyl Tetradecane 0.25 7-Methyl Pentadecane 0.25 3-Methyl Pentadecane

C18 Tricycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C18 Bicycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C18 Cycloalkanes 0.34 Decyl Cyclohexane 0.33 1,3-Propyl-5-Butyl 

Cyclohexane

0.33 1-Methyl-4-Nonyl 

Cyclohexane

n-C19 1 n-C16

Branched C19 Alkanes 0.5 4,8-Dimethyl Tetradecane 0.25 7-Methyl Pentadecane 0.25 3-Methyl Pentadecane

C19 Tricycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C19 Bicycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C19 Cycloalkanes 0.34 Decyl Cyclohexane 0.33 1,3-Propyl-5-Butyl 

Cyclohexane

0.33 1-Methyl-4-Nonyl 

Cyclohexane

n-C20 1 n-C16

Branched C20 Alkanes 0.5 4,8-Dimethyl Tetradecane 0.25 7-Methyl Pentadecane 0.25 3-Methyl Pentadecane

C20 Tricycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C20 Bicycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C20 Cycloalkanes 0.34 Decyl Cyclohexane 0.33 1,3-Propyl-5-Butyl 

Cyclohexane

0.33 1-Methyl-4-Nonyl 

Cyclohexane

n-C21 1 n-C16

Branched C21 Alkanes 0.5 4,8-Dimethyl Tetradecane 0.25 7-Methyl Pentadecane 0.25 3-Methyl Pentadecane

C21 Tricycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C21 Bicycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C21 Cycloalkanes 0.34 Decyl Cyclohexane 0.33 1,3-Propyl-5-Butyl 

Cyclohexane

0.33 1-Methyl-4-Nonyl 

Cyclohexane

n-C22 1 n-C16
Table B-9 (continued)

259

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

Branched C22 Alkanes 0.5 4,8-Dimethyl Tetradecane 0.25 7-Methyl Pentadecane 0.25 3-Methyl Pentadecane

C22 Tricycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C22 Bicycloalkanes 0.34 Nonyl Cyclohexane 0.33 1,3,5-Tripropyl Cyclohexane 0.33 1-Methyl-2-Octyl 

Cyclohexane

C22 Cycloalkanes 0.34 Decyl Cyclohexane 0.33 1,3-Propyl-5-Butyl 

Cyclohexane

0.33 1-Methyl-4-Nonyl 

Cyclohexane

C4 Terminal Alkenes 1 1-Butene

C4 Internal Alkenes 0.5 trans-2-Butene 0.5 cis-2-Butene

C4 Alkenes 0.5 1-Butene 0.25 trans-2-Butene 0.25 cis-2-Butene

C5 Terminal Alkenes 1 1-Pentene

2-Pentenes 0.5 cis-2-Pentene 0.5 trans-2-Pentene

C5 Internal Alkenes 0.5 cis-2-Pentene 0.5 trans-2-Pentene

Cis 1,3-Pentadiene 1 Trans 1,3-Pentadiene

Cyclopentadiene 1 Cyclopentene

C5 Alkenes 0.5 1-Pentene 0.25 cis-2-Pentene 0.25 trans-2-Pentene

C6 Terminal Alkenes 1 1-Hexene

Cis 4-Methyl-2-Pentene 1 Trans 4-Methyl-2-Pentene

2-Hexenes 0.5 Cis-2-Hexene 0.5 Trans-2-Hexene

C6 Internal Alkenes 0.5 Cis-2-Hexene 0.5 Trans-2-Hexene

trans,trans-2,4-hexadiene 1 Trans-2-Hexene

Trans 1,3-Hexadiene 1 Trans 1,3-Pentadiene

C6 Cyclic or di-olefins 0.5 Cis-2-Hexene 0.5 Trans-2-Hexene

C6 Alkenes 0.5 1-Heptene 0.25 Cis-2-Hexene 0.25 Trans-2-Hexene

C7 Cyclic or di-olefins 1 Trans-2-Heptene

2-Heptenes 0.5 Trans-3-Heptene 0.5 Cis-3-Heptene

C7 Terminal Alkenes 1 1-Heptene

C7 Internal Alkenes 1 Trans-3-Heptene

C7 Alkenes 0.5 1-Heptene 0.5 Trans-3-Heptene

C8 Cyclic or di-olefins 1 Trans-4-Octene

3-Octenes 1 Trans-3-Octene

C8 Terminal Alkenes 1 1-Octene

C8 Internal Alkenes 1 Trans-4-Octene

C8 Alkenes 0.5 1-Octene 0.5 Trans-4-Octene
Table B-9 (continued)

260

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

C9 Terminal Alkenes 1 1-Nonene

4-Nonene 1 Trans-4-Nonene

3-Nonenes 1 Trans-4-Nonene

C9 Internal Alkenes 1 Trans-4-Nonene

C9 Cyclic or di-olefins 1 Trans-4-Nonene

C9 Alkenes 0.5 1-Nonene 0.5 Trans-4-Nonene

C10 Terminal Alkenes 1 1-Decene

C10 3-Alkenes 1 Trans-4-Decene

C10 Internal Alkenes 1 Trans-4-Decene

C10 Cyclic or di-olefins 1 Trans-4-Decene

Camphene 1 a-pinene

Terpene 0.4 a-Pinene 0.25 b-Pinene 0.1 d-Limonene

0.15 3-Carene 0.1 Sabinene

C10 Alkenes 0.333 1-Decene 0.667 Trans-4-Decene

C11 Terminal Alkenes 1 1-Undecene

C11 3-Alkenes 1 Trans-5-Undecene

C11 Internal Alkenes 1 Trans-5-Undecene

C11 Cyclic or di-olefins 1 Trans-5-Undecene

C11 Alkenes 0.5 1-Undecene 0.5 Trans-5-Undecene

C12 Terminal Alkenes 1 1-Dodecene

C12 2-Alkenes 1 Trans-5-Dodecene

C12 3-Alkenes 1 Trans-5-Dodecene

C12 Internal Alkenes 1 Trans-5-Dodecene

C12 Cyclic or di-olefins 1 Trans-5-Dodecene

C12 Alkenes 0.5 1-Dodecene 0.5 Trans-5-Dodecene

C13 Terminal Alkenes 1 1-Tridecene

C13 3-Alkenes 1 Trans-5-Tridecene

C13 Internal Alkenes 1 Trans-5-Tridecene

C13 Cyclic or di-olefins 1 Trans-5-Tridecene

C13 Alkenes 0.5 1-Tridecene 0.5 Trans-5-Tridecene

C14 Terminal Alkenes 1 1-Tetradecene

C14 3-Alkenes 1 Trans-5-Tetradecene

C14 Internal Alkenes 1 Trans-5-Tetradecene

C14 Cyclic or di-olefins 1 Trans-5-Tetradecene
Table B-9 (continued)

261

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

C14 Alkenes 0.5 1-Tetradecene 0.5 Trans-5-Tetradecene

1-pentadecene 1 1-Tetradecene

C15 Terminal Alkenes 1 1-Tetradecene

C15 3-Alkenes 1 Trans-5-Pentadecene

C15 Internal Alkenes 1 Trans-5-Pentadecene

C15 Cyclic or di-olefins 1 Trans-5-Pentadecene

C15 Alkenes 0.5 1-Tetradecene 0.5 Trans-5-Pentadecene

C8 Disubstituted Benzenes 0.34 m-Xylene 0.33 o-Xylene 0.33 p-Xylene

Isomers of Ethylbenzene 0.25 m-Xylene 0.25 o-Xylene 0.25 p-Xylene

0.25 Ethyl Benzene

C9 Monosubstituted Benzenes 1 n-Propyl Benzene

C9 Disubstituted Benzenes 0.334 m-Ethyl Toluene 0.333 o-Ethyl Toluene 0.333 p-Ethyl Toluene

C9 Trisubstituted Benzenes 0.334 1,2,4-Trimethyl Benzene 0.333 1,2,3-Trimethyl Benzene 0.333 1,3,5-Trimethyl Benzene

Isomers of Propylbenzene 0.111 1,3,5-Trimethyl Benzene 0.111 1,2,3-Trimethyl Benzene 0.111 1,2,4-Trimethyl Benzene

0.334 n-Propyl Benzene 0.111 m-Ethyl Toluene 0.111 o-Ethyl Toluene

0.111 p-Ethyl Toluene

Indene 1 Styrene

Indan 1 Tetralin

Allylbenzene 1 Styrene

a-Methyl Styrene 1 Styrene

C9 Styrenes 1 Styrene

n-Butyl Benzene 1 C10 Monosubstituted Benzenes

s-Butyl Benzene 1 C10 Monosubstituted Benzenes

o-cymene; 1-methyl-2-(1-

methylethyl)benzene

1 o-c10 disubstituted benzenes

1-methyl-2-n-propylbenzene 1 o-c10 disubstituted benzenes

m-cymene; 1-methyl-3-(1-

methylethyl)benzene

1 m-c10 disubstituted benzenes

1-methyl-3-n-propylbenzene 1 m-c10 disubstituted benzenes

1-methyl-4-n-propylbenzene 1 p-c10 disubstituted benzenes

C10 Disubstituted Benzenes 0.334 m-c10 disubstituted benzenes 0.333 o-c10 disubstituted benzenes 0.333 p-c10 disubstituted benzenes

m-Diethyl Benzene 1 m-c10 disubstituted benzenes

o-Diethyl Benzene 1 o-c10 disubstituted benzenes

p-Diethyl Benzene 1 p-c10 disubstituted benzenes
Table B-9 (continued)

262

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

1,2,3,4-tetramethylbenzene 0.334 1,2,4-c10 trisubstituted benzenes 0.333 1,2,3-c10 trisubstituted 

benzenes

0.333 1,3,5-c10 trisubstituted 

benzenes

1,2,4,5-tetramethylbenzene 0.334 1,2,4-c10 trisubstituted benzenes 0.333 1,2,3-c10 trisubstituted 

benzenes

0.333 1,3,5-c10 trisubstituted 

benzenes

1,2-dimethyl-3-ethylbenzene 1 1,2,3-c10 trisubstituted benzenes

1,2-dimethyl-4-ethylbenzene 1 1,2,4-c10 trisubstituted benzenes

1,3-dimethyl-2-ethylbenzene 1 1,2,3-c10 trisubstituted benzenes

1,3-dimethyl-4-ethylbenzene 1 1,2,4-c10 trisubstituted benzenes

1,3-dimethyl-5-ethylbenzene 1 1,3,5-c10 trisubstituted benzenes

1,4-dimethyl-2-ethylbenzene 1 1,2,4-c10 trisubstituted benzenes

1,2,3,5 Tetramethyl Benzene 0.334 1,2,4-c10 trisubstituted benzenes 0.333 1,2,3-c10 trisubstituted 

benzenes

0.333 1,3,5-c10 trisubstituted 

benzenes

C10 Trisubstituted Benzenes 0.334 1,2,4-c10 trisubstituted benzenes 0.333 1,2,3-c10 trisubstituted 

benzenes

0.333 1,3,5-c10 trisubstituted 

benzenes

C10 Tetrasubstituted Benzenes 0.334 1,2,4-c10 trisubstituted benzenes 0.333 1,2,3-c10 trisubstituted 

benzenes

0.333 1,3,5-c10 trisubstituted 

benzenes

Isomers of Butylbenzene 0.334 C10 Monosubstituted Benzenes 0.111 o-c10 disubstituted benzenes 0.111 m-c10 disubstituted benzenes

0.111 p-c10 disubstituted benzenes 0.111 1,2,3-c10 trisubstituted 

benzenes

0.111 1,2,4-c10 trisubstituted 

benzenes

0.111 1,3,5-c10 trisubstituted benzenes

Methyl Indans 1 Tetralin

C10 Styrenes 1 Styrene

n-pentylbenzene 1 C11 Monosubstituted Benzenes

1-butyl-2-methylbenzene 1 o-c11 disubstituted benzenes

1-ethyl-2-n-propylbenzene 1 o-c11 disubstituted benzenes

o-t-butyl toluene; 1-(1,1-

dimethylethyl)-2-methylbenzene

1 o-c11 disubstituted benzenes

1-methyl-3-n-butyl-benzene 1 m-c11 disubstituted benzenes

p-Isobutyl toluene; 1-methyl-4(2-

methylpropyl) benzene

1 p-c11 disubstituted benzenes

C11 Disubstituted Benzenes 0.334 m-c11 disubstituted benzenes 0.333 o-c11 disubstituted benzenes 0.333 p-c11 disubstituted benzenes

Pentamethylbenzene 0.334 1,2,4-c11 trisubstituted benzenes 0.333 1,2,3-c11 trisubstituted 

benzenes

0.333 1,3,5-c11 trisubstituted 

benzenes

1-methyl-3,5-diethylbenzene 1 1,3,5-c11 trisubstituted benzenes
Table B-9 (continued)

263

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

C11 Trisubstituted Benzenes 0.334 1,2,4-c11 trisubstituted benzenes 0.333 1,2,3-c11 trisubstituted 

benzenes

0.333 1,3,5-c11 trisubstituted 

benzenes

C11 Tetrasubstituted Benzenes 0.334 1,2,4-c11 trisubstituted benzenes 0.333 1,2,3-c11 trisubstituted 

benzenes

0.333 1,3,5-c11 trisubstituted 

benzenes

C11 Pentasubstituted Benzenes 0.334 1,2,4-c11 trisubstituted benzenes 0.333 1,2,3-c11 trisubstituted 

benzenes

0.333 1,3,5-c11 trisubstituted 

benzenes

Isomers of Pentylbenzene 0.334 C10 Monosubstituted Benzenes 0.111 o-c11 disubstituted benzenes 0.111 o-c11 disubstituted benzenes

0.111 p-c11 disubstituted benzenes 0.111 1,2,3-c11 trisubstituted 

benzenes

0.111 1,2,4-c11 trisubstituted 

benzenes

0.111 1,3,5-c11 trisubstituted benzenes

C11 Tetralin or Indan 1 Tetralin

1-Methyl Naphthalene 1 Methyl Naphthalenes

2-Methyl Naphthalene 1 Methyl Naphthalenes

1,3-di-n-propylbenzene 1 o-c12 disubstituted benzenes

1,4 diisopropyl benzene 1 p-c12 disubstituted benzenes

3-Isopropyl Cumene; 1,3-

diisopropyl benzene

1 m-c12 disubstituted benzenes

C12 Disubstituted Benzenes 0.334 m-c12 disubstituted benzenes 0.333 o-c12 disubstituted benzenes 0.333 p-c12 disubstituted benzenes

1-(1,1-dimethylethyl)-3,5-

dimethylbenzene

1 1,3,5-c12 trisubstituted benzenes

C12 Trisubstituted Benzenes 0.334 1,2,4-c12 trisubstituted benzenes 0.333 1,2,3-c12 trisubstituted 

benzenes

0.333 1,3,5-c12 trisubstituted 

benzenes

C12 Tetrasubstituted Benzenes 0.334 1,2,4-c12 trisubstituted benzenes 0.333 1,2,3-c12 trisubstituted 

benzenes

0.333 1,3,5-c12 trisubstituted

benzenes

C12 Pentasubstituted Benzenes 0.334 1,2,4-c12 trisubstituted benzenes 0.333 1,2,3-c12 trisubstituted 

benzenes

0.333 1,3,5-c12 trisubstituted 

benzenes

C12 Hexasubstituted Benzenes 0.334 1,2,4-c12 trisubstituted benzenes 0.333 1,2,3-c12 trisubstituted 

benzenes

0.333 1,3,5-c12 trisubstituted 

benzenes

Isomers of Hexylbenzene 0.334 C10 Monosubstituted Benzenes 0.111 o-c12 disubstituted benzenes 0.111 o-c12 disubstituted benzenes

0.111 p-c12 disubstituted benzenes 0.111 1,2,3-c12 trisubstituted 

benzenes

0.111 1,2,4-c12 trisubstituted 

benzenes

0.111 1,3,5-c12 trisubstituted benzenes

C12 Tetralin or Indan 1 Tetralin

1-Ethylnaphthalene 1 Methyl Naphthalenes

C12 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene
Table B-9 (continued)

264

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

C12 Monosubstituted Naphthalene 1 Methyl Naphthalenes

C12 Disubstituted Naphthalenes 1 2,3-Dimethyl Naphthalene

Dimethyl Naphthalenes 1 2,3-Dimethyl Naphthalene

C13 Disubstituted Benzenes 0.334 m-c13 disubstituted benzenes 0.333 o-c13 disubstituted benzenes 0.333 p-c13 disubstituted benzenes

C13 Trisubstituted Benzenes 0.334 1,2,4-c13 trisubstituted benzenes 0.333 1,2,3-c13 trisubstituted 

benzenes

0.333 1,3,5-c13 trisubstituted 

benzenes

C13 Tetralin or Indan 1 Tetralin

C13 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

C13 Monosubstituted Naphthalene 1 Methyl Naphthalenes

C13 Disubstituted Naphthalenes 1 2,3-Dimethyl Naphthalene

C13 Trisubstituted Naphthalenes 1 2,3-Dimethyl Naphthalene

C14 Disubstituted Benzenes 0.334 m-c14 disubstituted benzenes 0.333 o-c14 disubstituted benzenes 0.333 p-c14 disubstituted benzenes

C14 Trisubstituted Benzenes 0.334 1,2,4-c14 trisubstituted benzenes 0.333 1,2,3-c14 trisubstituted 

benzenes

0.333 1,3,5-c14 trisubstituted 

benzenes

C14 Tetralin or Indan 1 Tetralin

C14 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

C15 Disubstituted Benzenes 0.334 m-c15 disubstituted benzenes 0.333 o-c15 disubstituted benzenes 0.333 p-c15 disubstituted benzenes

C15 Trisubstituted Benzenes 0.334 1,2,4-c15 trisubstituted benzenes 0.333 1,2,3-c15 trisubstituted 

benzenes

0.333 1,3,5-c15 trisubstituted 

benzenes

C15 Tetralin or Indan 1 Tetralin

C15 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

C16 Disubstituted Benzenes 0.334 m-c16 disubstituted benzenes 0.333 o-c16 disubstituted benzenes 0.333 p-c16 disubstituted benzenes

C16 Trisubstituted Benzenes 0.334 1,2,4-c16 trisubstituted benzenes 0.333 1,2,3-c16 trisubstituted 

benzenes

0.333 1,3,5-c16 trisubstituted 

benzenes

C16 Tetralin or Indan 1 Tetralin

C16 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

C17 Monosubstituted Benzenes 1 C16 Monosubstituted Benzenes

C17 Disubstituted Benzenes 0.334 m-c16 disubstituted benzenes 0.333 o-c16 disubstituted benzenes 0.333 p-c16 disubstituted benzenes

C17 Trisubstituted Benzenes 0.334 1,2,4-c16 trisubstituted benzenes 0.333 1,2,3-c16 trisubstituted 

benzenes

0.333 1,3,5-c16 trisubstituted 

benzenes

C17 Tetralin or Indan 1 Tetralin

C17 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

C18 Monosubstituted Benzenes 1 C16 Monosubstituted Benzenes

C18 Disubstituted Benzenes 0.334 m-c16 disubstituted benzenes 0.333 o-c16 disubstituted benzenes 0.333 p-c16 disubstituted benzenes
Table B-9 (continued)

265

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

C18 Trisubstituted Benzenes 0.334 1,2,4-c16 trisubstituted benzenes 0.333 1,2,3-c16 trisubstituted 

benzenes

0.333 1,3,5-c16 trisubstituted 

benzenes

C18 Tetralin or Indan 1 Tetralin

C18 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

C19 Monosubstituted Benzenes 1 C16 Monosubstituted Benzenes

C19 Disubstituted Benzenes 0.334 m-c16 disubstituted benzenes 0.333 o-c16 disubstituted benzenes 0.333 p-c16 disubstituted benzenes

C19 Trisubstituted Benzenes 0.334 1,2,4-c16 trisubstituted benzenes 0.333 1,2,3-c16 trisubstituted 

benzenes

0.333 1,3,5-c16 trisubstituted 

benzenes

C19 Tetralin or Indan 1 Tetralin

C19 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

C20 Monosubstituted Benzenes 1 C16 Monosubstituted Benzenes

C20 Disubstituted Benzenes 0.334 m-c16 disubstituted benzenes 0.333 o-c16 disubstituted benzenes 0.333 p-c16 disubstituted benzenes

C20 Trisubstituted Benzenes 0.334 1,2,4-c16 trisubstituted benzenes 0.333 1,2,3-c16 trisubstituted 

benzenes

0.333 1,3,5-c16 trisubstituted 

benzenes

C20 Tetralin or Indan 1 Tetralin

C20 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

C21 Monosubstituted Benzenes 1 C16 Monosubstituted Benzenes

C21 Disubstituted Benzenes 0.334 m-c16 disubstituted benzenes 0.333 o-c16 disubstituted benzenes 0.333 p-c16 disubstituted benzenes

C21 Trisubstituted Benzenes 0.334 1,2,4-c16 trisubstituted benzenes 0.333 1,2,3-c16 trisubstituted 

benzenes

0.333 1,3,5-c16 trisubstituted

benzenes

C21 Tetralin or Indan 1 Tetralin

C21 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

C22 Monosubstituted Benzenes 1 C16 Monosubstituted Benzenes

C22 Disubstituted Benzenes 0.334 m-c16 disubstituted benzenes 0.333 o-c16 disubstituted benzenes 0.333 p-c16 disubstituted benzenes

C22 Trisubstituted Benzenes 0.334 1,2,4-c16 trisubstituted benzenes 0.333 1,2,3-c16 trisubstituted 

benzenes

0.333 1,3,5-c16 trisubstituted 

benzenes

C22 Tetralin or Indan 1 Tetralin

C22 Naphthalenes 0.5 Methyl Naphthalenes 0.5 2,3-Dimethyl Naphthalene

Peroxyacetic Acid 1 Acetic Acid

C4 aldehydes 1 Butanal

C5 Cyclic Ketones 1 Cyclopentanone

C5 Aldehydes 1 Pentanal (Valeraldehyde)

C5 Ketones 1 2-Pentanone

Phenol 1 o-Cresol
Table B-9 (continued)

266

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

2-Ethyl furan 1 2-methyl furan

C6 Cyclic Ketones 1 Cyclohexanone

mesityl oxide (2-methyl-2-penten4-one)1 Lumped product model species 

ISO-PROD

C6 Aldehydes 1 Hexanal

C6 Ketones 1 Methyl n-Butyl Ketone

C7 Alkyl Phenols 1 o-Cresol

m-Cresol 1 o-Cresol

p-Cresol 1 o-Cresol

C7 Cyclic Ketones 1 Cyclohexanone

C7 Aldehydes 1 Heptanal

C7 Ketones 1 2-Heptanone

Tolualdehyde 1 Benzaldehyde

4-vinylphenol 1 styrene

2,4-Dimethyl Phenol 1 o-Cresol

2,5-Dimethyl Phenol 1 o-Cresol

3,4-Dimethyl Phenol 1 o-Cresol

2,3-Dimethyl Phenol 1 o-Cresol

2,6-Dimethyl Phenol 1 o-Cresol

C8 Alkyl Phenols 1 o-Cresol

beta-phenethyl alcohol 1 benzyl alcohol

C8 Cyclic Ketones 1 Cyclohexanone

C8 Aldehydes 1 Octanal

C8 Ketones 1 2-Octanone

Hexyl Acetates 0.5 n-Hexyl Acetate 0.125 2-Methylpentyl Acetate

0.125 3-Methylpentyl Acetate 0.125 4-Methylpentyl Acetate 0.125 2,3-Dimethylbutyl Acetate

methylparaben (4-Hydroxybenzoic 

acid, methyl ester)

1 o-cresol

Cinnamic aldehyde 1 lumped c5+ unsaturated 

carbonyl species

Cinnamic alcohol 1 b-methyl styrene

2,3,5-Trimethyl Phenol 1 o-Cresol

2,3,6-Trimethyl Phenol 1 o-Cresol

C9 Alkyl Phenols 1 o-Cresol
Table B-9 (continued)

267

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

isophorone {3,5,5-trimethyl-2-

cyclohexenone}

1 Lumped product model species 

ISO-PROD

C9 Cyclic Ketones 1 Cyclohexanone

C9 Ketones 1 2-Nonanone

1-phenoxy-2-propanol 1 n-Propyl Benzene

Dipropylene glycol methyl ether 

acetate isomers

0.5 Dipropylene glycol methyl ether 

acetate isomer #1

0.5 Dipropylene glycol methyl 

ether acetate isomer #2

anethol 1 b-methyl styrene

C10 Alkyl Phenols 1 o-Cresol

C10 Cyclic Ketones 1 Cyclohexanone

C10 Ketones 1 2-Decanone

propylparaben 1 o-cresol

C11 Alkyl Phenols 1 o-Cresol

C12 Alkyl Phenols 1 o-Cresol

Texanol isomers 0.67 3-Hydroxy-2,2,4-

Trimethylpentyl-1-Isobutyrate

0.33 1-Hydroxy-2,2,4-

Trimethylpentyl-3-

Isobutyrate

Substituted C7 ester (C12) 0.67 3-Hydroxy-2,2,4-

Trimethylpentyl-1-Isobutyrate

0.33 1-Hydroxy-2,2,4-

Trimethylpentyl-3-

Isobutyrate

Substituted C9 Ester (C12) 0.67 3-Hydroxy-2,2,4-

Trimethylpentyl-1-Isobutyrate

0.33 1-Hydroxy-2,2,4-

Trimethylpentyl-3-

Isobutyrate

Amyl cinnamal 1 lumped c5+ unsaturated 

carbonyl species

isobornyl methacrylate 1 isobutyl methacrylate

Hexyl cinnamal 1 lumped c5+ unsaturated 

carbonyl species

2,6-di-tert-butyl-p-cresol 1 o-cresol

methyl cis-9-hexadecenoate 

(methyl palmitoleate)

1 methyl cis-9-pentadecenoate

methyl hexadecanoate; methyl 

palmitate

1 methyl pentadecanoate

Methyl cis-9-heptadecenoate 1 methyl cis-9-pentadecenoate
Table B-9 (continued)

268

Compound or Mixture Representation

Mol Compound Mol Compound Mol Compound

methyl heptadecanoate; methyl 

margarate

1 methyl pentadecanoate

methyl cis-9-octadecenoate; 

methyl oleate

1 methyl cis-9-pentadecenoate

methyl octadecanoate; methyl 

stearate

1 methyl pentadecanoate

Carbon Tetrachloride 1 Represented as inert

Methylene Bromide 1 Represented as inert

Cis-1,2-Dichloroethene 1 Trans-1,2-Dichloroethene

1,3-dichloropropene mixture 0.56 cis-1,3-dichloropropene 0.44 trans-1,3-dichloropropene

1-buten-3-yne (vinyl acetylene) 1 1-Butene

methyl nonafluoroisobutyl ether 1 methyl nonafluorobutyl ether

Methoxy perfluoro isobutane 1 Methoxy perfluoro n-butane

triethylene diamine 1 triethyl amine

o-dichlorobenzene 1 p-dichlorobenzene

ethyl nonafluoroisobutyl ether 1 ethyl nonafluorobutyl ether

Perfluorohexane 1 Represented as inert

2-chlorotoluene 1 toluene

3-(Chloromethyl)-Heptane 1 3-Methyl Heptane

2,6-Toluene Diisocyanate 1 2,4-Toluene Diisocyanate

Toluene Diisocyanate (mixed 

isomers)

1 2,4-Toluene Diisocyanate

lauryl pyrrolidone 1 n-methyl-2-pyrrolidone
269

Table B-10. Listing of components of complex mixtures for which atmospheric reactivities have been 

calculated. (Available in electronic form only) 

Because of the size of this table, it is only available in as 

supplementary material in electronic form. See Appendix D.

Table B-11. Assignments of explicitly represented compounds to lumped model species in the fixed 

parameter mechanism. (Available in electronic form only)

Because of the size of this table, it is only available in as 

supplementary material in electronic form. See Appendix D.
270

APPENDIX C. MECHANISM EVALUATION TABULATIONS AND PLOTS

This appendix contains the plots of the results of the model simulations of the environmental 

chamber experiments. The data presented in these plots are described in the "Data Presented" subsection 

of the "Mechanism Evaluation" section of the report. Reference is made to Table C-1, which contains the 

list of environmental chamber experiments used in this mechanism evaluation. Because of its size, this 

table is available only as supplementary material in the Excel file that also contains the tabulations in the 

other appendices to this report. This is described in Appendix D.

Table C-1. List of environmental chamber experiments used in the mechanism evaluation. . 

(Available in electronic form only)

Because of the size of this table, it is only available in as 

supplementary material in electronic form. See Appendix D.
271

Figure C-1. Plots of experimental and calculated environmental chamber reactivity results for carbon 

monoxide.

CTC105B ETC418 CTC123A DTC014A DTC015B DTC016A

CO CO CO CO CO CO

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC020B DTC029A ETC483 ETC487 EPA282A EPA283A

CO CO CO CO CO CO

IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-E MIR1 IR Surg-E MIR1 IR Surg-8 vary IR Surg-8 vary

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.00

1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

0.01

1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

0.01

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

0.01

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

0 1 2 3 4 5 6

-0.1

-0.1

0.0

0.0

0.0

0.0

1 2 3 4 5 6

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

1 2 3 4 5 6

-0.1

-0.1

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

1 2 3 4 5 6

-0.1

-0.1

-0.1

-0.1

0.0

0.0

0.0

0.0

0.0

0.0

0.0

1 2 3 4 5 6

-0.1

0.0

0.0

0.0

0.0

0.0

0.0

0.0

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

0.01

0.01

0.01

1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

0.01

0.01

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

0.01

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

0 1 2 3 4 5 6

-0.1

-0.1

0.0

0.0

0.0

0.0

0.0

1 2 3 4 5 6

-0.1

0.0

0.0

0.0

0.0

0.0

0.0

0.0

1 2 3 4 5 6

-0.2

-0.2

-0.1

-0.1

-0.1

-0.1

-0.1

0.0

0.0

0.0

1 2 3 4 5 6

-0.1

-0.1

-0.1

0.0

0.0

0.0

0.0

0.0

1 2 3 4 5 6

-0.1

-0.1

-0.1

0.0

0.0

0.0

0.0

0.0

0.1

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0 1 2 3 4 5 6

-0.1

-0.1

0.0

0.0

0.0

0.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

0.01

0.01

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6
272

Figure C-2. Plots of experimental and calculated environmental chamber reactivity results for ethane 

and propane

DTC242A ETC092 ETC099 ETC235 ETC506

ETHANE ETHANE ETHANE ETHANE ETHANE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-E MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

EPA292A EPA297B ETC226 ETC230 ETC305

ETHANE ETHANE PROPANE PROPANE PROPANE

IR Surg-8 vary IR Surg-8 vary IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.20

0.40

0.60

0.80

1.00

0 1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.00

0.01

0.01

0.01

1 2 3 4 5 6 0.00

0.00

0.00

0.00

0.00

0.00

0.01

0.01

0.01

0.01

0.01

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

0.01

0.01

0.01

0.01

1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.01

0.01

0.01

0.01

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

0.00

0.00

0.00

0.01

0.01

0.01

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 1 2 3 4 5 6

-0.01

0.00

0.01

0.01

0.02

0.02

0.03

0.03

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

1 2 3 4 5 6

-0.3

-0.2

-0.2

-0.1

-0.1

0.0

0.1

0.1

0.2

1 2 3 4 5 6

-0.2

-0.2

-0.1

-0.1

0.0

0.1

0.1

1 2 3 4 5 6

-0.2

-0.2

-0.1

-0.1

0.0

0.1

0.1

1 2 3 4 5 6

-0.4

-0.4

-0.3

-0.3

-0.2

-0.2

-0.1

-0.1

0.0

0.1

0.1

1 2 3 4 5 6

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 1 2 3 4 5 6

0.00

0.01

0.01

0.02

0.02

0.03

1 2 3 4 5 6

0.00

0.01

0.01

0.02

0.02

0.03

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

0.00

0.02

0.04

0.06

0.08

0.10

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.01

0.01

0.01

0.01

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0 1 2 3 4 5 6

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0 1 2 3 4 5 6

-0.3

-0.3

-0.2

-0.2

-0.1

-0.1

0.0

0.1

0.1

0 1 2 3 4 5 6
273

Figure C-3. Plots of experimental and calculated environmental chamber reactivity results for nbutane

ETC094 ETC097 ETC135 ETC224 DTC019B DTC031A

N-C4 N-C4 N-C4 N-C4 N-C4 N-C4

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

ETC389 ETC393 ETC484 ETC488

N-C4 N-C4 N-C4 N-C4

IR Surg-3 LN1 IR Surg-3 LN1 IR Surg-E MIR1 IR Surg-E MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.000

0.005

0.010

0.015

0.020

0.025

1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

0.05

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-2.0

-1.6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

2.0

0 1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

0.06

1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-6

-4

-2

0

1 2 3 4 5 6

-8

-6

-4

-2

0

2

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
274

Figure C-4. Plots of experimental and calculated environmental chamber reactivity results for nhexane and the Surg-3 MIR1 experiments for n-octane.

ETC201 ETC209 DTC072A CTC110B ETC237 ETC239

N-C6 N-C6 N-C6 N-C8 N-C8 N-C8

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-E MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 1 2 3 4 5 6

-0.14

-0.12

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

-0.16

-0.14

-0.12

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

-0.18

-0.16

-0.14

-0.12

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

-16.0

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

1 2 3 4 5 6

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

2.0

1 2 3 4 5 6

-16.0

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

2.0

1 2 3 4 5 6

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

1 2 3 4 5 6

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

2.0

1 2 3 4 5 6

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

2.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
275

Figure C-5. Plots of experimental and calculated environmental chamber reactivity results for noctane (excluding the Surg-3 MIR1 experiments, which are on Figure C-4).

CTC131A DTC024B DTC070A DTC037B DTC071B

N-C8 N-C8 N-C8 N-C8 N-C8

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

EPA114B EPA095A EPA083B EPA085B EPA113B

N-C8 N-C8 N-C8 N-C8 N-C8

IR Surg-8 MIR2 IR Surg-8 LN2 IR Surg-8 vary IR Surg-8 vary IR Surg-8 vary

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

-0.10

-0.05

0.00

0.05

0.10

0.15

1 2 3 4 5 6

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

0.10

0.12

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-0.10

-0.05

0.00

0.05

0.10

0.15

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0 1 2 3 4 5 6

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

1 2 3 4 5 6

-16.0

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

1 2 3 4 5 6

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

-35.0

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0 1 2 3 4 5 6

-300.0

-250.0

-200.0

-150.0

-100.0

-50.0

0.0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.15

-0.10

-0.05

0.00

0.05

0 1 2 3 4 5 6

-140.0

-120.0

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 1 2 3 4 5 6

-0.15

-0.10

-0.05

0.00

0.05

0.10

0 1 2 3 4 5 6

-140.0

-120.0

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 1 2 3 4 5 6

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0 1 2 3 4 5 6

-60.0

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0 1 2 3 4 5 6

-0.200

-0.150

-0.100

-0.050

0.000

0 1 2 3 4 5 6

-160.0

-140.0

-120.0

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
276

Figure C-6. Plots of experimental and calculated environmental chamber reactivity results for ndodecane.

DTC271B DTC273A DTC283B

N-C12 N-C12 N-C12

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

CTC150B CTC154A DTC272A DTC274B DTC284A DTC293A

N-C12 N-C12 N-C12 N-C12 N-C12 N-C12

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

1 2 3 4 5 6

-0.16

-0.14

-0.12

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-1.60

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

1 2 3 4 5 6

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0.15

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0 1 2 3 4 5 6

-70.0

-60.0

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

10.0

1 2 3 4 5 6

-8.0

-6.0

-4.0

-2.0

0.0

2.0

1 2 3 4 5 6

-70.0

-60.0

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

1 2 3 4 5 6

-35.0

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

1 2 3 4 5 6

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

-60.0

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

10.0

20.0

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0 1 2 3 4 5 6

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

1 2 3 4 5 6

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0 1 2 3 4 5 6

-0.35

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

1 2 3 4 5 6

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

1 2 3 4 5 6

-70.0

-60.0

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

1 2 3 4 5 6

-35.0

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
277

Figure C-7. Plots of experimental and calculated environmental chamber reactivity results for ntetradecane

DTC275A DTC277B DTC289B

N-C14 N-C14 N-C14

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

CTC151A CTC158A DTC276B DTC278A DTC290A

N-C14 N-C14 N-C14 N-C14 N-C14

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-2.00

-1.50

-1.00

-0.50

0.00

1 2 3 4 5 6

-2.50

-2.00

-1.50

-1.00

-0.50

0.00

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

0 1 2 3 4 5 6

-1.80

-1.60

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

1 2 3 4 5 6

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0 1 2 3 4 5 6

-0.40

-0.35

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0 1 2 3 4 5 6

-80.0

-60.0

-40.0

-20.0

0.0

20.0

1 2 3 4 5 6

-120.0

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

20.0

1 2 3 4 5 6

-70.0

-60.0

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

10.0

1 2 3 4 5 6

-35.0

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

-80.0

-70.0

-60.0

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

10.0

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0 1 2 3 4 5 6

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

0.40

1 2 3 4 5 6

-0.60

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0 1 2 3 4 5 6

-120.0

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

20.0

1 2 3 4 5 6

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
278

Figure C-8. Plots of experimental and calculated environmental chamber reactivity results for npentadecane and n-hexadecane.

DTC279B DTC280A

N-C15 N-C15

IR Surg-3 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC281B DTC282A DTC291B CTC152B CTC156B

N-C16 N-C16 N-C16 N-C16 N-C16

IR Surg-8 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-2.50

-2.00

-1.50

-1.00

-0.50

0.00

1 2 3 4 5 6

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0 1 2 3 4 5 6

-4.00

-3.50

-3.00

-2.50

-2.00

-1.50

-1.00

-0.50

0.00

1 2 3 4 5 6

-2.00

-1.50

-1.00

-0.50

0.00

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

0 1 2 3 4 5 6

-120.0

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

20.0

1 2 3 4 5 6

-140.0

-120.0

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

1 2 3 4 5 6

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

20.0

1 2 3 4 5 6

-80.0

-70.0

-60.0

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

10.0

1 2 3 4 5 6

-35.0

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

-35.0

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0 1 2 3 4 5 6

-0.80

-0.60

-0.40

-0.20

0.00

0.20

0.40

1 2 3 4 5 6

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
279

Figure C-9. Plots of experimental and calculated environmental chamber reactivity results for 

isobutane, 2,2,4-trimethyl pentane, and 2,6-dimethyl octane.

ETC228 ETC232 ETC241 ETC303 ETC291 ETC293

2-ME-C3 2-ME-C3 2-ME-C3 2-ME-C3 224TM-C5 224TM-C5

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC738B DTC747A DTC739A DTC733A DTC749A

26DM-C8 26DM-C8 26DM-C8 26DM-C8 26DM-C8

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-x MIR1 IR Surg-x MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.20

0.40

0.60

0.80

1.00

0 1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.00

0.01

0.01

0.02

0.02

0.03

0.03

0.04

0.04

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

1 2 3 4 5 6 -0.01

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

-0.02

-0.01

-0.01

0.00

0.01

0.01

0.02

0.02

0.03

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

-0.02

-0.01

-0.01

0.00

0.01

0.01

0.02

0.02

0.03

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

-4.0

-3.0

-2.0

-1.0

0.0

1.0

1 2 3 4 5 6

-0.8

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-1.4

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0 1 2 3 4 5 6

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

1 2 3 4 5 6

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0.15

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0 1 2 3 4 5 6

-0.15

-0.10

-0.05

0.00

0.05

0.10

1 2 3 4 5 6

-0.45

-0.40

-0.35

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

-0.60

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

1 2 3 4 5 6

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

-16.0

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

1 2 3 4 5 6

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
280

Figure C-10. Plots of experimental and calculated environmental chamber reactivity results for 2-

methyl nonane and 3,4-diethyl hexane.

DTC734B DTC741A DTC737A DTC746B DTC740B

2-ME-C9 2-ME-C9 2-ME-C9 2-ME-C9 2-ME-C9

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC726B DTC729B DTC732B DTC748B DTC725A DTC730A

34-DE-C6 34-DE-C6 34-DE-C6 34-DE-C6 34-DE-C6 34-DE-C6

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-x MIR1 IR Surg-x MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0.4

1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-16

-12

-8

-4

0

4

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

5

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

-20

-16

-12

-8

-4

0

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

-30

-20

-10

0

10

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-0.15

-0.10

-0.05

0.00

0.05

0.10

1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-8

-6

-4

-2

0

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
281

Figure C-11. Plots of experimental and calculated environmental chamber reactivity results for 

cyclohexane and hexyl cyclohexane.

DTC541A DTC551A DTC543B DTC552B DTC544A DTC553A

CYCC6 CYCC6 CYCC6 CYCC6 CYCC6 CYCC6

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC315B DTC318B CTC167A DTC317A DTC319B CTC233A

C6-CYCC6 C6-CYCC6 C6-CYCC6 C6-CYCC6 C6-CYCC6 C6-CYCC6

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.20

-0.15

-0.10

-0.05

0.00

0.05

1 2 3 4 5 6

-0.16

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.04

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

-0.04

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-10

-8

-6

-4

-2

0

1 2 3 4 5 6

-10

-8

-6

-4

-2

0

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

-2.0

-1.6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0.4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

0.1

0.2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-80

-60

-40

-20

0

1 2 3 4 5 6

-120

-80

-40

0

40

1 2 3 4 5 6

-30

-20

-10

0

1 2 3 4 5 6

-80

-60

-40

-20

0

1 2 3 4 5 6

-80

-60

-40

-20

0

1 2 3 4 5 6

-30

-20

-10

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
282

Figure C-12. Plots of experimental and calculated environmental chamber reactivity results for octyl 

cyclohexane.

CTC231A DTC324A CTC168B CTC232B CTC239B

C8-CYCC6 C8-CYCC6 C8-CYCC6 C8-CYCC6 C8-CYCC6

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

CTC240A DTC325B

C8-CYCC6 C8-CYCC6

IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

0.4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0.4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-60

-40

-20

0

20

1 2 3 4 5 6

-80

-60

-40

-20

0

20

1 2 3 4 5 6

-40

-30

-20

-10

0

1 2 3 4 5 6

-40

-30

-20

-10

0

10

1 2 3 4 5 6

-30

-20

-10

0

10

1 2 3 4 5 6

-30

-20

-10

0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-40

-30

-20

-10

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
283

Figure C-13. Plots of model errors in simulations of the ethene - NOx environmental chamber 

experiments. 

Ethene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

UCR Arc Light 10 -3% -2% -6% -5%

UCR Blacklight 29 24% 9% 22% 10%

TVA chamber 3 -6% 4% -16% -4%

OTC Chamber 7 -30% -22% -28% -23%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

UCR Arc Light

UCR Blacklight

TVA chamber

OTC Chamber

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
284

Figure C-14. Plots of experimental and calculated environmental chamber reactivity results for ethene.

ETC199 ETC203 DTC017A DTC038A

ETHENE ETHENE ETHENE ETHENE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-10

0

10

20

30

40

1 2 3 4 5 6

-20

0

20

40

60

1 2 3 4 5 6

-10

0

10

20

30

40

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
285

Figure C-15. Plots of model errors in simulations of the propene - NOx environmental chamber 

experiments. 

Propene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

UCR Arc Light 74 -9% -1% -8% 2%

UCR Blacklight 84 -5% -1% 5% 3%

TVA chamber 4 8% 13% 2% 6%

OTC Chamber 6 -19% 1% -3% 1%

UNC Chamber 20 58% 19% 61% 22%

Added CO 2 3% -12% 23% -5%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

UCR Arc Light

UCR Blacklight

TVA chamber

OTC Chamber

UNC Chamber

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
286

Figure C-16. Plots of experimental and calculated environmental chamber reactivity results for 

propene.

CTC142B ETC106 ETC108 ETC110 ETC118

PROPENE PROPENE PROPENE PROPENE PROPENE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

CTC130B DTC018A DTC032B ETC496 ETC500

PROPENE PROPENE PROPENE PROPENE PROPENE

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-E MIR1 IR Surg-E MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

0

1

2

3

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.5

1.0

1.5

2.0

2.5

1 2 3 4 5 6

0

1

2

3

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0

1

2

3

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-10

0

10

20

30

1 2 3 4 5 6

-40

-20

0

20

40

60

1 2 3 4 5 6

-20

0

20

40

60

1 2 3 4 5 6

-80

-40

0

40

80

1 2 3 4 5 6

-20

0

20

40

60

80

1 2 3 4 5 6

-5

0

5

10

15

20

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

2.0

1 2 3 4 5 6 -0.2

0.0

0.2

0.4

0.6

0.8

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-1

0

1

2

3

1 2 3 4 5 6

-1

0

1

2

3

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-10

0

10

20

30

40

1 2 3 4 5 6

-40

-30

-20

-10

0

10

1 2 3 4 5 6

-20

0

20

40

60

1 2 3 4 5 6

-40

0

40

80

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
287

Figure C-17. Plots of model errors in simulations of the 1-buteme and 1-hexene - NOx environmental 

chamber experiments. 

1-Butene - NOx and 1-Hexene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

1-Butene, Black 3 18% -1% 7% -9%

1-Butene, Arc 3 -11% -8% -34% -22%

1-Hexene, Black 3 1% 15% 16% 17%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

1-Butene, Black

1-Butene, Arc

1-Hexene, Black

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
288

Figure C-18. Plots of model errors in simulations of the trans-2-butene and isobutene - NOx

environmental chamber experiments. 

Trans-2-Butene - NOx and Isobutene - NOx

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Isobutene, Black 2 0% 13% -7% 9%

Trans-2-Butene, TVA 3 1% 8% 0% 3%

Trans-2-Butene, EC 3 5% 1% 8% 0%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Isobutene, Black

Trans-2-Butene,

TVA

Trans-2-Butene, EC

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
289

Figure C-19. Plots of experimental and calculated environmental chamber reactivity results for 

isobutene and trans-2-butene.

ETC253 ETC255 ETC257 ETC307 ETC309 DTC021B

ISOBUTEN ISOBUTEN ISOBUTEN T-2-BUTE T-2-BUTE T-2-BUTE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC069A DTC033A DTC041A DTC043B ETC493 ETC501

T-2-BUTE T-2-BUTE T-2-BUTE T-2-BUTE T-2-BUTE T-2-BUTE

IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-E LN1 IR Surg-E MIR1 IR Surg-E MIR1 IR Surg-E MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0

1

2

3

1 2 3 4 5 6

0

1

2

3

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0

1

2

3

4

1 2 3 4 5 6

0

2

4

6

8

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0

2

4

6

8

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.5

1.0

1.5

2.0

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0

20

40

60

80

100

1 2 3 4 5 6 -40

0

40

80

120

1 2 3 4 5 6

-40

0

40

80

120

1 2 3 4 5 6 0

50

100

150

200

250

1 2 3 4 5 6

0

50

100

150

200

250

1 2 3 4 5 6

0

10

20

30

40

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.5

1.0

1.5

2.0

2.5

1 2 3 4 5 6 -0.8

-0.4

0.0

0.4

0.8

1.2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-4

-2

0

2

4

6

8

1 2 3 4 5 6

0

2

4

6

8

10

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-2

0

2

4

6

8

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-4

0

4

8

12

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0

20

40

60

1 2 3 4 5 6 -60

-40

-20

0

20

40

1 2 3 4 5 6

-100

0

100

200

1 2 3 4 5 6

0

100

200

300

1 2 3 4 5 6

0

50

100

150

200

1 2 3 4 5 6 -100

0

100

200

300

400

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
290

Figure C-20. Plots of model errors in simulations of the isoprene - NOx environmental chamber 

experiments. 

Isoprene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 3 -4% -5% -9% -8%

Blacklight 6 -6% -7% -11% -11%

EC Chamber 5 8% 19% -7% 12%

OTC Chamber 4 -3% -1% -4% -2%

UNC Chamber 10 -2% 1% -1% 4%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

EC Chamber

OTC Chamber

UNC Chamber

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
291

Figure C-21. Plots of experimental and calculated environmental chamber reactivity results for 

isoprene

ETC271 ETC273 ETC275 ETC277 DTC046A DTC050B

ISOPRENE ISOPRENE ISOPRENE ISOPRENE ISOPRENE ISOPRENE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-E LN1 IR Surg-E LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC047B ETC495 ETC503 ETC510

ISOPRENE ISOPRENE ISOPRENE ISOPRENE

IR Surg-E MIR1 IR Surg-E MIR1 IR Surg-E MIR1 IR Surg-E MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0

1

2

3

4

1 2 3 4 5 6

0

1

2

3

4

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0

1

2

3

4

5

1 2 3 4 5 6

0

2

4

6

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-2

-1

0

1

2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-2

-1

0

1

2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-20

0

20

40

60

80

1 2 3 4 5 6

-20

0

20

40

60

80

1 2 3 4 5 6

-40

0

40

80

120

1 2 3 4 5 6

-40

0

40

80

120

1 2 3 4 5 6

-80

-40

0

40

80

1 2 3 4 5 6

-120

-80

-40

0

40

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0

2

4

6

1 2 3 4 5 6 -1

0

1

2

3

4

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-1

0

1

2

3

1 2 3 4 5 6

-1

0

1

2

3

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-100

-50

0

50

100

150

1 2 3 4 5 6

-40

-20

0

20

40

60

1 2 3 4 5 6

-40

0

40

80

120

1 2 3 4 5 6

-40

-20

0

20

40

60

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
292

Figure C-22. Plots of model errors in simulations of the terpene - NOx environmental chamber 

experiments. 

Terpene - NOx Experiments

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

a-Pinene 6 6% 2% 1% -1%

b-Pinene 6 -8% 44% -13% 41%

d-Limonene 7 -7% -6% -2% -4%

Sabinene 3 54% 3% 6% 4%

3-Carene 4 -12% -15% -9% -22%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

a-Pinene

b-Pinene

d-Limonene

Sabinene

3-Carene

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
293

Figure C-23. Plots of experimental and calculated environmental chamber reactivity results for - and 

-pinene and d-limonene.

DTC034B DTC044A DTC045B ETC508 DTC048A DTC051B

A-PINENE A-PINENE A-PINENE A-PINENE B-PINENE B-PINENE

IR Surg-8 LN1 IR Surg-E LN1 IR Surg-E MIR1 IR Surg-E MIR1 IR Surg-E LN1 IR Surg-E MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-0.8

-0.4

0.0

0.4

0.8

1 2 3 4 5 6

-4

-2

0

2

4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0

2

4

6

1 2 3 4 5 6 -2

0

2

4

6

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-1.0

-0.5

0.0

0.5

1.0

1.5

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

2.0

0 1 2 3 4 5 6

-80

-60

-40

-20

0

20

1 2 3 4 5 6

-150

-100

-50

0

50

100

1 2 3 4 5 6

-50

0

50

100

150

200

1 2 3 4 5 6

-40

0

40

80

120

1 2 3 4 5 6

-200

-150

-100

-50

0

50

1 2 3 4 5 6

-120

-80

-40

0

40

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

EPA793A EPA797A EPA804A

D-LIMONE D-LIMONE D-LIMONE

IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 LN2

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0 1 2 3 4 5 6

-0.50

0.00

0.50

1.00

1.50

2.00

0 1 2 3 4 5 6

-150.0

-100.0

-50.0

0.0

50.0

100.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 1 2 3 4 5 6

-0.40

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 1 2 3 4 5 6

-600.0

-500.0

-400.0

-300.0

-200.0

-100.0

0.0

100.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 1 2 3 4 5 6

-0.60

-0.40

-0.20

0.00

0.20

0.40

0.60

0.80

0 1 2 3 4 5 6

-500.0

-400.0

-300.0

-200.0

-100.0

0.0

100.0

200.0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc
294

Figure C-24. Plots of experimental and calculated environmental chamber reactivity results for 

cyclohexene.

Figure C-25. Plots of experimental and calculated environmental chamber reactivity results for styrene.

EPA408B CYC-HEXE NA surg

(O3-NO) (ppm) IR (O3-NO) (mole basis) IR IntOH (ppt-min/ppm) Cyclohexene (ppm)

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6 -200

-100

0

100

200

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc

0.00

0.02

0.04

0.06

0 1 2 3 4 5 6

CTC246A CTC250B CTC248B CTC251A CTC249A CTC253B

STYRENE STYRENE STYRENE STYRENE STYRENE STYRENE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

1 2 3 4 5 6

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0.2

1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0.2

0.3

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-30

-20

-10

0

10

1 2 3 4 5 6

-60

-40

-20

0

20

1 2 3 4 5 6

-30

-20

-10

0

10

1 2 3 4 5 6

-20

-15

-10

-5

0

5

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

-40

-30

-20

-10

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
295

Figure C-26. Plots of model errors in simulations of the benzene and benzene + CO - NOx

environmental chamber experiments. 

Benzene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 4 58% 12% 42% 6%

Blacklight 4 -30% 18% -31% 3%

Added CO 1 -68% -29% -60% -32%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-75%

-50%

-25%

0%

25%

50%

75%

1 2 3 4 5 6

-75%

-50%

-25%

0%

25%

50%

75%

1 2 3 4 5 6

Arc Light

Blacklight

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
296

Figure C-27. Plots of experimental and calculated environmental chamber reactivity results for 

benzene.

ETC263 ETC265 DTC039B EPA421B

BENZENE BENZENE BENZENE BENZENE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 LN1 IR Surg-NA vary

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

1 2 3 4 5 6

-0.5

0.0

0.5

1.0

1.5

2.0

1 2 3 4 5 6

-1

0

1

2

3

1 2 3 4 5 6

-4

-3

-2

-1

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6

-10

0

10

20

30

0 1 2 3 4 5 6
297

Figure C-28. Plots of model errors in simulations of the toluene and toluene + CO - NOx

environmental chamber experiments. 

Toluene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 22 3% 11% -13% 7%

Blacklight 19 -7% -3% 28% 2%

TVA chamber 3 -3% -2% -5% 1%

OTC Chamber 4 -4% 7% -11% 15%

UNC Chamber 5 53% 68% 27% 88%

Added CO 7 -20% -19% -18% -13%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

75%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

75%

1 2 3 4 5 6

Arc Light

Blacklight

TVA chamber

OTC Chamber

UNC Chamber

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
298

Figure C-29. Plots of model errors in simulations of the ethylbenzene - NOx environmental chamber 

experiments. 

Ethylbenzene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 4 5% 5% -18% 14%

Blacklight 4 16% -10% -3% -10%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
299

Figure C-30. Plots of experimental and calculated environmental chamber reactivity results for toluene 

and ethylbenzene.

CTC108B ETC101 ETC103 CTC127B DTC023A DTC030B

TOLUENE TOLUENE TOLUENE TOLUENE TOLUENE TOLUENE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

ETC311 ETC313 ETC315

C2-BENZ C2-BENZ C2-BENZ

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1 2 3 4 5 6 -0.4

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0.2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-10

0

10

20

30

1 2 3 4 5 6

-20

0

20

40

60

1 2 3 4 5 6

-20

0

20

40

60

1 2 3 4 5 6 0

4

8

12

16

1 2 3 4 5 6

0

10

20

30

40

1 2 3 4 5 6 -20

-15

-10

-5

0

5

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.4

0.0

0.4

0.8

1.2

1 2 3 4 5 6

-0.4

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.4

0.0

0.4

0.8

1.2

1 2 3 4 5 6

-40

-20

0

20

40

60

1 2 3 4 5 6

-60

-40

-20

0

20

40

1 2 3 4 5 6

-20

-10

0

10

20

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
300

Figure C-31. Plots of model errors in simulations of the m-xylene and m-xylene + CO - NOx

environmental chamber experiments. 

M-Xylene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 20 24% 7% -2% -6%

Blacklight 36 4% 5% 4% -6%

TVA chamber 2 -7% -1% -14% -9%

Added CO 6 -24% -23% -2% -17%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

TVA chamber

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
301

Figure C-32. Plots of model errors in simulations of the o-xylene - NOx environmental chamber 

experiments. 

O-Xylene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 6 15% 4% -2% -6%

Blacklight 6 10% -3% -3% -12%

EC Chamber 2 -1% 7% -15% 1%

UNC Chamber 4 54% 16% 45% 24%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

EC Chamber

UNC Chamber

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
302

Figure C-33. Plots of model errors in simulations of the p-xylene - NOx environmental chamber 

experiments. 

P-Xylene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 6 52% -10% 6% 6%

Blacklight 7 10% -15% -3% -4%

Added CO 1 -38% -30% -54% -27%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
303

Figure C-34. Plots of experimental and calculated environmental chamber reactivity results for mxylene (additional experiments shown on Figure C-35).

CTC109A ETC196 ETC207 ETC301 CTC128A DTC025A

M-XYLENE M-XYLENE M-XYLENE M-XYLENE M-XYLENE M-XYLENE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC068B DTC035A DTC067B EPA110A EPA123B

M-XYLENE M-XYLENE M-XYLENE M-XYLENE M-XYLENE

IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-8 MIR2 IR Surg-8 LN2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0

1

2

3

4

1 2 3 4 5 6 -2

0

2

4

6

8

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0

2

4

6

8

1 2 3 4 5 6 -2

0

2

4

6

8

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.5

1.0

1.5

2.0

2.5

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0

1

2

3

4

5

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-40

0

40

80

120

1 2 3 4 5 6

-100

0

100

200

300

1 2 3 4 5 6 0

50

100

150

200

250

1 2 3 4 5 6 -100

0

100

200

300

1 2 3 4 5 6

-20

0

20

40

60

80

100

1 2 3 4 5 6

0

50

100

150

200

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0

2

4

6

1 2 3 4 5 6 -1.0

-0.5

0.0

0.5

1.0

1.5

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.8

-0.4

0.0

0.4

0.8

1.2

1 2 3 4 5 6

-40

0

40

80

120

160

1 2 3 4 5 6

-120

-80

-40

0

40

80

1 2 3 4 5 6

-120

-80

-40

0

40

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-2

0

2

4

6

0 1 2 3 4 5 6

-800

-400

0

400

800

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-1.5

-1.0

-0.5

0.0

0.5

1.0

0 1 2 3 4 5 6

-400

-300

-200

-100

0

100

0 1 2 3 4 5 6
304

Figure C-35. Plots of experimental and calculated environmental chamber reactivity results for mxylene (with variable surrogate conditions), o-xylene, and p-xylene.

EPA084A EPA086B EPA100B EPA108A EPA128B EPA406B

M-XYLENE M-XYLENE M-XYLENE M-XYLENE M-XYLENE M-XYLENE

IR Surg-8 vary IR Surg-8 vary IR Surg-8 vary IR Surg-8 vary IR Surg-8 vary IR Surg-NA vary

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

ETC259 ETC261 ETC348 EPA422A

O-XYLENE O-XYLENE P-XYLENE P-XYLENE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 VOC - CO - NOx

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0

2

4

6

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0

2

4

6

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-1

0

1

2

3

4

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-50

0

50

100

150

200

1 2 3 4 5 6

-50

0

50

100

150

200

1 2 3 4 5 6

-40

0

40

80

120

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-1

0

1

2

3

0 1 2 3 4 5 6

-400

-300

-200

-100

0

100

200

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6

-0.8

-0.4

0.0

0.4

0 1 2 3 4 5 6

-300

-200

-100

0

100

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0 1 2 3 4 5 6

-1.5

-1.0

-0.5

0.0

0.5

1.0

0 1 2 3 4 5 6

-1200

-800

-400

0

400

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

0

2

4

6

8

0 1 2 3 4 5 6

-400

0

400

800

1200

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0 1 2 3 4 5 6

-2

0

2

4

6

0 1 2 3 4 5 6

-500

0

500

1000

1500

2000

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-2

0

2

4

6

0 1 2 3 4 5 6

-400

0

400

800

1200

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

0 1 2 3 4 5 6

-16

-12

-8

-4

0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
305

Figure C-36. Plots of model errors in simulations of the 1,2,3-trimethylbenzene - NOx environmental 

chamber experiments. 

123-TMB - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 4 1% -1% 9% 1%

Blacklight 5 2% -8% 6% -5%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
306

Figure C-37. Plots of model errors in simulations of the 1,2,4-trimethylbenzene - NOx environmental 

chamber experiments. 

124-TMB - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 4 23% -2% 5% 14%

Blacklight 6 17% -9% -5% -8%

Added CO 1 -8% -19% -36% -21%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
307

Figure C-38. Plots of model errors in simulations of the 1,3,5-trimethylbenzene and 1,3,5-

trimethylbenzene + CO - NOx environmental chamber experiments. 

135-TMB - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 5 0% 3% 1% 5%

Blacklight 12 0% 0% -2% 1%

EC Chamber 2 21% 33% 14% 35%

Added CO 2 0% -15% -1% -7%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

EC Chamber

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
308

Figure C-39. Plots of experimental and calculated environmental chamber reactivity results for 1,2,3-, 

1,2,4- and 1,3,4-trimethylbenzenes.

ETC297 ETC299 ETC267 ETC269 ETC249

123-TMB 123-TMB 124-TMB 124-TMB 135-TMB

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0

4

8

12

1 2 3 4 5 6

0

4

8

12

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0

2

4

6

8

10

1 2 3 4 5 6

0

2

4

6

8

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0

10

20

30

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-100

0

100

200

300

400

500

1 2 3 4 5 6

-200

0

200

400

600

1 2 3 4 5 6

-100

0

100

200

300

1 2 3 4 5 6

-100

0

100

200

300

1 2 3 4 5 6

-200

0

200

400

600

800

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
309

Figure C-40. Plots of model errors in simulations of the naphthalene, 2,3-dimethylnaphthalene, and 

tetralin - NOx environmental chamber experiments. 

Naphtlanenes and Tetralin NOx Experiments

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Naphthalene 5 15% 5% 17% 3%

Tetralin 5 -14% 7% 4% 16%

2,3-Dime.naphth. 4 14% 0% 10% -2%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Naphthalene

Tetralin

2,3-Dime.naphth.

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
310

Figure C-41. Plots of model errors in simulations of the acetylene - NOx environmental chamber 

experiments. 

Acetyllene - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 2 25% -5% -35% -23%

Blacklight 2 2% 2% -16% -19%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
311

Figure C-42. Plots of experimental and calculated environmental chamber reactivity results for 

acetylene.

CTC184B CTC185A CTC192A CTC186B CTC193B

ACETYLEN ACETYLEN ACETYLEN ACETYLEN ACETYLEN

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

CTC187A CTC194A

ACETYLEN ACETYLEN

IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.002

0.000

0.002

0.004

0.006

0.008

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.4

0.0

0.4

0.8

1.2

1 2 3 4 5 6 0.0

0.4

0.8

1.2

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

2.0

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0.4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.002

0.000

0.002

0.004

0.006

1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0.2

0.3

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
312

Figure C-43. Plots of experimental and calculated environmental chamber reactivity results for 

methanol and ethanol.

ETC285 ETC287 ETC289 ETC131 ETC133 ETC138

MEOH MEOH MEOH ETOH ETOH ETOH

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6 -0.04

-0.02

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.4

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

-6

-4

-2

0

2

4

1 2 3 4 5 6

-2

-1

0

1

2

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

0.8

1.2

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

0.8

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

0.8

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
313

Figure C-44. Plots of experimental and calculated environmental chamber reactivity results for 

isopropyl alcohol.

DTC395A DTC398B ETC148 ETC155 ETC157 ETC159

I-C3-OH I-C3-OH I-C3-OH I-C3-OH I-C3-OH I-C3-OH

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC396B DTC399A DTC397A DTC400B

I-C3-OH I-C3-OH I-C3-OH I-C3-OH

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.04

0.00

0.04

0.08

0.12

0.16

0.20

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.8

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-2

-1

0

1

2

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

0.8

1.2

1 2 3 4 5 6

-2

0

2

4

6

1 2 3 4 5 6

-4

0

4

8

1 2 3 4 5 6

-4

-2

0

2

4

6

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

0.05

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

0.8

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

-3

-2

-1

0

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
314

Figure C-45. Plots of experimental and calculated environmental chamber reactivity results for t-butyl 

alcohol.

DTC233A DTC241B DTC249A DTC256A

T-C4-OH T-C4-OH T-C4-OH T-C4-OH

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC259A DTC268A DTC269A

T-C4-OH T-C4-OH T-C4-OH

IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-0.01

0.00

0.01

0.02

0.03

1 2 3 4 5 6

-0.004

0.000

0.004

0.008

0.012

0.016

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.000

0.005

0.010

0.015

0.020

0.025

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.000

0.004

0.008

0.012

0.016

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-0.8

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

0.8

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
315

Figure C-46. Plots of experimental and calculated environmental chamber reactivity results for 1-, 2-, 

and 3-octanol.

DTC508B DTC529A DTC509A DTC519B

1-C8-OH 1-C8-OH 1-C8-OH 1-C8-OH

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC517A DTC521B DTC524B DTC514B DTC516B DTC520A

2-C8-OH 2-C8-OH 2-C8-OH 3-C8-OH 3-C8-OH 3-C8-OH

IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

1 2 3 4 5 6

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.2

0.0

0.2

0.4

0.6

1 2 3 4 5 6

-0.1

0.0

0.1

0.2

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.1

0.0

0.1

0.2

0.3

0.4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

-80

-60

-40

-20

0

20

1 2 3 4 5 6

-60

-40

-20

0

20

1 2 3 4 5 6

-40

-30

-20

-10

0

1 2 3 4 5 6

-40

-30

-20

-10

0

10

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.05

0.00

0.05

0.10

0.15

0.20

1 2 3 4 5 6

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.2

0.0

0.2

0.4

0.6

1 2 3 4 5 6 0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-30

-20

-10

0

1 2 3 4 5 6

-60

-40

-20

0

20

1 2 3 4 5 6

-40

-30

-20

-10

0

1 2 3 4 5 6

-40

-30

-20

-10

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
316

Figure C-47. Plots of experimental and calculated environmental chamber reactivity results for 

ethylene glycol.

EPA278B EPA250B EPA253A EPA258B EPA415B

ET-GLYCL ET-GLYCL ET-GLYCL ET-GLYCL ET-GLYCL

IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-7 LN2 IR Surg-8 vary IR Surg-NA vary

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.1

0.2

0.3

0 1 2 3 4 5 6

-0.1

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-120

-80

-40

0

40

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0 1 2 3 4 5 6

-0.05

0.00

0.05

0.10

0.15

0 1 2 3 4 5 6

-50

-40

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-40

-30

-20

-10

0

10

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0 1 2 3 4 5 6

-0.05

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-60

-40

-20

0

20

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-40

-20

0

20

40

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc
317

Figure C-48. Plots of experimental and calculated environmental chamber reactivity results for 

propylene glycol.

DTC385A DTC389B DTC386B DTC390A DTC388A DTC391B

PR-GLYCL PR-GLYCL PR-GLYCL PR-GLYCL PR-GLYCL PR-GLYCL

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

EPA257B EPA273A EPA277A EPA245B EPA252A EPA404B

PR-GLYCL PR-GLYCL PR-GLYCL PR-GLYCL PR-GLYCL PR-GLYCL

IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-7 LN2 IR Surg-NA vary

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

1 2 3 4 5 6

0.0

0.1

0.2

0.3

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0.20

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-2.0

-1.6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-4

-2

0

2

4

6

1 2 3 4 5 6

-8

-4

0

4

8

1 2 3 4 5 6

-10

-8

-6

-4

-2

0

1 2 3 4 5 6

-16

-12

-8

-4

0

4

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

0.0

0.1

0.2

0.3

0 1 2 3 4 5 6

-0.1

0.0

0.1

0.2

0.3

0 1 2 3 4 5 6

-120

-80

-40

0

40

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-120

-80

-40

0

40

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0 1 2 3 4 5 6

-0.1

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-300

-200

-100

0

100

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0 1 2 3 4 5 6

-0.05

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-60

-40

-20

0

20

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-60

-40

-20

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.2

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-40

-20

0

20

40

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
318

Figure C-49. Plots of experimental and calculated environmental chamber reactivity results for 

dimethyl ether and diethyl ether.

ETC279 ETC281 ETC283 ETC295

ME-O-ME ME-O-ME ME-O-ME ME-O-ME

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC510B DTC522A DTC511A DTC515A DTC513A DTC525A

ET-O-ET ET-O-ET ET-O-ET ET-O-ET ET-O-ET ET-O-ET

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0.20

1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

0.8

1 2 3 4 5 6

-1.5

-1.0

-0.5

0.0

0.5

1.0

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-16

-12

-8

-4

0

4

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-8

-6

-4

-2

0

2

1 2 3 4 5 6

-15

-10

-5

0

5

10

1 2 3 4 5 6

-20

-15

-10

-5

0

1 2 3 4 5 6

-30

-20

-10

0

10

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
319

Figure C-50. Plots of experimental and calculated environmental chamber reactivity results for methyl 

t-butyl ether.

ETC120 ETC123 ETC125 ETC127

MTBE MTBE MTBE MTBE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-2

-1

0

1

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
320

Figure C-51. Plots of experimental and calculated environmental chamber reactivity results for 1-

methoxy-2-propanol.

DTC489A DTC495A DTC492A DTC500A DTC496B DTC501B

MEOC3OH MEOC3OH MEOC3OH MEOC3OH MEOC3OH MEOC3OH

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

0.0

0.1

0.2

0.3

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

1 2 3 4 5 6

0.0

0.2

0.4

0.6

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0.20

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-8

-6

-4

-2

0

2

1 2 3 4 5 6

-12

-8

-4

0

4

8

1 2 3 4 5 6

-16

-12

-8

-4

0

4

1 2 3 4 5 6

-20

-15

-10

-5

0

5

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

-30

-20

-10

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
321

Figure C-52. Plots of experimental and calculated environmental chamber reactivity results for 2-

ethoxyethanol and 2-(2-ethoxyethoxy) ethanol (DGEE).

ETC163 ETC171 ETC175 ETC166 ETC169 ETC173

ETO-ETOH ETO-ETOH ETO-ETOH DGEE DGEE DGEE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6 -0.2

0.0

0.2

0.4

0.6

0.8

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-0.2

0.0

0.2

0.4

0.6

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.2

0.0

0.2

0.4

0.6

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-6

-4

-2

0

2

4

1 2 3 4 5 6

-8

-4

0

4

8

1 2 3 4 5 6

-15

-10

-5

0

5

1 2 3 4 5 6

-40

-30

-20

-10

0

10

1 2 3 4 5 6

-40

-30

-20

-10

0

10

1 2 3 4 5 6

-20

-15

-10

-5

0

5

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
322

Figure C-53. Plots of experimental and calculated environmental chamber reactivity results for 2-

butoxyethanol.

DTC491B DTC498B DTC505B DTC493B DTC502A

BUO-ETOH BUO-ETOH BUO-ETOH BUO-ETOH BUO-ETOH

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC497A DTC506A

BUO-ETOH BUO-ETOH

IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

0.08

1 2 3 4 5 6

-0.04

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.10

-0.05

0.00

0.05

0.10

0.15

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-16

-12

-8

-4

0

4

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-20

-16

-12

-8

-4

0

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

1 2 3 4 5 6

-30

-20

-10

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
323

Figure C-54. Plots of experimental and calculated environmental chamber reactivity results for 2-(2-

butoxyethoxy)-ethanol.

EPA352B EPA335A EPA353B

DGBE DGBE DGBE

IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-7 LN2

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

0.4

0 1 2 3 4 5 6

-800

-600

-400

-200

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

0.4

0 1 2 3 4 5 6

-400

-300

-200

-100

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

0.4

0 1 2 3 4 5 6

-400

-300

-200

-100

0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc
324

Figure C-55. Plots of experimental and calculated environmental chamber reactivity results for methyl 

acetate.

DTC327A DTC328B DTC336A

ME-ACET ME-ACET ME-ACET

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC332A DTC335B DTC329A DTC330B

ME-ACET ME-ACET ME-ACET ME-ACET

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.004

0.000

0.004

0.008

0.012

1 2 3 4 5 6 0.000

0.004

0.008

0.012

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.000

0.002

0.004

0.006

0.008

1 2 3 4 5 6

0.000

0.002

0.004

0.006

0.008

0.010

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.000

0.005

0.010

0.015

0.020

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.000

0.002

0.004

0.006

0.008

0.010

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0.4

0.6

1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

0.1

0.2

1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0.4

1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.000

0.004

0.008

0.012

1 2 3 4 5 6

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
325

Figure C-56. Plots of experimental and calculated environmental chamber reactivity results for ethyl 

acetate.

DTC358A DTC362B DTC364B DTC359B DTC408B

ET-ACET ET-ACET ET-ACET ET-ACET ET-ACET

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

CTC195B DTC394A DTC409A DTC415B

ET-ACET ET-ACET ET-ACET ET-ACET

IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-3 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

-0.08

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.08

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

-0.012

-0.008

-0.004

0.000

0.004

0.008

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.008

-0.004

0.000

0.004

0.008

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.016

-0.012

-0.008

-0.004

0.000

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-3

-2

-1

0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.012

-0.008

-0.004

0.000

0.004

1 2 3 4 5 6

-0.008

-0.006

-0.004

-0.002

0.000

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
326

Figure C-57. Plots of experimental and calculated environmental chamber reactivity results for 

isopropyl and t-butyl acetates.

DTC688B DTC689A DTC697A

IPR-ACET IPR-ACET IPR-ACET

IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

CTC216B CTC221A CTC217A CTC222B CTC220B CTC223A

TBU-ACET TBU-ACET TBU-ACET TBU-ACET TBU-ACET TBU-ACET

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

-0.004

-0.002

0.000

0.002

0.004

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.004

-0.002

0.000

0.002

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.000

0.005

0.010

0.015

0.020

0.025

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-2

-1

0

1

2

1 2 3 4 5 6

-0.8

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.000

0.002

0.004

0.006

0.008

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.000

0.002

0.004

0.006

0.008

1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
327

Figure C-58. Plots of experimental and calculated environmental chamber reactivity results for methyl 

isobutyrate.

DTC528B DTC533A DTC530B DTC534B

ME-IBUAT ME-IBUAT ME-IBUAT ME-IBUAT

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC531A DTC539A DTC548A

ME-IBUAT ME-IBUAT ME-IBUAT

IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

-0.08

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

1 2 3 4 5 6 -0.01

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.010

-0.005

0.000

0.005

0.010

0.015

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.008

-0.004

0.000

0.004

0.008

0.012

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-4

-3

-2

-1

0

1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-3

-2

-1

0

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-4

-3

-2

-1

0

1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.008

-0.004

0.000

0.004

0.008

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
328

Figure C-59. Plots of experimental and calculated environmental chamber reactivity results for methyl 

pivalate.

DTC694A DTC701B DTC695B DTC702A DTC700A DTC707B

ME-PVAT ME-PVAT ME-PVAT ME-PVAT ME-PVAT ME-PVAT

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.03

-0.02

-0.01

0.00

0.01

1 2 3 4 5 6

-0.020

-0.016

-0.012

-0.008

-0.004

0.000

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.004

0.000

0.004

0.008

0.012

1 2 3 4 5 6

-0.004

0.000

0.004

0.008

0.012

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.004

-0.002

0.000

0.002

0.004

0.006

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.004

-0.002

0.000

0.002

0.004

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-0.8

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-2.0

-1.6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

1 2 3 4 5 6

-0.8

-0.6

-0.4

-0.2

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
329

Figure C-60. Plots of experimental and calculated environmental chamber reactivity results for n-butyl 

acetate.

CTC196A DTC365A DTC368B DTC402B

BU-ACET BU-ACET BU-ACET BU-ACET

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC403A DTC410B DTC406A DTC411A

BU-ACET BU-ACET BU-ACET BU-ACET

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-3

-2

-1

0

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

-3

-2

-1

0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.000

0.004

0.008

0.012

0.016

0.020

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-6

-4

-2

0

1 2 3 4 5 6

-3

-2

-1

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
330

Figure C-61. Plots of experimental and calculated environmental chamber reactivity results for 

dimethyl carbonate and methyl isopropyl carbonate.

DTC692B DTC703B DTC693A DTC705A DTC698B

DMC DMC DMC DMC DMC

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC750B DTC759A DTC755A DTC762A DTC758B DTC763B

MIPR-CB MIPR-CB MIPR-CB MIPR-CB MIPR-CB MIPR-CB

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.000

0.002

0.004

0.006

0.008

1 2 3 4 5 6

0.000

0.002

0.004

0.006

0.008

0.010

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.000

0.004

0.008

0.012

0.016

1 2 3 4 5 6

0.000

0.004

0.008

0.012

0.016

0.020

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.000

0.002

0.004

0.006

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

0.04

1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0.20

1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

0.05

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

0.05

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-4

-3

-2

-1

0

1 2 3 4 5 6

-6

-4

-2

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
331

Figure C-62. Plots of experimental and calculated environmental chamber reactivity results for 

propylene carbonate.

DTC235B DTC239B DTC243A DTC264B

PC PC PC PC

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC250B DTC260B DTC266A

PC PC PC

IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.03

-0.02

-0.01

0.00

0.01

0.02

1 2 3 4 5 6

-0.016

-0.012

-0.008

-0.004

0.000

0.004

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.008

-0.004

0.000

0.004

0.008

1 2 3 4 5 6

-0.012

-0.008

-0.004

0.000

0.004

0.008

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.000

0.005

0.010

0.015

0.020

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-1.5

-1.0

-0.5

0.0

0.5

1.0

1 2 3 4 5 6

-0.8

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-20

-16

-12

-8

-4

0

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.000

0.004

0.008

0.012

0.016

1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
332

Figure C-63. Plots of experimental and calculated environmental chamber reactivity results for 1-

methoxy-2-propyl acetate.

DTC532B DTC537A DTC549B DTC538B DTC547B DTC540B

PGME-ACT PGME-ACT PGME-ACT PGME-ACT PGME-ACT PGME-ACT

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0.20

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.04

0.00

0.04

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-30

-20

-10

0

10

1 2 3 4 5 6

-30

-20

-10

0

10

1 2 3 4 5 6

-20

-15

-10

-5

0

5

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
333

Figure C-64. Plots of experimental and calculated environmental chamber reactivity results for 

dimethyl succinate and dimethyl glutarate.

CTC197B CTC211B CTC198A CTC208A CTC199B CTC210A

DBE-4 DBE-4 DBE-4 DBE-4 DBE-4 DBE-4

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

CTC201A CTC209B CTC204A CTC212B CTC205B CTC215A

DBE-5 DBE-5 DBE-5 DBE-5 DBE-5 DBE-5

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-0.006

-0.004

-0.002

0.000

0.002

1 2 3 4 5 6

-0.010

-0.008

-0.006

-0.004

-0.002

0.000

0.002

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.000

0.004

0.008

0.012

0.016

0.020

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.000

0.004

0.008

0.012

0.016

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-0.04

-0.03

-0.02

-0.01

0.00

1 2 3 4 5 6

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.01

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.000

0.005

0.010

0.015

0.020

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-2.0

-1.6

-1.2

-0.8

-0.4

0.0

1 2 3 4 5 6

-4

-3

-2

-1

0

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

-3

-2

-1

0

1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
334

Figure C-65. Plots of experimental and calculated environmental chamber reactivity results for the 

Texanol®1isomers.

 

1 Texanol is a trademark of Eastman Chemical Company.

EPA229A EPA230B EPA231B EPA232A

TEXANOL TEXANOL TEXANOL TEXANOL

IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-7 LN2

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0.2

0 1 2 3 4 5 6

-400

-300

-200

-100

0

100

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0.2

0 1 2 3 4 5 6

-400

-300

-200

-100

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0 1 2 3 4 5 6

-160

-120

-80

-40

0

40

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0.2

0 1 2 3 4 5 6

-160

-120

-80

-40

0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc
335

Figure C-66. Plots of model errors in simulations of the furan - NOx environmental chamber 

experiments. 

Furan - NOx Experiments

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

EPA Chm., Arc 2 -29% 1% -28% -25%

EPA Chm, Black 2 -55% -26% 12% -26%

ITC Chamber 4 -20% 47% -15% 1%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

EPA Chm., Arc

EPA Chm, Black

ITC Chamber

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
336

Figure C-67. Plots of model errors in simulations of the methyl furan - NOx environmental chamber 

experiments. 

Methylfuran - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final

2-Methyl, Arc 2 (Not represented) -13% -12%

3-Methyl, Arc 4 -15% -23%

3-Methyl, Black 2 -3% -21%

2,5-Dimethyl, Arc 2 -19% -24%

SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

2-Methyl, Arc

3-Methyl, Arc

3-Methyl, Black

2,5-Dimethyl, Arc

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
337

Figure C-68. Plots of model errors in simulations of the benzyl alcohol and benzyl alcohol + CO - NOx

environmental chamber experiments. 

Benzyl Alcohol - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 3 7% 18% -1% 10%

Blacklight 2 -17% 11% 20% 7%

Added CO 1 -11% 3% -14% 19%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
338

Figure C-69. Plots of experimental and calculated environmental chamber reactivity results for benzyl 

alcohol.

EPA319A EPA323B EPA320B

BZ-CH2OH BZ-CH2OH BZ-CH2OH

IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 LN2

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-1.0

-0.5

0.0

0.5

1.0

0 1 2 3 4 5 6

-400

-200

0

200

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.5

0.0

0.5

1.0

1.5

0 1 2 3 4 5 6

-600

-400

-200

0

200

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3

-0.1

0.0

0.1

0.2

0.3

0 1 2 3

-160

-120

-80

-40

0

40

0 1 2 3

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc
339

Figure C-70. Plots of model errors in simulations of the formaldehyde - NOx environmental chamber 

experiments. 

Formaldehyde - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

UCR Arc Light 14 -3% -5% -8% -8%

UCR Blacklight 9 -6% -7% -7% -6%

TVA chamber 3 -1% -4% -3% -4%

Added CO 7 -10% -11% -6% -7%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

UCR Arc Light

UCR Blacklight

TVA chamber

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
340

Figure C-71. Plots of experimental and calculated environmental chamber reactivity results for 

formaldehyde.

ETC352 ETC357 ETC470 ETC489

FORMALD FORMALD FORMALD FORMALD

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-E MIR1 IR Surg-E MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

CTC138B CTC140A DTC022B DTC036A

FORMALD FORMALD FORMALD FORMALD

IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0

1

2

3

4

5

1 2 3 4 5 6

0

1

2

3

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-0.2

0.0

0.2

0.4

0.6

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0

50

100

150

200

1 2 3 4 5 6

0

40

80

120

160

1 2 3 4 5 6

0

5

10

15

20

25

1 2 3 4 5 6 -10

0

10

20

30

1 2 3 4 5 6 0

20

40

60

1 2 3 4 5 6

0

4

8

12

16

20

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0

1

2

3

4

1 2 3 4 5 6

0

1

2

3

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0

40

80

120

1 2 3 4 5 6 -40

0

40

80

120

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
341

Figure C-72. Plots of model errors in simulations of the acetaldehyde - NOx environmental chamber 

experiments. 

Acetaldehyde - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 8 17% 16% 5% 5%

Blacklight 5 8% 4% 2% -1%

OTC Chamber 4 -2% 1% -5% -1%

Added CO 1 6% -5% 6% -5%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

OTC Chamber

Added CO

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
342

Figure C-73. Plots of experimental and calculated environmental chamber reactivity results for 

acetaldehyde.

CTC107A ETC335 ETC338 DTC065A DTC066B

ACETALD ACETALD ACETALD ACETALD ACETALD

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0.30

1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

1 2 3 4 5 6

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 2 3 4 5 6

-0.08

-0.07

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0.00

1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0 1 2 3 4 5 6

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

1 2 3 4 5 6

-20.0

-15.0

-10.0

-5.0

0.0

5.0

1 2 3 4 5 6

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

2.0

4.0

1 2 3 4 5 6

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

1 2 3 4 5 6

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
343

Figure C-74. Plots of model errors in simulations of the acrolein and methacrolein (MA) - NOx

environmental chamber experiments.

Acrolein, Methacrolein - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Acrolein 3 -16% 0% -5% 2%

MA, XTC Chamber 2 -16% -11% -19% -13%

MA, EC Chamber 4 3% 30% -8% 18%

MA, Blacklights 6 17% -8% 1% -11%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Acrolein

MA, XTC Chamber

MA, EC Chamber

MA, Blacklights

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
344

Figure C-75. Plots of experimental and calculated environmental chamber reactivity results for 

benzaldehyde.

CTC267B CTC266A EPA380B

BENZALD BENZALD BENZALD

IR Surg-8 LN1 IR Surg-x MIR1 IR Surg-7 MIR2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-50

-40

-30

-20

-10

0

1 2 3 4 5 6

-120

-80

-40

0

40

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

0 1 2 3 4 5 6

-300

-200

-100

0

0 1 2 3 4 5 6
345

Figure C-76. Plots of model errors in simulations of the acetone - NOx environmental chamber 

experiments. 

Acetone - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Arc Light 2 -16% -16% -34% -31%

Blacklight 3 23% 27% -4% 6%

OTC Chamber 2 -13% -3% -29% -14%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Arc Light

Blacklight

OTC Chamber

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
346

Figure C-77. Plots of experimental and calculated environmental chamber reactivity results for 

acetone.

ETC243 ETC245 ETC247 DTC028A DTC064B

ACETONE ACETONE ACETONE ACETONE ACETONE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

OTC275A OTC276B ETC480 ETC481 ETC490

ACETONE ACETONE ACETONE ACETONE ACETONE

IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-E MIR1 IR Surg-E MIR1 IR Surg-E MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0.20

1 2 3 4 5 6

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.5

1.0

1.5

2.0

0 1 2 3 4 5 6

-4

0

4

8

12

1 2 3 4 5 6

-2

0

2

4

6

1 2 3 4 5 6 0

1

2

3

1 2 3 4 5 6 -0.2

0.0

0.2

0.4

0.6

0.8

1 2 3 4 5 6

-0.2

0.0

0.2

0.4

1 2 3 4 5 6

-0.8

-0.4

0.0

0.4

0.8

1.2

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

2.0

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

0.05

1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

0.05

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

-1.0

-0.5

0.0

0.5

1.0

1.5

1 2 3 4 5 6

-1

0

1

2

1 2 3 4 5 6

-0.5

0.0

0.5

1.0

1.5

2.0

1 2 3 4 5 6

-0.8

-0.4

0.0

0.4

0.8

1.2

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
347

Figure C-78. Plots of model errors in simulations of the methyl ethyl ketone (MEK), 2-pentanone 

(MPK) and 2-heptanone - NOx environmental chamber experiments. 

Ketone - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

MEK, Arc 2 -6% -6% -5% -7%

MEK, Black 4 6% 7% 8% 7%

MPK 1 13% 2% 6% -2%

2-Heptanone 1 9% -1% -43% -39%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

MEK, Arc

MEK, Black

MPK

2-Heptanone

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
348

Figure C-79. Plots of experimental and calculated environmental chamber reactivity results for methyl 

ethyl ketone.

CTC181A DTC363A CTC180B DTC338A DTC345B

MEK MEK MEK MEK MEK

IR Surg-3 MIR1 IR Surg-x MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-x MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

1 2 3 4 5 6 0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

0.05

1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-1.5

-1.0

-0.5

0.0

0.5

1.0

1 2 3 4 5 6

-2

-1

0

1

2

1 2 3 4 5 6

-2

-1

0

1

2

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
349

Figure C-80. Plots of experimental and calculated environmental chamber reactivity results for 2-

pentanone.

CTC255A CTC260B CTC263B CTC258B

MPK MPK MPK MPK

IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

0.04

1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.020

-0.015

-0.010

-0.005

0.000

0.005

1 2 3 4 5 6

-0.03

-0.02

-0.01

0.00

0.01

0.02

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-8

-6

-4

-2

0

2

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

-8

-6

-4

-2

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
350

Figure C-81. Plots of experimental and calculated environmental chamber reactivity results for 4-

methyl-2-pentanone and 2-heptanone.

CTC183A DTC366B DTC369A CTC182B DTC370B DTC414A

MIBK MIBK MIBK MIBK MIBK MIBK

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC412B DTC418A CTC257A CTC262A CTC259A

MIBK MIBK C7-KET-2 C7-KET-2 C7-KET-2

IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.20

-0.15

-0.10

-0.05

0.00

0.05

1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.08

-0.06

-0.04

-0.02

0.00

0.02

0.04

1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

-8

-6

-4

-2

0

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

-8

-6

-4

-2

0

1 2 3 4 5 6

-8

-6

-4

-2

0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.025

-0.020

-0.015

-0.010

-0.005

0.000

1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.16

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

-0.04

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-6

-4

-2

0

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-8

-6

-4

-2

0

2

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-8

-6

-4

-2

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
351

Figure C-82. Plots of experimental and calculated environmental chamber reactivity results for 

cyclohexanone.

CTC227A DTC554B DTC558A CTC229B DTC556A

CC6-KET CC6-KET CC6-KET CC6-KET CC6-KET

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC559B CTC235A CTC238A DTC557B

CC6-KET CC6-KET CC6-KET CC6-KET

IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

1 2 3 4 5 6

-0.20

-0.15

-0.10

-0.05

0.00

0.05

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-16

-12

-8

-4

0

4

1 2 3 4 5 6

-10

-8

-6

-4

-2

0

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-8

-6

-4

-2

0

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

0.04

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.05

-0.04

-0.03

-0.02

-0.01

0.00

0.01

1 2 3 4 5 6

-10

-8

-6

-4

-2

0

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-10

-8

-6

-4

-2

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
352

Figure C-83. Plots of model errors in simulations of the methyl vinyl ketone - NOx environmental 

chamber experiments. 

MVK - NOx Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

EC Chamber 3 -3% 17% -10% 11%

Blacklight 3 0% -6% -15% -11%

SAPRC-99 SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors (Fraction of runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

EC Chamber

Blacklight

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
353

Figure C-84. Plots of experimental and calculated ([O3]-[NO]), cresol, and PAN concentrations in the 

cresol - NOx environmental chamber experiments.

Figure C-85. Plots of experimental and calculated environmental chamber reactivity results for mcresol.

EC281

o-Cresol

EC289

m-Cresol

EC290

p-Cresol

([O3]-[NO]) (ppm)

Cresol (ppm)

PAN (ppm)

Irradiation time (minutes)

0.0

0.2

0.4

0.6

0 120 240 360

0.0

0.2

0.4

0.6

0 120 240 360

0.0

0.1

0.2

0.3

0.4

0.5

0 120 240 360

0.0

0.1

0.2

0.3

0.4

0.5

0 120 240 360

0.0

0.1

0.2

0.3

0.4

0 120 240 360

0.0

0.1

0.2

0.3

0.4

0 120 240 360

0.000

0.002

0.004

0.006

0.008

0 120 240 360

0.000

0.002

0.004

0.006

0.008

0 120 240 360

0.000

0.002

0.004

0.006

0.008

0 120 240 360

EPA383B M-CRESOL IR Surg-7 LN2

(O3-NO) (ppm) IR (O3-NO)

(mole basis) IR IntOH (ppt-min/ppm) m-Cresol (ppm)

0.00

0.05

0.10

0.15

0 1 2 3 4 5 6 -0.6

-0.4

-0.2

0.0

0.2

0.4

0 1 2 3 4 5 6

-200

-150

-100

-50

0

50

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc

0.00

0.02

0.04

0.06

0.08

0.10

0 1 2 3 4 5 6
354

Figure C-86. Plots of experimental and calculated environmental chamber reactivity results for para 

toluene isocyanate.

DTC601A DTC602A DTC618A DTC610A DTC604B DTC608A

P-TI P-TI P-TI P-TI P-TI P-TI

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

1 2 3 4 5 6 -0.04

-0.03

-0.02

-0.01

0.00

0.01

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.012

-0.008

-0.004

0.000

0.004

1 2 3 4 5 6

-0.02

-0.01

0.00

0.01

0.02

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.04

-0.03

-0.02

-0.01

0.00

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.020

-0.016

-0.012

-0.008

-0.004

0.000

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-4

0

4

8

12

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

-6

-4

-2

0

1 2 3 4 5 6

-3

-2

-1

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
355

Figure C-87. Plots of experimental and calculated environmental chamber reactivity results for 2,4-

toluene diisocyanate (TDI1) and 2,6-toluene diisocyanate (TDI2).

DTC447A DTC450A DTC456A DTC459A

TDI TDI TDI TDI

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC453A DTC454A DTC462B DTC467A DTC466A

TDI TDI TDI TDI2 TDI2

IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-3 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

1 2 3 4 5 6

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0.2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.16

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-8

-6

-4

-2

0

2

1 2 3 4 5 6

-20

-15

-10

-5

0

5

1 2 3 4 5 6

-20

-16

-12

-8

-4

0

1 2 3 4 5 6

-30

-20

-10

0

10

20

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

-25

-20

-15

-10

-5

0

1 2 3 4 5 6

-20

-15

-10

-5

0

5

1 2 3 4 5 6

-40

-30

-20

-10

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
356

Figure C-88. Plots of experimental and calculated environmental chamber reactivity results for nmethyl-2-pyrrolidone.

DTC240A DTC244B DTC252A DTC255B DTC261A DTC267B

NMP NMP NMP NMP NMP NMP

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

1 2 3 4 5 6

0.0

0.2

0.4

0.6

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.1

0.0

0.1

0.2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

-10

-8

-6

-4

-2

0

1 2 3 4 5 6

-30

-20

-10

0

10

1 2 3 4 5 6

-50

-40

-30

-20

-10

0

1 2 3 4 5 6

-30

-20

-10

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
357

Figure C-89. Plots of experimental and calculated environmental chamber reactivity results for npropyl bromide and n-butyl bromide.

DTC421A DTC433A DTC423B DTC427A DTC424A DTC428B

C3-BR C3-BR C3-BR C3-BR C3-BR C3-BR

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC401A DTC426B DTC419B DTC430A DTC420B DTC432B

C4-BR C4-BR C4-BR C4-BR C4-BR C4-BR

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

-0.04

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-0.02

-0.01

0.00

0.01

0.02

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-1

0

1

2

3

1 2 3 4 5 6

-4

-2

0

2

4

1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-8

-6

-4

-2

0

1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.02

-0.01

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.02

-0.01

0.00

0.01

0.02

0.03

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-2

-1

0

1

1 2 3 4 5 6

-3

-2

-1

0

1

1 2 3 4 5 6

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
358

Figure C-90. Plots of experimental and calculated environmental chamber reactivity results for 

trichloroethylene.

DTC303B DTC305A DTC308B DTC311B DTC320A

CL3-ETHE CL3-ETHE CL3-ETHE CL3-ETHE CL3-ETHE

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC309A DTC321B DTC312A

CL3-ETHE CL3-ETHE CL3-ETHE

IR Surg-8 LN1 IR Surg-8 LN1 IR Surg-X LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6 -0.04

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

0.08

0.12

1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.04

0.00

0.04

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-1.6

-1.2

-0.8

-0.4

0.0

0.4

1 2 3 4 5 6

-3

-2

-1

0

1

2

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-2

0

2

4

6

1 2 3 4 5 6

-4

0

4

8

12

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

0.08

1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-10

-8

-6

-4

-2

0

1 2 3 4 5 6

-4

0

4

8

12

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
359

Figure C-91. Plots of model errors in simulations of the 1,3-dichloropropene and 1,3-dichloropropene 

+ n-butane - NOx environmental chamber experiments. 

1,3-Dichloropropene Runs

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

13-DCP - NOx 4 0% 0% -18% -9%

DCP + n-C4 - NOx 2 0% 0% -24% -13%

SAPRC-07

Average Model Error vs Hour of Run

Group Runs

Distribution of Final Hour Model Errors (Fraction of 

runs vs error range)

Distribution of Hour 2 Model Errors (Fraction of 

runs vs error range)

-75%

-50%

-25%

0%

25%

50%

75%

1 2 3 4 5 6

13-DCP - NOx

DCP + n-C4 - NOx

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
360

Figure C-92. Plots of experimental and calculated environmental chamber reactivity results for the 1,3-

dichloropropenes.

Figure C-93. Plots of experimental and calculated environmental chamber reactivity results for 2-

(chloromethyl)-3-chloro-propene.

EPA550A EPA554B EPA555B

13-DCP 13-DCP 13-DCP

IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-8 vary

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0 1 2 3 4 5 6

-200.0

-150.0

-100.0

-50.0

0.0

50.0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.05

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 1 2 3 4 5 6

-80.0

-60.0

-40.0

-20.0

0.0

20.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 1 2 3 4 5 6

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 1 2 3 4 5 6

-150.0

-100.0

-50.0

0.0

50.0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc

ETC342 CL2IBUTE IR Surg-3 MIR1

(O3-NO) (ppm) vs Hour IR (O3-NO) (mole basis) 

vs Hour

IR IntOH (ppt-min/ppm) vs 

Hour

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 1 2 3 4 5 6

0.00

1.00

2.00

3.00

4.00

5.00

6.00

1 2 3 4 5 6 -50.0

0.0

50.0

100.0

150.0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
361

Figure C-94 Plots of model errors in simulations of the chloropicrin (CP) – alkane - NOx and the 

chlorine + alkane - NOx experiments. 

Chlorine and Chloropicrin

Average ([O3]-[NO]) Model Error

SAPRC-99 SAPRC-07

2-Hr Final 2-Hr Final

Cl2 + n-C4 - NOx 2 4% 5%

CP + n-C4 - NOx 2 14% 8%

CP + C2 + NOx 2 1% 2%

CP + n-C4 - Air 2 -1% -6%

SAPRC-07

Average Model Error vs Hour of Run

Distribution of Final Hour Model Errors

(Fraction of runs vs error range)

Distribution of Hour 2 Model Errors

(Fraction of runs vs error range)

Group Runs

-50%

-25%

0%

25%

50%

1 2 3 4 5 6

Cl2 + n-C4 - NOx

CP + n-C4 - NOx

CP + C2 + NOx

CP + n-C4 - Air

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%

0%

20%

40%

60%

80%

100%

<-80%

-80%--60%-60%--40%-40%--20%

-20%-0%

0%-20%

20%-40%40%-60%60%-80%

>-80%
362

Figure C-95. Plots of experimental and calculated environmental chamber reactivity results for 

chloropicrin.

(IntCl is integrated chlorine calculated from the consumption 

rate for n-octane relative to the consumption rate of m-xylene)

Figure C-96. Plots of experimental and calculated environmental chamber reactivity results for 

chlorine. Note that chlorine was added to the "base case" experiment after four hours of 

irradiation. 

CTC112A CTC119B CTC121A CTC124B CTC126A

CCL3NO2 CCL3NO2 CCL3NO2 CCL3NO2 CCL3NO2

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR2 IR Surg-8 MIR2

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

0

5

10

15

20

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.5

1.0

1.5

2.0

2.5

0 1 2 3 4 5 6

0

20

40

60

80

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4

0.0

0.5

1.0

1.5

2.0

0 1 2 3 4

0

20

40

60

80

0 1 2 3 4

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-20

-10

0

10

20

30

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0

10

20

30

40

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc

DTC323: Effect of Cl2 Additions

(O3

-NO)

(ppm)

(O3-NO) change / Cl2

added (mole basis)

n-Octane

(ppm) m-Xylene (ppm) IntOH change / Cl2

added (ppb-min/ppm)

IntCL

(ppt-min)

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6 -1

0

1

2

3

4

0 1 2 3 4 5 6

-200

-100

0

100

200

0 1 2 3 4 5 6

Side A (59 ppb Cl2 added at start) Side B (57 ppb Cl2 added at hour 4) Side A Calc Side B Calc

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6
363

Figure C-97. Plots of experimental and calculated environmental chamber reactivity results for 

hexamethyldisiloxane, d4 cyclosiloxane, and hydroxymethyldisiloxane.

ETC179 ETC391 ETC396 ETC398 ETC402 ETC406

SI2OME6 SI2OME6 SI2OME6 (SIOME)4 (SIOME)4 (SIOME)4

IR Surg-3 MIR1 IR Surg-X LN1 IR Surg-X LN1 IR Surg-X LN1 IR Surg-X LN1 IR Surg-X LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

ETC409 ETC412 ETC400 ETC404

SI2OMEOH SI2OMEOH SI2OMEOH SI2OMEOH

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-X LN1 IR Surg-X LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.16

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

-0.20

-0.16

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

1 2 3 4 5 6

-8

-6

-4

-2

0

2

1 2 3 4 5 6

-8

-6

-4

-2

0

2

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-16

-12

-8

-4

0

4

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.16

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

0.1

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-8

-6

-4

-2

0

2

1 2 3 4 5 6

-12

-8

-4

0

4

8

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-30

-20

-10

0

10

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
364

Figure C-98. Plots of experimental and calculated environmental chamber reactivity results for carbon

disulfide and methyl isothiocyanate.

EPA591A EPA592B EPA597B EPA598A

CS2 CS2 CS2 CS2

IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-7 LN2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

EPA587A EPA588B EPA589A EPA599A

MITC MITC MITC MITC

IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-7 LN2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

0.08

0 1 2 3 4 5 6

-20

-15

-10

-5

0

5

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2

0.00

0.01

0.02

0.03

0.04

0.05

0 1 2

-4

-2

0

2

4

0 1 2

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-0.01

0.00

0.01

0.02

0.03

0.04

0 1 2 3 4 5 6

-12

-8

-4

0

4

8

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-0.02

0.00

0.02

0.04

0.06

0.08

0 1 2 3 4 5 6

-15

-10

-5

0

5

10

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.05

0.00

0.05

0.10

0.15

0 1 2 3 4 5 6

-60

-40

-20

0

20

40

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

0.00

0.04

0.08

0 1 2 3 4 5 6

-20

-10

0

10

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

0.00

0.04

0.08

0 1 2 3 4 5 6

-8

-4

0

4

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0 1 2 3 4 5 6

-8

-4

0

4

8

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc
365

Figure C-99. Plots of experimental and calculated O3, NO, DMSO and formaldehyde in the dimethyl 

sulfoxide - NOx environmental chamber experiments.

Figure C-100. Plots of experimental and calculated environmental chamber reactivity results for 

dimethyl sulfoxide.

O3 NO DMSO Formaldehyde

DTC785B DTC785A

Time (minutes)

0.00

0.10

0.20

0.30

0.40

0.50

0 120 240 360

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0 120 240 360

0.00

0.05

0.10

0.15

0.20

0.25

0 120 240 360

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0 120 240 360

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0 120 240 360

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 120 240 360

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 120 240 360

0.00

0.05

0.10

0.15

0.20

0.25

0 120 240 360

Experimental SAPRC-07 SAPRC-99

DTC766A DTC783B DTC780B DTC786A DTC782A DTC787B

DMSO DMSO DMSO DMSO DMSO DMSO

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.4

0.8

1.2

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0

1

2

3

1 2 3 4 5 6

0.0

0.4

0.8

1.2

1.6

2.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-5

0

5

10

15

20

1 2 3 4 5 6

-10

0

10

20

30

1 2 3 4 5 6

-60

-40

-20

0

20

40

1 2 3 4 5 6

-10

-5

0

5

10

15

1 2 3 4 5 6

-80

-60

-40

-20

0

1 2 3 4 5 6

-120

-80

-40

0

40

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
366

Figure C-101. Plots of experimental and calculated environmental chamber reactivity results for s-ethyl 

dipropylthiocarbamate (EPTC).

EPA581A EPA586A EPA583B EPA584B EPA590B

EPTC EPTC EPTC EPTC EPTC

IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-7 LN2 IR Surg-7 LN2

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

0.1

0 1 2 3 4 5 6

-500

-400

-300

-200

-100

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5

-0.1

0.0

0.1

0 1 2 3 4 5

-400

-300

-200

-100

0

0 1 2 3 4 5

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0.4

0 1 2 3 4 5 6

-400

-300

-200

-100

0

100

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

0.1

0 1 2 3 4 5 6

-150

-100

-50

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.2

-0.1

0.0

0.1

0 1 2 3 4 5 6

-120

-80

-40

0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc
367

Figure C-102. Plots of experimental and calculated environmental chamber reactivity results for the 

mineral spirits samples studied for Safety-Kleen (Carter et al, 1997e).

DTC442A DTC486A DTC487B DTC441B DTC480A DTC481B

MS-A MS-A MS-A MS-B MS-B MS-B

IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC440A DTC478A DTC479B DTC439B DTC476A DTC477B

MS-C MS-C MS-C MS-D MS-D MS-D

IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

-0.02

-0.01

0.00

0.01

0.02

0.03

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.015

-0.010

-0.005

0.000

0.005

0.010

1 2 3 4 5 6

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.03

-0.02

-0.01

0.00

0.01

0.02

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.02

-0.01

0.00

0.01

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1

1 2 3 4 5 6

-4

-3

-2

-1

0

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

-0.03

-0.02

-0.01

0.00

0.01

0.02

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

-0.02

-0.01

0.00

0.01

0.02

1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.03

-0.02

-0.01

0.00

0.01

0.02

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.02

-0.01

0.00

0.01

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-6

-4

-2

0

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

-6

-4

-2

0

2

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

-5

-4

-3

-2

-1

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
368

Figure C-103. Plots of experimental and calculated environmental chamber reactivity results for Exxon 

Exxol® D95 Fluid and Exxon Isopar® M Fluid studied for ExxonMobil (Carter et al, 

2000e)1.

 

1 Exxol and Isopar are trademarks of ExxonMobil Chemical Company.

DTC753A DTC757A DTC754B DTC772B DTC756B DTC778A

D95 D95 D95 D95 D95 D95

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

DTC724B DTC720B DTC771A DTC723A DTC775B

ISOPARM ISOPARM ISOPARM ISOPARM ISOPARM

IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

1 2 3 4 5 6

-0.20

-0.16

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

1 2 3 4 5 6

-0.15

-0.10

-0.05

0.00

0.05

0.10

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

0.04

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

0.04

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-20

-16

-12

-8

-4

0

1 2 3 4 5 6

-20

-16

-12

-8

-4

0

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.4

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

0.04

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.15

-0.10

-0.05

0.00

0.05

0.10

1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

0.04

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-16

-12

-8

-4

0

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

-10

-8

-6

-4

-2

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
369

Figure C-104. Plots of experimental and calculated environmental chamber reactivity results for oxodecyl Acetate fluid studied for ExxonMobil (Carter et al, 2000e).

DTC760B DTC773A DTC769A DTC776A DTC770B

OC10ACET OC10ACET OC10ACET OC10ACET OC10ACET

IR Surg-3 MIR1 IR Surg-3 MIR1 IR Surg-8 MIR1 IR Surg-8 MIR1 IR Surg-8 LN1

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

1 2 3 4 5 6

-0.3

-0.2

-0.1

0.0

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0 1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

0.08

1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

0.08

1 2 3 4 5 6

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

1 2 3 4 5 6

0.0

0.1

0.2

0.3

0.4

0 1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

-12

-8

-4

0

4

1 2 3 4 5 6

-16

-12

-8

-4

0

4

1 2 3 4 5 6

-12

-8

-4

0

1 2 3 4 5 6

Base Experiment Test Experiment Base Model (SAPRC-07) SAPRC-07 Test Model SAPRC-99 Test Model
370

Figure C-105. Plots of experimental and calculated environmental chamber reactivity results for VMP 

Naphtha sample studied by Carter and Malkina (2005) and the Kerosene sample studied 

by Carter and Malkina (2007).

EPA137B EPA238A EPA126B EPA243B

VMPNAPH VMPNAPH VMPNAPH VMPNAPH

IR Surg-8 MIR2 IR Surg-7 MIR2 IR Surg-8 LN2 IR Surg-7 LN2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

EPA600B EPA607A EPA602A EPA603B

KEROSENE KEROSENE KEROSENE KEROSENE

IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-7 LN2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.04

-0.03

-0.02

-0.01

0.00

0 1 2 3 4 5 6

-40

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

0 1 2 3 4 5 6

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.04

-0.03

-0.02

-0.01

0.00

0 1 2 3 4 5 6

-20

-15

-10

-5

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.04

-0.03

-0.02

-0.01

0.00

0.01

0 1 2 3 4 5 6

-40

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-0.03

-0.02

-0.01

0.00

0.01

0 1 2 3 4 5 6

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6

-0.03

-0.02

-0.01

0.00

0.01

0 1 2 3 4 5 6

-25

-20

-15

-10

-5

0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-0.02

-0.01

0.00

0 1 2 3 4 5 6

-12

-8

-4

0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0 1 2 3 4 5 6

-25

-20

-15

-10

-5

0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc
371

Figure C-106. Plots of experimental and calculated environmental chamber reactivity results for the 

dearomatized alkanes mixed, predominately C10-C12 (ASTM-1C), synthetic isoparaffinic 

alkane mixture, predominately C10-C12 (ASTM-3C1), Reduced Aromatics Mineral Spirits 

(ASTM-1B), and Regular mineral spirits (ASTM-1A) solvents studied by Carter and 

Malkina (2005).

EPA168A EPA152B EPA163A EPA138B EPA150B EPA237B

ASTM-1C ASTM-1C ASTM-3C1 ASTM-3C1 ASTM-3C1 ASTM-3C1

IR Surg-8 MIR2 IR Surg-8 LN2 IR Surg-8 MIR2 IR Surg-8 LN2 IR Surg-8 LN2 IR Surg-7 LN2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

EPA151A EPA242B EPA139B EPA167B EPA153A EPA240A

ASTM-1B ASTM-1B ASTM-1B ASTM-1A ASTM-1A ASTM-1A

IR Surg-8 MIR2 IR Surg-7 LN2 IR Surg-8 vary IR Surg-8 MIR2 IR Surg-8 LN2 IR Surg-7 LN2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.16

-0.12

-0.08

-0.04

0.00

0 1 2 3 4 5 6

-60

-40

-20

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.05

-0.04

-0.03

-0.02

-0.01

0.00

0 1 2 3 4 5 6

-25

-20

-15

-10

-5

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.05

-0.04

-0.03

-0.02

-0.01

0.00

0 1 2 3 4 5 6

-50

-40

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.04

-0.02

0.00

0.02

0.04

0 1 2 3 4 5 6

-20

-15

-10

-5

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.06

-0.04

-0.02

0.00

0.02

0 1 2 3 4 5 6

-20

-15

-10

-5

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.04

-0.03

-0.02

-0.01

0.00

0.01

0 1 2 3 4 5 6

-16

-12

-8

-4

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.04

-0.03

-0.02

-0.01

0.00

0 1 2 3 4 5 6

-60

-40

-20

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.04

-0.03

-0.02

-0.01

0.00

0 1 2 3 4 5 6

-25

-20

-15

-10

-5

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.08

-0.06

-0.04

-0.02

0.00

0 1 2 3 4 5 6

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.02

-0.01

0.00

0.01

0.02

0.03

0 1 2 3 4 5 6

-40

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.04

-0.03

-0.02

-0.01

0.00

0.01

0 1 2 3 4 5 6

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.03

-0.02

-0.01

0.00

0 1 2 3 4 5 6

-20

-15

-10

-5

0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc
372

Figure C-107. Plots of experimental and calculated environmental chamber reactivity results for the 

aromatic-100 solvent studied by Carter and Malkina (2005).

Figure C-108. Plots of experimental and calculated environmental chamber reactivity results for 

ethanolamine and isopropyl amine. In order to obtain the fits shown, the initial amine 

concentrations had to be adjusted to optimize the model fits to the reactivity data.

EPA127A EPA244B EPA124A EPA239A

AROM100 AROM100 AROM100 AROM100

IR Surg-8 MIR2 IR Surg-7 MIR2 IR Surg-8 LN2 IR Surg-7 LN2

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.05

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-60

-40

-20

0

20

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.1

0.0

0.1

0.2

0.3

0 1 2 3 4 5 6

-60

-40

-20

0

20

40

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

0.08

0 1 2 3 4 5 6

-30

-20

-10

0

10

0 1 2 3 4 5 6

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

0.08

0 1 2 3 4 5 6

-30

-20

-10

0

10

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc

EPA780A EPA790A EPA791A EPA798A EPA805A EPA807A

ETOH-NH2 ETOH-NH2 ETOH-NH2 ETOH-NH2 ETOH-NH2 IPR-AMIN

IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 LN2 IR Surg-7 LN2 IR Surg-7 LN2 IR Surg-7 LN2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.04

0.08

0.12

0 1 2 3 4

-0.2

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4

-20

0

20

40

0 1 2 3 4

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6

-0.08

-0.04

0.00

0.04

0.08

0 1 2 3 4 5 6

-40

-20

0

20

40

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0 1 2 3 4 5 6

-200

-150

-100

-50

0

50

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6

-0.14

-0.07

0.00

0.07

0.14

0 1 2 3 4 5 6

-60

-40

-20

0

20

40

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6

-0.10

-0.05

0.00

0.05

0.10

0 1 2 3 4 5 6

-60

-40

-20

0

20

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0 1 2 3 4 5 6

-0.05

0.00

0.05

0.10

0.15

0.20

0 1 2 3 4 5 6

-60

-40

-20

0

20

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) Adj. Amine Test Calc
373

Figure C-109. Plots of experimental and calculated environmental chamber reactivity results for t-butyl 

amine and 2-amino-2-methyl-1-propanol. In order to obtain the fits shown, the initial 

amine concentrations had to be adjusted to optimize the model fits to the reactivity data.

EPA806A EPA781A EPA782A EPA799A

TBU-AMIN AMP AMP AMP

IR Surg-7 LN2 IR Surg-7 MIR2 IR Surg-7 MIR2 IR Surg-7 MIR2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

EPA783A EPA784A EPA789B EPA792A

AMP AMP AMP AMP

IR Surg-7 LN2 IR Surg-7 LN2 IR Surg-7 LN2 IR Surg-7 LN2

(O3-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.02

0.04

0.06

0.08

0 1 2 3 4 5 6

-0.12

-0.08

-0.04

0.00

0.04

0 1 2 3 4 5 6

-50

-40

-30

-20

-10

0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0 1 2 3 4 5 6

-0.15

-0.10

-0.05

0.00

0.05

0 1 2 3 4 5 6

-60

-40

-20

0

20

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0 1 2 3 4 5 6

-0.8

-0.4

0.0

0.4

0 1 2 3 4 5 6

-500

-400

-300

-200

-100

0

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-0.6

-0.4

-0.2

0.0

0 1 2 3 4 5 6

-150

-100

-50

0

50

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-0.8

-0.4

0.0

0.4

0 1 2 3 4 5 6

-200

-150

-100

-50

0

50

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-1.2

-0.8

-0.4

0.0

0.4

0 1 2 3 4 5 6

-400

-300

-200

-100

0

100

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0 1 2 3 4 5 6

-1.0

-0.5

0.0

0.5

0 1 2 3 4 5 6

-300

-200

-100

0

100

0 1 2 3 4 5 6

0.00

0.04

0.08

0.12

0.16

0 1 2 3 4 5 6

-0.4

-0.2

0.0

0.2

0 1 2 3 4 5 6

-100

-80

-60

-40

-20

0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) Adj. Amine Test Calc

Base Experiment Test Experiment Base Calc (SAPRC-07) Adj. Amine Test Calc
374

Figure C-110. Plots of selected experimental and calculated concentration-time plots for the methyl 

iodide - NOx, methyl iodide - CO - NOx, and methyl iodide - O3 experiments. 

EPA738A EPA743A EPA742B EPA742A

CH3I-NOx CH3I-NOx O3-CO O3-CO-CH3I

EPA734A EPA734B EPA738B EPA743B

CH3I-NOx+CO CH3I-NOx+CO CH3I-NOx+CO CH3I-NOx+CO

Time (minutes)

Concentration (ppm)

D(O3-NO)

0.000

0.005

0.010

0.015

0.020

0.025

0 120 240 360

D(O3-NO)

0.00

0.01

0.02

0.03

0 120 240 360

D(O3-NO)

0.00

0.04

0.08

0.12

0.16

0 120 240 360

O3

0.05

0.06

0.07

0.08

0.09

0.10

0 120 240 360

CH3I

0.188

0.192

0.196

0.200

0.204

0 120 240 360

CH3I

0.47

0.48

0.49

0.50

0.51

0 120 240 360

CH3I

0.184

0.188

0.192

0.196

0.200

0.204

0 120 240 360

D(O3-NO)

0.00

0.04

0.08

0.12

0.16

0 120 240 360

D(O3-NO)

0.00

0.04

0.08

0.12

0.16

0 120 240 360

O3

0.088

0.092

0.096

0.100

0.104

0 120 240 360

CH3I

0.184

0.188

0.192

0.196

0.200

0.204

0 120 240 360

CH3I

0.18

0.19

0.20

0.21

0 120 240 360

CH3I

0.44

0.45

0.46

0.47

0.48

0.49

0.50

0.51

0 120 240 360

CH3I

0.30

0.31

0.32

0.33

0.34

0.35

0 120 240 360

D(O3-NO)

0.00

0.01

0.02

0.03

0.04

0 120 240 360

Experimental Model
375

Figure C-111. Plots of experimental and calculated environmental chamber reactivity results for the 

methyl iodide experiments of Carter (2007).

EPA735B EPA736B EPA737A

CH3I CH3I CH3I

0.2011 0.3975 0.2129

(O3

-NO) (ppm) vs Hour

IR (O3-NO) (mole basis) vs Hour

IR IntOH (ppt-min/ppm) vs Hour

0.00

0.02

0.04

0.06

0.08

0.10

0 1 2 3 4 5 6

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20

0.25

0 1 2 3 4 5 6

-50.0

0.0

50.0

100.0

150.0

200.0

250.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0 1 2 3 4 5 6

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0 1 2 3 4 5 6

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

0 1 2 3 4 5 6

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0 1 2 3 4 5 6

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0 1 2 3 4 5 6

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

10.0

20.0

0 1 2 3 4 5 6

Base Experiment Test Experiment Base Calc (SAPRC-07) SAPRC-07 Test Calc SAPRC-99 Test Calc
376

APPENDIX D. SUPPLEMENTARY MATERIAL AVAILABLE

Complete documentation of this mechanism and its evaluation requires several tables that are too 

extensive to be appropriate for a printed report. These include the following:

Table A-3 Absorption cross-sections and quantum yields for all photolysis reactions in the base 

mechanism.

Table B-2 Listing of mechanisms for all VOCs for which mechanism assignments have been 

derived.

Table B-3 Listing of adjustable product mechanisms for all VOCs for which such mechanisms have 

been derived.

Table B-10 Listing of components of complex mixtures for which atmospheric reactivities have been 

calculated.

Table B-11 Assignments of explicitly represented compounds to lumped model species in the fixed 

parameter mechanism.

Table C-1 List of environmental chamber experiments used in the mechanism evaluation.

These are available in Excel files that can be downloaded using links at the SAPRC mechanism web site 

at http://www.cert.ucr.edu/~carter/SAPRC. These consist of saprc07.xls, that contains all the tables in 

Appendix A through Appendix C, and Table-A1.xls, Table-B2.xls, through Table-C1.xls that contain 

only the tables indicated. Because these files contain documentation information not included in the 

printable version of this report, these files must be considered to be an integral part of the SAPRC-07 

mechanism documentation.

The SAPRC mechanism web site at http://www.cert.ucr.edu/~carter/SAPRC is currently under 

development. At present it contains this report document (as a Microsoft Word and a PDF file), the files 

containing the supplementary material as discussed above, and the files to implement the mechanism and 

conduct the simulations of the chamber experiments and other test calculations. Additional files will be 

added as time permits if requested. The web site will contain documentation concerning the format and 

use of the available files.
377

APPENDIX E. CHANGE LOG

In this Appendix, the changes to the mechanism and the mechanism documentation that was 

distributed or made available at the SAPRC mechanism web site are listed. If the mechanism needs to be 

changed or corrected in the future, this report and the supplementary material will be changed 

accordingly, and the modifications will be listed in this section.

6/15/07 This is the version documented in the final report that was submitted as the deliverable for 

CARB Contract 03-318.

12/31/07 This revised version was prepared as part of work on CARB project 06-408. The 

modifications are as follows:

 The mechanisms for the amines were revised or added as a result of CARB project 06-408. 

This resulted in substantial changes in the reactivities for these compounds.

 Results of modeling chamber experiments carried out for CARB project 06-408 was added 

to the "Mechanism Evaluation Results" section. These were primarily amine experiments 

but included a few other compounds.

 A minor error in the representation of the peroxy + HO2 reactions was corrected.

 The reactivity scales were re-calculated after these changes were made. The effects of the 

changes were insignificant except for the amines..

5/21/08 This revised version was prepared as part of work on documenting the condensed version of 

SAPRC-07 and incorporates corrections of errors or omissions found during the course of the 

preparation of the condensed mechanism and other work. The reactivity scales were 

recalculated after these errors were corrected but the changes in the simulations of the 

chamber experiments were judged to be too small to revise the presentation of the fits of the 

model simulations to the chamber data. The modifications to the mechanism and the report 

were as follows:

 This Appendix E, giving the change log, was added to the report.

 An error in the rate constant for OH with 1,1-dichloroethene was corrected. This resulted in 

a decrease in the MIR of this compound from 2.76 to 1.69.

 The reactions of amines with O3 were added. This resulted in changes in MIR's for in 

certain amines of up to ~30%.

 The photolysis reactions for PAN2 and the other high PAN analogues were added, based 

on analogy with the photolysis of PAN that was already in the mechanism. This shouldn't 

significantly affect environmental chamber and atmospheric reactivity simulations in this 

report but may non-negligibly affect regional airshed model predictions under some 

conditions.

 The derivation of the lumped model species whose parameters depend on the base ROG 

mixture (e.g., ALKn, OLEn, AROn) were re-derived because the original values of the 

mole fractions of the components used as the weighting factors could not be exactly 

reproduced. This was necessary to derive a standardized spreadsheet to derive weighting

factors based on this mixture for mechanisms with other lumping schemes. The changes 

were small and only affect the fixed parameter version of the mechanism, but may have up 

to ~10% effects on MIR's for compounds whose reactivities are highly sensitive to the base 

mechanism.
378

 The OLE2 + Cl mechanism was revised to incorporate explicitly generated mechanisms for 

reactions of chlorine with 1,3-butadiene and 2-methyl-1-butene. This would not affect the 

reactivity results for these compounds.

 Minor errors in the zRNO3 yields in the AFGn reactions were corrected. These shouldn't 

significantly affect model results.

 A minor error in the rate constant for the NRAD + HO2 rate constant was corrected. This

shouldn't significantly affect model results.

 The files implementing the mechanism did not specify yRAOOH as a steady state species 

as documented, and this was corrected. This shouldn't affect model simulation results but 

might have a small effect on computer time, depending on how the mechanism is 

implemented.

 The reactivity scales were recalculated after these changes were made. Except for 1,1-

dichloroethene and amines discussed above the changes were relatively minor. The MIR 

for TDI, changed by about 12% and the MIRs for certain higher alkanes changed by as 

much as 8% but usually less than 5%. For most compounds the change in MIRs were less 

than 2%.

6/3/08 The CARB hydrocarbon bin reactivities (Kwok et al, 2000; Carter and Malkina, 2005) have 

been added to the reactivity tabulation in Table B-1 and the compositions used to calculate 

the reactivities of these bins have been added to Table B-10 (Table B-10 available with the 

supplementary materials only). A footnote was added to Table B-1 referencing the relevant 

hydrocarbon bin work. No change was made to the main body of the report text.

6/19/08 Minor editorial corrections made to the documentation in several places, and some updates 

made to the references.

7/7/08 An error in the spreadsheet used to derive the aromatics mechanism was found that affected 

computation of ratio of BALD and PROD2 yields used to represent aromatic aldehydes and 

ketones formed from abstractions on alkyl groups on alkylbenzenes. This affected the BALD 

and PROD2 yields in ARO2 and in alkylbenzenes with groups other than methyl, but had 

relatively small effects on reactivity and other calculation results. In addition, several xPROD 

species (xHNO3, xHCOOH, xCCOOH, xRCOOH) were found not to be needed in the 

lumped atmospheric mechanism and were deleted. For reactivity calculations, these are 

replaced by their corresponding product species. Because of the relatively low reactivity of 

these species, the effects of this approximation on reactivity calculations, especially for MIR 

conditions, should be negligible. The mechanism listings were updated and the reactivity 

scales on Table B-1 were recomputed using the current version of the mechanism.

3/13/09 Several corrections and revisions were made as a result of problems discovered during the 

peer review of the mechanism. These are as follows:

 An error in the activation energy for the HO2 + O3 reaction was corrected. This resulted in 

20% increase in this rate constant at 300oK.

 The reaction of formaldehyde with HO2 was deleted from the mechanism because as 

formulated in the mechanism it should be negligible under all relevant atmospheric and 

environmental chamber conditions. This permitted removal of one intermediate species 

from the mechanism.

 The rate constant expression for the reaction of OH radicals with methyl hydroperoxide 

was changed to that recommended by the NASA (2006) evaluation. This gives a 300oK 

rate constant that is 35% higher than that previously used, which was from the IUPAC 

(2006) evaluation. The IUPAC recommendation has since been changed to an expression 

that gives an even higher rate constant than the current NASA (2006) recommendation. 
379

The branching ratios for the two competing reactions were also changed slightly to be 

consistent with the NASA (2006) recommendation.

 The group additivity parameters used in the mechanism generation system to estimate rate 

constants for reactions of OH radicals with organic hydroperoxides were modified to be 

consistent with the revised rate constant and branching ratio used for OH + methyl 

hydroperoxide. The methyl hydroperoxide data indicate an unusually large group additivity 

correction for OOH substitution on alkyl groups, and also indicates a much higher rate 

constant for reaction at the OOH group in organic hydroperoxides than for H2O2. The 

parameters used in the previous version of the mechanism were in error and were not 

consistent even with the previously used IUPAC (2006) rate constant for OH + methyl 

hydroperoxide. The revised group additivity parameters resulted in changes in the rate 

constants and the product distributions derived for the reactions of OH with the lumped 

higher hydroperoxide species ROOH, R6OOH and RAOOH. The products of the CL + 

RAOOH reaction were also revised, since they were estimated based on those for the OH 

reaction.

 Composition assignments were revised for several mixtures for consistency with the 

speciation database, resulting in slight changes in reactivities calculated for these mixtures. 

The affected mixtures, listed in order of reactivity changes, were "isomers of 

ethylbenzene", "C10 alkenes", and "isomers of butyl benzene", and Table B-9 has been 

modified accordingly. The MIR changes caused by these reassignments these were 20%, 

9%, and 3%, respectively.

The plots and tables in this report giving model performance results in simulating these data 

have been updated using the current revised mechanism. However, these changes had minor 

or insignificant effect on model simulations of most of the chamber experiments, and did not 

require any revisions of parameters adjusted to fit the chamber data. 

The atmospheric reactivities summarized have been recalculated using the current version of 

the mechanism and the reactivity tabulations in Table B-1 and the Supplementary Materials 

have been updated accordingly. These changes did not have significant affects on any

calculated MIR values (changes being less than 4% for all compounds), but did cause 

changes of up to 25-30% for a few compounds in the lower NOx scenarios. This is consistent 

with the fact that the HO2 + O3 and the hydroperoxide reactions become more important 

under low NOx conditions.

6/8/09 Several fluoropropenes were added to the list of compounds with mechanisms and reactivity 

estimates based on the results of Carter (2009a,b), and a few minor corrections and additions 

were made to some of the footnotes in Table B-4.

6/10/09 Table 22 modified to include the values of all the chamber characterization parameters, not 

just RN-I.

6/22/09 The hydrocarbon bin reactivities and uncertainty classifications on Table B-1 were updated as 

discussed by Carter (2009c), which was added to the reference list. Some higher unspeciated 

aromatics compositions and reactivities on Table B-1 were also modified. Table B-10 in the 

electronic version was updated to give the revised bin and unspeciated aromatic 

compositions.

1/15/10 Several corrections and revisions were incorporated as a result of problems found with the 

mechanism or its documentation to date. These are summarized below.

 An error in the mechanism of the acyl peroxy + methyl peroxy reaction (Reaction BR24 in 

Table A-2) was corrected. The previous version had the alkoxy radical products forming in 

10% yields when they should have been 90%. This correction required changing the 
380

mechanisms for all the peroxy + acyl peroxy reactions to be consistent with this. This 

correction affected the predictions of some low NOx products but had insignificant effects 

on ozone predictions. Nevertheless, all the reactivity scales were recalculated.

 Several other errors in various peroxy + peroxy reactions were corrected. These had no 

significant effect on ozone and had only minor effects for some species under low NOx

conditions. 

 Errors in the calculations of the atmospheric reactivities of the tertiary amines were 

corrected. The previous atmospheric reactivity calculations did not take into account the 

NOx loss involved in their mechanisms, though the radical loss was taken into account. 

This resulted in the MIRs for these compounds becoming positive rather than negative, but 

low NOx reactivities becoming more negative. This only affects 2-amino-2-methyl-1-

propanol, t-butyl amine, and 2-amino-2-ethyl-1,3-propanediol. This did not affect the 

simulations of environmental chamber experiments with these compounds.

 Numerous errors in Table 1 were corrected. 

 A number of VOCs were added to the reactivity tabulation in previous revisions but 

information about their mechanisms was not included in the tables in Appendix B. This 

information has now been added.

 The methods for reactivity values for mixtures was revised to be derived from those given 

for their components, rather than calculated for each mixture directly, since this approach 

does not involve the lumping of compounds that can occur when directly computing 

reactivities of complex mixtures.

 The mechanism and reactivity values for 3-methoxy-3-methyl-1-butanol were updated 

based on recent data from our laboratory (Carter et al, 2010).

 Several minor errors or omissions found in various tables or the text were corrected.

1/27/10 An error in the files implementing the mechanism, resulting in the rate constant for the 

O

1D+H2O reaction being low by ~18%, was corrected, and all calculations were redone. This 

had no significant effects on the simulations of the chamber experiments used in the 

mechanism evaluations, but had small but nonnegligible effects (on the order of ~10%) on 

ambient simulations and atmospheric reactivity values. Affected tables and plots, including 

Table B-1 giving the reactivity vales, werer updated.