1

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

California Environmental Protection Agency 

AIR RESOURCES BOARD 

CALIFORNIA NON-METHANE ORGANIC GAS 

TEST PROCEDURES

Adopted: July 12, 1991 

Amended: September 22, 1993 

Amended: June 24, 1996 

Amended: August 5, 1999 

Amended: July 30, 2002 

 Amended: March 22, 2012 

Amended: December 6, 2012 

Monitoring and Laboratory Division, Southern Laboratory Branch 

Mobile Source Division 

9528 Telstar Avenue 

El Monte, California 91731 

NOTE: Mention of any trade name or commercial product does not constitute endorsement or 

recommendation of this product by the Air Resources Board. Note: The proposed 

amendments to this document are shown in underline to indicate additions and strikeout to 

indicate deletions compared to the test procedures as last amended March 22, 2012. [No 

change] indicates proposed federal provisions that are also proposed for incorporation 

herein without change. Existing intervening text that is not amended in this rulemaking is 

indicated by “* * * *”. 

 
2

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

* * * * 

 PART B 

DETERMINATION OF NON-METHANE HYDROCARBON MASS EMISSIONS 

BY FLAME IONIZATION DETECTION 

* * * * 

 5. NMHC MASS EMISSION PER TEST PHASE

* * * * 

 5.2 All Vehicles

* * * * 

5.2.5 The density of the NMHC is determined using the carbon:hydrogen ratio of the fuel, 

CxHyOz, according to the following equation: 

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24.055 liter/mole

28.316847 liter/ft3 NMHCdens (x 12.01115 y *1.00797)(g / mole) *

where: 12.01115 = atomic weight of carbon 

 1.00797 = atomic weight of hydrogen 

 

except when using any gasoline-based fuel, including Phase 2 gasoline and E85 fuel, for which the 

NMHCdens is defined as 16.33. 

* * * * 

 7. SAMPLE CALCULATIONS

7.1 Given the following data for a gasoline vehicle operated on phase 2 certification fuel, 

CH1.964O0.0182, calculate the weighted NMHC mass emission. 
3

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

Test 

Phase 

FID THCe

(ppmC) 

FID THCd

(ppmC) 

CH4e

(ppmC) 

CH4d

(ppmC) 

COem

(ppm) 

CO2e

(%) 

VMIX 

(ft3) 

Dphase n

(mile) 

1 21.928 3.557 3.667 2.545 94.758 0.9581 2745 3.610 

2 3.826 3.533 2.694 2.490 16.516 0.5925 4700 3.876 

3 4.242 3.386 2.769 2.414 11.524 0.8225 2738 3.611 

For Phase 1: 

NMHCe = FID THCe - (rCH4

 * CH4e ) 

 = 21.928 ppmC - (1.15 * 3.667 ppmC) 

 = 17.711 ppmC 

 NMHCd = FID THCd - (rCH4

 * CH4d ) 

 = 3.557 ppmC - (1.15 * 2.545 ppmC) 

 = 0.630 ppmC 

 The numerator of the DF 

 = 100 * ( x / ( x + y/2 + 3.76 * ( x + y/4 – z/2) ) 

 = 100 * ( 1 / 1 + 1.964 / 2 + 3.76 * ( 1 + 1.964 / 4 – 0.0182 / 2) 

 = 13.2381 

 DF = 13.2381 ÷ [CO2e + (NMHCe + CH4e + COe ) * 10-4] 

 DF =   4 0.9581 17.711ppmC 3.667 ppmC 94.758 ppmC 10

13.2381      

 

 = 13.653 

 NMHCconc = NMHCe - NMHCd * [1 - (1 ÷ DF)] 

 = 17.711 ppmC – 0.630 ppmC * [1 - (1 ÷ 13.653)] 

 = 17.127 ppmC 

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24.0547liter/mole

28.316847liter/ft3 NMHCdens (x 12.01115 y *1.00797)(g / mole) *

 

 NMHCdens = 16.33 g/ft3

 (1 * 12.01115 + 1.964 *1.00797 )* (28.316847/24.055) 

 = 16.470 g/ft3

 NMHCmass n = NMHCconc * NMHCdens * VMIX * 10-6

 = 17.127 ppmC * 16.3347 g/ft3

 * 2745 ft3 * 10-6
4

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

 NMHCmass 1 = 0.77043 g 

 Similarly, for Phase 2: NMHCmass 2 = 0.0068 g 

 and for Phase 3: NMHCmass 3 = 0.02179 g 

 Therefore, 

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phase3 phase2

mass3 mass2

phase1 phase2

mass1 mass2

wm D D

NMHC NMHC 0.57

D D

NMHC NMHC NMHC 0.43

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3.611 miles 3.876 miles

0.0217g 0.0068g 0.57

3.610 miles 3.876 miles

0.768g 0.0068g NMHC 0.43 wm

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3.611 miles 3.876 miles

0.0217g 0.0068g 0.57

3.610 miles 3.876 miles

0.770 g 0.0068 g NMHC 0.43 wm

 NMHCwm = 0.047 g/mile 

7.2 Given the following data for a vehicle operating on 10% ethanol and 90% gasoline (E10) 

CH1.87842.7841O0.03380.3835, calculate the weighted NMHC mass emission. 

Test 

Phase 

FID 

THCe

(ppmC) 

FID 

THCd

(ppmC) 

CH4e

(ppmC) 

CH4d 

(ppmC) 

COem

(ppm) 

CO2e

(%) 

VMIX 

(ft3) 

Dphase n

(mile) 

1 14.398 2.971 3.639 2.125 97.83 0.9203 3508 3.590 

2 2.882 2.830 2.176 2.010 12.25 0.5935 6010 3.858 

3 3.976 2.642 2.621 2.058 19.86 0.7624 3502 3.581 

 For Phase 1: 

 NMHCe = FID THCe - (rCH4

 * CH4e) 

 = 14.398 ppmC - (1.15 * 2.215 ppmC) 

 = 10.213 ppmC 

 NMHCd = FID THCd - (rCH4

 * CH4d) 

 = 2.971 ppmC - (1.15 * 2.125 ppmC) 

 = 0.527 ppmC 

 The numerator of the DF 

 = 100 * ( x / ( x + y/2 + 3.76 * ( x + y/4 – z/2))) 

 = 100 * ( 1 / (1 + 1.8784 / 2 + 3.76 * ( 1 + 1.8784 / 4 – 0.0338 / 2))) 

 = 13.511 
5

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

 DF = 13.511 ÷ [CO2e + (NMHCe + CH4e + COe) * 10-4] 

  4 0.9203 10.213ppmC 3.639 ppmC 97.83ppmC 10

13.511      

 = 14.505 

 NMHCconc = NMHCe - NMHCd * [1 - (1 / DF)] 

 = 10.213 ppmC – 0.527 ppmC * [1 - (1 / 14.505)] 

 = 9.722 ppmC 

 NMHCmass n = NMHCconc * NMHCdens * VMIX * 10-6

 

 NMHCmass 1 = 0.5578 g 

 Similarly, Phase 2: NMHCmass 2 = 0.0 g 

 and for Phase 3: NMHCmass 3 = 0.040 g 

 Therefore, 

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phase3 phase2

mass3 mass2

phase1 phase2

mass1 mass2

wm D D

NMHC NMHC 0.57

D D

NMHC NMHC NMHC 0.43

 

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3.581 miles 3.858 miles

0.040g 0.00g 0.57

3.590 miles 3.858 miles

0.558g 0.00g NMHC 0.43 wm

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3.581 miles 3.858 miles

0.040g 0.00g 0.57

3.590 miles 3.858 miles

0.557g 0.00g NMHC 0.43 wm

 NMHCwm = 0.035 g/mile 

* * * * 

 
6

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

Part D 

DETERMINATION OF C2 TO C5 HYDROCARBONS 

IN AUTOMOTIVE SOURCE SAMPLES BY GAS CHROMATOGRAPHY 

METHOD NO. 1002

* * * * 

 2. METHOD SUMMARY

* * * * 

 2.2 The samples are received by the laboratory in Tedlar®, Kynar®, or Solef® bags, 

which are sub-sampled into a GC for separation and analysis. 

* * * * 

 4. INSTRUMENTS AND APPARATUS

4.1 Kynar® (polyvinylidene fluoride) Sample collection bags, 4 mil in thickness, 

nominally 5 to 10 liters in capacity and equipped with quick-connect fittings, are 

typically used to contain the samples. Sample collection bags may be made of 

Tedlar® (polyvinylfloride, or PVF), 2 mil in thickness, or of Kynar® or Solef®

(polyvinylidenefloride, or PVDF), each 4 mil in thickness. Other sample bag 

material or sample collection containers, such as bags made of Tedlar® 

(polyvinyl fluoride) film or nickel-coated stainless steel canisters, may be used, 

provided they are made of non-reactive material and do not cause sample loss or 

contamination. 

* * * * 

 
7

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

Part E 

DETERMINATION OF C6 TO C12 HYDROCARBONS 

IN AUTOMOTIVE SOURCE SAMPLES BY GAS CHROMATOGRAPHY 

METHOD NO. 1003 

* * * * 

 2. METHOD SUMMARY

* * * * 

 2.2 The samples are received by the laboratory in Tedlar®, Kynar®, or Solef® bags, 

which are sub-sampled into a GC for separation and analysis. 

* * * * 

 4. INSTRUMENTATION AND APPARATUS 

4.1 Kynar® (polyvinylidene fluoride) Sample collection bags, 4 mil in thickness, 

nominally 5 to 10 liters in capacity and equipped with quick-connect fittings, are 

typically used to contain the samples. Sample collection bags may be made of 

Tedlar® (polyvinylfloride, or PVF), 2 mil in thickness, or of Kynar® or Solef®

(polyvinylidenefloride, or PVDF), each 4 mil in thickness. Other sample bag 

material or sample collection containers, such as bags made of Tedlar® 

(polyvinyl fluoride) film or nickel-coated stainless steel canisters, may be used, 

provided they are made of non-reactive material and do not cause sample loss or 

contamination. 

* * * * 

 
8

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

Part F 

DETERMINATION OF ALDEHYDE AND KETONE COMPOUNDS 

IN AUTOMOTIVE SOURCE SAMPLES 

BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY 

METHOD NO. 1004

* * * * 

 7. CALCULATIONS

* * * * 

7.3 For tolualdehyde, the sum of all isomers present is reported as m-tolualdehyde. 

 

 Under the conditions of the system described in Section 6.6, the isomers coelute. 

The m-tolualdehyde response factor is applied to the single tolualdehyde peak. 

This concentration is reported as m-tolualdehyde. 

* * * * 
9

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

Part G 

DETERMINATION OF NMOG MASS EMISSIONS

* * * * 

 3. DILUTION FACTOR AND NMHC MASS EMISSION CALCULATION

* * * * 

 3.2 The density of the NMHC is determined using the carbon:hydrogen ratio of 

the fuel, CxHyOz, according to the following equation: 



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 



   

24.0547liter/mole

28.316847liter/ft3 NMHCdens (x 12.01115 y *1.00797)(g / mole) *

where: 12.01115 = atomic weight of carbon 

 1.00797 = atomic weight of hydrogen 

except when using any gasoline-based fuel, including Phase 2 gasoline and 

E85 fuel, for which the NMHCdens is defined as 16.33. 

* * * * 

 b) For Phase 2 gasoline, CH1.94O0.017, where x = 1, y = 1.94 and z = 0.017, 

 DF = 13.295 / [CO2e + (NMHCe + CH4e + COe) * 10-4] 

 NMHCdens = 16.33 16.44 

* * * * 

 e) For E85, CH2.7841O0.3835, Wwhere x = 1, y = 2.7841, and z = 0.3835: 

 DF = 12.4253 / [CO2e + (NMHCe + CH4e + COe) * 10-4] 

NMHCdens = 16.33 17.44 

3.3 Sample Calculation 

 A flex-fuel vehicle using E85 fuel CH2.7841O0.3835, where x = 1, y = 2.7841, 

and z = 0.3835: 

Test 

Phase 

FID 

THCe

(ppmC) 

CH4e

(ppmC) 

CO2e

(%) 

COe

(ppm) 

FID 

THCd

(ppmC) 

CH4d

(ppmC) 

CO2d

(%) 

COd

(ppm) 

VMIX 

(ft3

) 

Dphase n

(mile) 

1 27.230 6.918 0.8564 117.801 3.532 2.261 0.0438 0.5224 3495 3.591 

2 3.5459 2.357 0.5595 10.8229 3.476 2.247 0.4446 0.3322 5799 3.846 

3 3.8510 2.590 0.7163 5.1538 3.396 2.188 0.4507 0.6752 3484 3.591 
10

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

FID response factor of methane is experimentally determined for each individual FID. 

The value of 1.15 used here is for example only. 

For phase 1: 

NMHCe = FID THCe – r CH4

 * CH4e 

 = 27.230 – 1.15 * 6.918 

 = 19.274 ppmC 

DF = 12.4253 / [CO2e + (NMHCe + CH4e + COe) * 10-4] 

 = 12.4253 / [0.8564 + (19.274 + 6.918 + 117.801) * 10-4] 

 = 14.2688 ppmC 

NMHCd = FID THCd – r CH4

 * CH4d 

 = 3.532 – 1.15 * 2.261 

 = 0.9319 ppmC 

NMHCconc = NMHCe –NMHCd* (1 – 1/DF) 

 = 19.274 – 0.9319*( 1 – 1 / 14.2688) 

 = 18.407 ppmC 

NMHCmass1 = NMHCconc  NMHCdens  VMIX1 * 10-6

 = 18.407 * 16.33 17.44 * 3495 * 10-6

 = 1.0506 1.1220 g 

Similarly, for Phase 2, DF = 22.152 and NMHCmass2 = 0 

Similarly, for Phase 3, DF = 17.32632 and NMHCmass2 = 0.00256 g 

4. SPECIATED HYDROCARBON MASS EMISSIONS CALCULATION

* * * * 

 4.4. SAMPLE CALCULATION

4.4.1 Exhaust emissions from a gasoline vehicle are collected in three dilute 

exhaust sample bags and one dilution air (background) sample bag 

during the FTP. Gas chromatography is used to determine the benzene 

concentration of each bag sample. Calculate the weighted benzene 

mass emissions based on the following data: 
11

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

Test 

Phase 

HCe

(ppbC) 

HCd

(ppbC) 

FID THCe

(ppmC) 

CH4e

(ppmC) 

CO2e

(%) 

COem

(ppm) 

Ra

(%) 

VMIX 

(ft3

) 

Dphase n

(mile) 

1 500 25 98 6 1.20 280 28 2846 3.584 

2 100 25 22 4 0.95 87 25 4854 3.842 

3 120 25 29 5 1.07 101 24 2840 3.586 

For Phase 1: 

DF = 13.47 / [CO2e + (NMHCe + CH4e + COe ) * 10-4 ] 

 (see section 3, DF Calc.) 

 NMHCe = FID THCe - (rCH4 * CH4e ) 

 = 98 ppmC - (1.04 * 6 ppmC) 

 = 92 ppmC 

 CO = (1 - (0.01 + 0.005 * HCR) * CO2e - 0.000323 * Ra ) * COem

NOTE: If a CO instrument which meets the criteria specified in CFR 40, 

86.111 is used and the conditioning column has been deleted, COem must be 

substituted directly for COe . 

 = (1 - (0.01925) * 1.2% - 0.000323 * 28%) * 280 ppm 

 = 271 ppm 

 DF = 13.47 / [1.2% + (92 ppmC + 6 ppmC + 271 ppm) * 10-4 ] 

 = 10.89 

 HCconc = HCe - (HCd * (1 - (1 / DF))) 

 = 500 ppbC - (25 ppbC * (1 - (1 / 10.89))) 

 = 477 ppbC 

 Mol. Wt. of C6H6 = (6 * 12.01115) + (6 * 1.00797) 

 = 78.11472 g/mole 

 HCdens = (Mol. Wt. * conversion of liter to ft3

 ) / (Mol. Vol.) 

 = (78.11472 g/mole * 28.316 liter/ft3 ) / 24.055 liter/mole 

 = 91.952 g/ft3

 HCmass n = (HCconc * HCdens * VMIX * 10-6 ) / (Carbon No.) 

 HCmass 1 = (477 ppbC * 91.952 g/ft3

 * 2846 ft3 * 10-6 ) / 6 

 = 20.8 mg 

 Similarly, for Phase 2: HCcmass 2 = 5.7 mg 
12

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

 and for Phase 3: HCcmass 3 = 4.2 mg 

 Therefore, 

 

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phase3 phase2

mass3 mass2

phase1 phase2

mass1 mass2

wm D D

HC HC 0.57

D D

HC HC HC 0.43

 

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3.586 miles 3.842 miles

4.2mg 5.7mg 0.57

3.584 miles 3.842 miles

20.8mg 5.7mg HC 0.43 wm

 HCwm = 2.3 mg/mile (benzene weighted mass emissions) 

5. ALCOHOL MASS EMISSIONS CALCULATION

* * * * 

 5.4 SAMPLE CALCULATION 

5.4.1 Alcohol emissions from an E85 fueled vehicle are collected in three 

sets of dilute exhaust impingers and one set of dilution air impingers 

during the FTP. Gas chromatography is used to determine the alcohol 

concentration in each impinger. This is the same vehicle test as the 

example in section 3.3. Calculate the weighted ethanol mass 

emissions based on the following data, along with the data presented in 

section 3.3: 

Test 

Phase 

Ivolr

(mL) 

Iconce1

(μg/mL) 

Iconce2

(μg/mL) 

Ivolem

(liter) 

Iconcd1

(μg/mL) 

Iconcd2

(μg/mL) 

Ivoldm

(liter) 

Itempe

(

o

K) 

Itempd

(

o

K)

1 15 4.984 0.106 8.18 0 0 31.16 294.26 294.26 

2 15 0 0 14.65 0 0 31.16 294.26 294.26 

3 15 0 0 8.67 0 0 31.16 294.26 294.26 

Test Phase Dphase n

(mile) 

DF PB 

(mm HG)

VMIX (ft33) 

1 3.591 14.27 760 3495 

2 3.846 22.15 760 5799 

3 3.591 17.33 760 3484 

* * * * 
13

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

6. CARBONYL MASS EMISSIONS CALCULATIONS

* * * * 

 6.4. SAMPLE CALCULATION

6.4.1 Carbonyl emissions from an E85 vehicle are collected in three sets of 

dilute exhaust impingers and one set of dilution air impingers during 

the FTP. HPLC is used to determine the carbonyl mass in each 

impinger. This is the same vehicle test as the example in section 3.3. 

Calculate the weighted formaldehyde and acetaldehyde mass 

emissions based on the following data, along with the data presented in 

section 3.3: 

Test 

Phase 

Ivolc

(mLl) 

Formaldehyde Ivolem

(liter) 

Acetaldehyde Ivoldm

(liter) 

Itempe

(

o

K)

Itempd

(

o

K) Iconcce

(μg/mL) 

Iconccd

(μg/mL) 

Iconcce

(μg/mL) 

Iconccd

(μg/mL) 

1 4.4 0.387 0.006 8.47 4.114 0.006 8.23 294.26 294.26 

2 4.4 0.048 0.016 15.35 0.013 0.009 13.88 294.26 294.26 

3 4.4 0.016 0.006 9.01 0.012 0.005 8.16 294.26 294.26 

Test Phase Dphase n

(mile) 

DF PB 

(mm HG)

VMIX (ft3

3) 

1 3.591 14.27 760 3495 

2 3.846 22.15 760 5799 

3 3.591 17.33 760 3484 

* * * * 

7 NONMHC MASS EMISIONS CALCULATION 

* * * * 

 7.3 Sample Calculation 

Continuing from the same E85 test used in the alcohol and carbonyl calculations: 

Test Phase NMHCmass n

(g) 

Ethanolmass n 

(g) 

Formaldehydemassn 

(g) 

Acetaldehydemass n

(g) 

1 1.0506 

1.1220

0.09271 0.0197 0.212 

2 0 0 0.001457 0.000165 

3 0.00256 0 0.000472 0.000329 

and 

NMHCdens = 16.33 17.44 g/ft3
14

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

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dens

mass1

ROH dens

dens

mass1

mass1 mass1 dens r

RHO

RHO

r NMHC

ROH

ROH NONMHC NMHC NMHC

NONMHCmass1 = 1.0506 1.1220 – 16.33 17.44 g/ft3

 * ( 0.9271 g / 27.116 (g/ft3)) * 

0.756 

 – 16.33 17.44 g/ft3

 * ( 0.0197 g / 35.350 (g/ft3)) * 0 

 – 16.33 17.44 g/ft3 * ( 0.212 g / 25.929 (g/ft3)) * 0.5 

 = 1.0506 1.1220 – 0.4221 0.4508 – 0 – 0.0668 0.0713 

 = 0.5617 0.5999 g 

NONMHCmass2 = 0 – 16.33 17.44 g/ft3

 * ( 0 g / 27.116 (g/ft3)) * 0.756 

 – 16.33 17.44 g/ft3 * ( 0.001457 g / 35.350 (g/ft3)) * 0 

 – 16.33 17.44 g/ft3 * ( 0.000165 g / 25.929 (g/ft3)) * 0.5 

 = 0 – 0 – 0 – 0.0000525 

 = 0 g 

Note: Results that are less than zero are reported as zero. 

NONMHCmass3 = 0.00256 – 16.33 17.44 g/ft3

 * ( 0 g / 27.116 (g/ft3)) * 0.756 

 – 16.33 17.44 g/ft3 * ( 0.000472 g / 35.350 (g/ft3)) * 0 

 – 16.33 17.44 g/ft3 * ( 0.000329 g / 25.929 (g/ft3)) * 0.5 

 = 0.00256 – 0 – 0 – 0.000111 

 = 0.00249 g 

8 WEIGHTED HYDROCARBON MASS EMISSIONS CALCULATION 

* * * * 

 8.2 Sample calculation 

Continuing from the previous example: 

Test 

Phase 

NONMHCmass n

(g) 

Ethanolmass n

(g) 

Formaldehydemass n

(g) 

Acetaldehydemass n 

(g) 

Distance 

(mile) 

1 0.5999 

0.5617 

0.9271 0.019718 0.212 3.591 

2 0 0 0.001457 0.000165 3.846 

3 0.00249 0 0.000472 0.000329 3.591 

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3.591miles 3.846miles

0.00249 g 0 g 0.57

3.591miles 3.846miles

0.5999 g 0 g NONMHCwm 0.43

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

 







  

3.591miles 3.846 miles

0.0024 g 0 g 0.57

3.591miles 3.846 miles

0.5617 g 0 g NONMHCwm 0.43
15

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

NONMHCwm = 0.03266 0.03488 g/mile 

Similarly, Ethanolwm = 0.05360 g/mile 

Similarly, Formaldehydewm = 0.00137 g/mile 

Similarly, Acetaldehydewm = 0.01231 g/mile 

With all the above information, the weighted mass emissions of non-methane organic 

gas can be calculated: 

NMOG wm   NONMHC wm ROH wm RHOwm

NMOGwm = 0.03266 0.03488 g/mile + 0.05360 g/mile + 0.00137 g/mile + 0.01231 

g/mile 

 = 0.09994 0.102 g/mile 
16

As Amended: December 6, 2012 

Date of Hearing: November 15, 2012 

APPENDIX 1 

LIST OF COMPOUNDS 

CAS # COMPOUND MIR 

* * * * 

 Light End and Mid-Range Hydrocarbons

(Listed in approximate elution order) 

* * * * 

03404-61-3 3-methyl-1-hexene 4.564.41 

* * * *