# MEMORANDUM

To: Debbie Ottinger, EPA

CC: Don Wuebbles, University of Illinois

From: Mollie Averyt, Becky Ferenchiak, Mark Flugge, and K asey Knoell, ICF

Date: November 24, 2014

Re: Revised Analysis of Default GWPs for Fluorinated GHGs Repor ted Under the GHGRP

(Revised November, 2014)

This revised memorandum presents an updated summary of an ICF analysis to develop default Global Warming Potentials (GWPs) for fluorinated compounds without peer-reviewed GWPs. These default
GWPs have been evaluated for inclusion in the final rule, “Greenhouse Gas Reporting Program: Addition of Global Warming Potentials to the General Provisi ons and Amendments and Confidentiality Determinations for Fluorinated Gas Production” (EPA Docket No. EPA-HQ-OAR-2009-0927, hereinafter
referred to as “Final Rule to Add GWPs and Amend Su bpart L”). The purpose of the analysis is to:

1. Consider which sets of compounds should be used as the basis for default GWPs for the different groups of fluorinated GHGs whose GWPs do not appear on Table A-1,

2. Calculate the average and the standard deviation of the GWPs for these groups, and

3. Suggest possible default GWPs by rounding the avera ge for each group to one or two significant figures.

This analysis builds on two previous analyses prepa red for the proposed rules, “Greenhouse Gas Reporting Program: Amendments and Confidentiality D eterminations for Fluorinated Gas Production” (hereinafter referred to as “Proposed Amendments to Subpart L”), published on November 19, 2013 (78 FR 69337), and “Greenhouse Gas Reporting Program: A ddition of Global Warming Potentials” (hereinafter referred to as “Proposed Rule to Add G WPs”), published on July 31, 2014 (79 FR 44332). Those analyses were respectively entitled **Analysis of Potential Default GWPs for Fluorinated GHGs**  **Reported Under the GHGRP,** and **Revised Analysis of Default GWPs for Fluorinated G HGs Reported Under**  **the GHGRP (Revised July, 2014)** . They are available in EPA Docket No. EPA-HQ-OAR-2 009-0927. The second analysis included consideration of the comme nts received on the GWP-related provisions of the Proposed Amendments to Subpart L; this analysis add s consideration of the comments received on the Proposed Rule to Add GWPs.

The remainder of this memorandum is organized into the following sections:

I. Summary II. Analysis Method for Determining Default GWP Gro ups III. Comparison between Defaults and Estimated GWPs for Several F-GHGs IV. Evaluation of Analysis Method by Dr. Wuebbles a nd Recommendations V. Revisions to the Proposed Chemical-Specific and Default GWPs

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 2 

### VI. References Appendix A: F-GHGs by Fluorinated GHG Group

The complete results of the analysis are contained in the spreadsheet “Default GWP Chemical Groups_11-24-2014.xlsx.”

Please contact Mollie Averyt at 202-862-1569 ( mollie.averyt@icfi.com ) with any questions or comments.



# I. Summary

Through the Greenhouse Gas Reporting Program (GHGRP ), the U.S. Environmental Protection Agency (EPA) receives reports of emissions of numerous flu orinated greenhouse gases (GHGs) and heat transfer fluids (HTFs) that do not have GWPs listed on Table A-1, the GHGRP’s compendium of GWPs. EPA is adding chemical-specific and default GWPs to Table A-1 to address this situation. Specifically, EPA is adding approximately 100 chemical-specific GWPs pub lished by the Intergovernmental Panel on Climate Change (IPCC) in their Fifth Assessment Report (AR5 ) (Myhre et al. 2013) in the fall of 2013. For the fluorinated GHGs and HTFs reported under the GHGRP that do not have chemical-specific GWPs in either Table A-1 or AR5, EPA is adding default GWPs . These default GWPs will be assigned based on the fluorinated GHG group to which the fluorinated GHG and HTF belongs, based on chemical structure. Default GWPs will ensure that the atmospheric impac ts of all fluorinated GHGs and HTFs are reflected i n facility calculations and carbon dioxide equivalent (CO 2 

### e) emissions totals.

In developing the fluorinated GHG groups and associ ated default GWPs, the goal is to model the GWPs of compounds that belong to each group (but whose G WPs are not on Table A-1) with as much accuracy and precision as possible. EPA is applying the foll owing criteria to assess potential compound groups: (1) Collectively, the compound groups should span t he full range of atmospheric behavior (atmospheric lifetimes and GWPs) observed among fluorinated GHGs , (2) within each compound group, the compounds should be chemically similar and exhibit similar atmospheric behavior, and (3) compounds whose atmospheric behavior is likely to be differen t from that of any of the compounds whose GWPs are being modeled should be excluded from the calcu lation. However, numerical outliers should be included in the calculation when the possibility ex ists that such outliers may also occur among the fluorinated GHGs whose GWPs are being modeled.

As noted above, ICF previously performed two analys es based on these criteria to develop default GWPs. As shown in Table 1, the first set of default GWPs based on five fluorinated GHG groups was proposed in the Proposed Amendments to Subpart L fo r purposes of reporting emissions under subpart

L.

Table 1. Fluorinated GHG Groups and Associated Defa ult GWPs in Proposed Amendments to Subpart L

Fluorinated GHG Group GWP in Proposed
Amendments to Subpart L (100-yr) Average

GWP Standard

Deviation
of GWP Fully fluorinated GHGs 10,000 9,857 3,450 Saturated hydrofluorocarbons (HFCs) 2,200 2,187 3,3 46 Saturated hydrofluoroethers (HFEs) and saturated hydrochlorofluoroethers (HCFEs) a 

### 1,600 1,536 2,536

Unsaturated perfluorocarbons (PFCs), unsaturated HF Cs, unsaturated hydrochlorofluorocarbons (HCFCs), unsat urated HFEs, and fluorinated ketones 1 0.42 0.62

Other fluorinated GHGs b 

### 100 112 177

a The average GWP and standard deviation for this gr oup were revised from 1,559 and 2,551, respectively , after including 2- Chloro-1,1,2-trifluoro-1-methoxyethane, which was p reviously miscategorized in “Other fluorinated GHGs .”

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 3 b The average GWP and standard deviation for this gr oup were revised from 103 and 183, respectively, af ter removing fluorotelomer alcohols and fluorinated aldehydes, w hich were previously categorized in “Other fluorina ted GHGs,” which at the time was the most appropriate category.



### For this set of default GWPs as well as subsequent sets, EPA based the proposed default GWPs on the average of the chemical-specific GWPs of chemicals that belonged to that group and that were either on Table A-1 or are proposed to be added to Table A-1 under the Proposed Rule to Add GWPs. The fluorinated GHG groups have consistently been based primarily on chemical structure, which is correlated with atmospheric lifetime and GWP.

As discussed in the **Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP**  **(Revised July, 2014),** three commenters, DuPont, 3M, and the American Che mistry Council (ACC) provided comments regarding the chemical groups and associated GWPs of fluorinated gases in the Proposed Amendments to Subpart L. The commenters re quested that EPA split the third group (saturated HFEs and saturated HCFEs) into two, expa nd the fourth group (unsaturated PFCs, unsaturated HFCs, unsaturated HCFCs, unsaturated HFEs, and fluo rinated ketones), and add two additional groups,
fluorotelomer alcohols and fluorinated GHGs with ca rbon-iodine bonds, to increase the precision and accuracy of the default GWPs applied to the chemica ls in these groups. Two commenters also suggested separating compounds with GWPs near 10 (e .g., fluorinated alcohols other than fluorotelomer alcohols) from the remainder of the “ other” category.

These comments were reviewed and the fluorinated GH G groups and associated default GWPs were reevaluated for the Proposed Rule to Add GWPs. A br ief summary and analysis of the GWP-related comments on the Proposed Amendments to Subpart L ca n be found in the **Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRP**  **(Revised July, 2014)** . A detailed summary and response to all the comments on the Proposed Amendm ents to Subpart L is included in docket number
EPA-HQ-OAR-2009-0927.

In the Proposed Rule to Add GWPs, EPA proposed eigh t default GWP values based on fluorinated GHG groups. These default GWPs were proposed to be adde d to Table A-1 and to apply to fluorinated GHGs and HTFs not otherwise listed on Table A-1. The pro posed fluorinated GHG groups are listed in Table 2,
below.

Table 2. Fluorinated GHG Groups and Associated Defa ult GWPs for Proposed Rule to Add GWPs

Fluorinated GHG Group GWP in Proposed Rule to
Add GWPs (100-year)
Fully fluorinated GHGs 10,000 Saturated hydrofluorocarbons (HFCs) 2,200 Non-segregated saturated hydrofluoroethers (HFEs) Non-segregated saturated hydrochlorofluoroethers (H CFEs) 2,400

Partially segregated saturated hydrofluoroethers (H FEs) Partially segregated saturated hydrochlorofluoroeth ers (HCFEs) 200

Unsaturated perfluorocarbons (PFCs)

Unsaturated HFCs and HCFCs Unsaturated halogenated ethers Unsaturated halogenated esters
Fluorinated ketones Fluorinated aldehydes 1

Fluorotelomer alcohols 1

Fluorinated GHGs with one or more carbon-iodine bon d 1

Other fluorinated GHGs 110

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 4 

### In response to comments received on the Proposed Ru le to Add GWPs, EPA is making additional changes
to the default GWPs for the Final Rule to Add GWPs. First, the group of saturated HFCs is being divide d into two groups based on the number of carbon-hydro gen bonds in the compound (i.e., two or fewer carbon-hydrogen bonds and three or more carbon-hydr ogen bonds). Second, the group of saturated HFEs and HCFEs is being divided into three groups b ased on the number of carbon-hydrogen bonds in the compound (i.e., one carbon-hydrogen bond, two c arbon-hydrogen bonds, and three or more carbon-hydrogen bonds) rather than two groups based on the position of the fluorine atoms in the compound (segregated vs. partially segregated). Thi rd, the proposed “other” category is being divided into three groups: (1) Fluorinated acetates, carbon ofluoridates, and fluorinated alcohols other than fluorotelomer alcohols, (2) fluorinated formates, a nd (3) other fluorinated GHGs and HTFs. The details of this revised analysis are summarized in Section V.



# II. Analysis Method for Determining Default GWP Groups

In order to establish different compound groups and evaluate potential default GWPs for each group, ICF analyzed the chemical structure, GWPs, and atmo spheric lifetimes of the fluorinated GHGs with peer-reviewed GWPs. The F-GHGs with peer-reviewed G WPs include the compounds on Table A-1 and the compounds in AR5. As noted above, ICF also cons idered the comments on the Proposed Amendments to Subpart L and on the Proposed Rule to Add GWPs.

Ninety seven F-GHGs from AR5 and one F-GHG from the IPCC Fourth Assessment Report (AR4) (Forster et al. 2007) (i.e., 98 F-GHGs in total) that are no t included in the current Table A-1 are included in the current analysis. For compounds that are included i n the current Table A-1, ICF used the GWPs from Table A-1 as they were updated in the “2013 Revisio ns to the Greenhouse Gas Reporting Rule and Proposed Confidentiality Determinations for New or Substantially Revised Data Elements; Final Rule” (7 8 FR 71904; November 3, 2013), with the exception of sevoflurane, for which the AR5 GWP was used. For compounds that are included only in AR5, ICF used t he GWP from AR5 in the analysis, with the exception of several very short-lived compounds who se GWPs were listed in AR5 as “<1.” In order to increase the accuracy of the default GWP analysis, precise GWPs were calculated and used in this analysis for these compounds using the atmospheric lifetime and the corrected radiative efficiency provided in the AR5.

The current analysis focuses on 12 main model group s (Table 3). The details of this revised analysis a re summarized in Section V. As was the case for the fl uorinated GHG groups included in the Proposed Amendments to Subpart L and in the Proposed Rule to Add GWPs, these groups exclude compounds that are chemically different (i.e., that are not f luorocarbons and are therefore chemical outliers) f rom the compounds whose GWPs are being modeled, but the y include compounds whose GWPs are unusually high or low (i.e., numerical outliers). A lso like the fluorinated GHG groups included in the Proposed Amendments to Subpart L and the Proposed R ule to Add GWPs, the groups include chemically similar chlorine-containing compounds that are defi ned as fluorinated GHGs (i.e., are not regulated as ozone-depleting compounds under 40 CFR part 82).

The average and standard deviation of the GWPs of t he compounds within each model group were calculated. The suggested GWP for each model group is equal to the average GWP of the F-GHGs within that model group, rounded to either one or two sign ificant figures.

Table 3 presents the fluorinated GHG groups with th e corresponding average, standard deviation, and relative standard deviation of the GWPs for each gr oup. As can be seen by comparing Table 3 to Table 1

, the additions and changes to the fluorinated GHG gr oups that were included in the Proposed

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 5 

### Amendments to Subpart L are likely to improve the a ccuracy and precision of the default GWPs. This improvement is driven by the relationship between t he structural criteria used to break out the new groups (and subgroups) and atmospheric lifetime. As discussed further in the **Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRP**  **(Revised July, 2014)** and in the **Analysis of Atmospheric Lifetimes, Radiative Efficiencies, and**  **Global Warming Potentials of Saturated Hydrofluoroethers by Number of Carbon-Hydrogen and**  **Carbon-Fluorine Bonds** (both available in Docket EPA-HQ-OAR-2009-0927), atmospheric lifetime is the key factor in determining the 100-year GWPs of
most fluorinated GHGs. 1



### Table 3. Average, Standard Deviation, and Relative Standard Deviation of GWPs of Fluorinated GHG Groups

Fluorinated GHG Group Default

GWP Average

GWP Standard

Deviation Relative

Standard

Deviation Number

of
Chemicals in Group
Fully fluorinated GHGs and HTFs 10,000 9,857 3,450 35% 15 Saturated hydrofluorocarbons (HFCs) with two or fewer carbon-hydrogen bonds 3,700 3,657 4,264 117% 12

Saturated hydrofluorocarbons (HFCs) with three or more carbon-hydrogen bonds 930 928 1,563 169% 14

Saturated HFEs and HCFEs with one carbonhydrogen bond 5,700 5,680 5,629 99% 5

Saturated HFEs and HCFEs with two carbonhydrogen bonds 2,600 2,616 2,155 82% 19

Saturated HFEs and HCFEs with three or more carbon-hydrogen bonds 270 267 255 96% 36

Fluorinated formates 350 349 178 51% 8 Fluorinated acetates, carbonofluoridates, and
fluorinated alcohols other than fluorotelomer
alcohols 30 29 45 154% 22

Unsaturated PFCs 1 0.66 0.96 146% 6

Unsaturated HFCs and unsaturated HCFCs 1 0.38 0.51 134% 14
Unsaturated halogenated ethers 1 0.11 - - 2 Unsaturated halogenated esters 1 N/A N/A N/A 0

Fluorinated ketones 1 0.11 - - 1
Fluorinated aldehydes 1 0.01 - - 1

Fluorotelomer alcohols 1 0.32 0.10 31% 4

Fluorinated GHGs with one or more carbon-iodine
bonds 1 0.4 - - 1

Other fluorinated GHGs and HTFs 2,000 2,050 4,042 1 97% 164 a

N/A = Not available

a The default GWP for the “other fluorinated GHGs an d HTFs” group is based on the average GWP of all th e compound on Table A-1 and those proposed to be added to Table A-1.

1 The partial exception to this rule is the group of fully fluorinated GHGs. While the long atmospheric lifetimes of fully fluorinated GHGs give this group the highest averag e GWP of any group, those lifetimes are so long tha t differences between the lifetimes have relatively little impact on the differences between the 100-year GWPs of the fully fluorinated GHGs. Whether a fully fluorinated GHG has an atmospheric lifetime of 1,000 years or 2,000 years, most emissions of t hat gas will still remain in the atmosphere after 100 years.

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 6 

### In addition, potential default GWPs for the fluorin ated GHG groups were developed by also evaluating GWPs of the F-GHGs from AR5 only. This analysis can be found in the **Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRP (Revi**  **sed July, 2014)**

. Figure 1 below is a semi-log histogram that illustr ates the number of chemicals in each F-GHG group or subgroup whose GWPs fall within different orders of magnitude. The left-most bar represents the number of compounds with GWPs between 0.001 and 0.0 1; the second bar represents compounds with GWPs between 0.01 and 0.1; etc.Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRPPage 7Figure 1. Histogram of F-GHG Group and Subgroup GWPs051015202530354045500.001 to0.010.01 to 0.1 0.1 to 1 1 to 10 10 to 100 100 to1,0001,000 to10,00010,000and aboveGWPFully Fluorinated GHGsSaturated HFCs with 2 or fewer carbon-hydrogen bondsSaturated HFCs with 3 or more carbon-hydrogen bondsSaturated HFEs and HCFEs with 1 carbon-hydrogenbondSaturated HFEs and HCFEs with 2 carbon-hydrogenbondsSaturated HFEs and HCFEs with 3 or more carbonhydrogen bondsFluorinated formatesFluorinated acetates, carbonofluoridates, andfluorinated alcohols other than fluorotelomer alcoholsUnsaturated PFCsUnsaturated HFCs and HCFCsUnsaturated Halogenated EthersUnsaturated Halogenated EstersFluorinated KetonesFluorinated AldehydesFluorotelomer AlcoholsCompounds including one or more carbon-iodine bonds

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 8 

# III. Comparison between Defaults and Estimated GWPs for Several
F-GHGs

ICF tested the accuracy of the default GWPs based o n chemical groups by comparing the default GWPs to: (1) The GWPs of F-GHGs with documented (but not peer-reviewed) GWPs provided by 3M and made available for comment through the April 5, 2013 Not ice of Data Availability (NODA) (78 FR 20632) (Tabl e 4) and (2) the GWPs of F-GHGs with documented (but not peer-reviewed) GWPs in the Proposed 2013 Revisions rule (Table 5). Chemical-specific GWPs fo r these fluorinated GHGs are not included in the Fi nal
Rule to Add GWPs.

In Table 4, eight compounds with documented GWPs pr ovided by 3M were categorized into the fluorinated GHG groups and assigned a default GWP:

• The first six compounds would be assigned to the “f ully fluorinated GHGs and HTFs” group and have an average GWP of 9,452. This average GWP is s imilar to the suggested default GWP for “fully fluorinated GHGs and HTFs”, which is equal t o 10,000.

• The remaining two compounds provided by 3M, HFE-730 0 and HFE-7500, have an average GWP
of 205. Both HFE-7300 and HFE-7500 are saturated HF Es with three or more carbon-hydrogen bonds and have atmospheric lifetimes of 3.8 and 2.2 years, respectively. Therefore, these two compounds could be assigned to the saturated HFEs a nd HCFEs with three or more carbonhydrogen bonds, which has a suggested default GWP o f 270.

Table 4. 3M Company Fluorinated GHGs GWPs and Defau lt GWP Comparison

Potential Fluorinated GHG

Group Chemical Designation or Common

Name Chemical
Formula 3M

Submitted

GWP Default

GWP

Fully fluorinated GHGs and HTFs Perfluorotripropyl amine (PTPA) C 9 

### F 21 

### N 8,690 10,000

Fully fluorinated GHGs and HTFs Perfluorotributyl a mine (PTBA) C 12 

### F 27 

### N 9,020 10,000

Fully fluorinated GHGs and HTFs Perfluorotriamyl am ine (PTAA) C 15 

### F 33 

### N 8,900 10,000

Fully fluorinated GHGs and HTFs Perfluoromethyl mor pholine (PMM) C 5 

### F 11 

### NO 9,500 10,000

Fully fluorinated GHGs and HTFs Perfluoroisopropyl morpholine (PIPM) C 7 

### F 15 

### NO 11,000 10,000

Fully fluorinated GHGs and HTFs 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-
hexadecafluorooxonane C 8 

### F 16 

### O 9,600 10,000

Saturated HFEs and HCFEs with three or more carbon-hydrogen
bonds 1,1,1,2,2,3,4,5,5,5-decafluoro-3- methoxy-4-trifluoromethyl-pentane (HFE-7300) C 7 

### H 3 

### F 13 

### O 310 270

Saturated HFEs and HCFEs with three or more carbon-hydrogen
bonds 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6- dodecafluoro-2-trifluoromethyl-hexane (HFE-7500) C 9 

### H 5 

### F 15 

### O 100 270



### As shown in Table 5, eleven compounds with document ed (but not peer-reviewed) GWPs in the Proposed 2013 Revisions Rule that are not included in the Final Rule to Add GWPs were also categorized into the fluorinated GHG groups and assigned a defa ult GWP:

• Two of the compounds that would be categorized as “ unsaturated halogenated ethers”, which both had estimated GWPs of 3, would be assigned a d efault GWP of 1.

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 9 

### • Six of the compounds that would be categorized as “ fluorinated GHGs with one or more carboniodine bonds”, whose average estimated GWP was 2.3, would be assigned a default GWP of 1.

• The GWP for 1H,1H,2H,2H-perfluorohexan-1-ol (42–AL) was listed as 2 in the Proposed 2013 Revisions Rule; this compound would be categorized as a “fluorotelomer alcohol” and assigned a
default GWP of 1.

• The GWP for FK–6–1–12 was listed as 1 in the Propos ed 2013 Revisions Rule and this compound would be categorized as a “fluorinated ketone” and assigned a default GWP of 1.

• The GWP for carbonyl fluoride was listed as 2 in th e 2013 Revisions Rule; this compound would be categorized as an “other fluorinated GHGs and HT Fs” and assigned a default GWP of 2,000.

With the exception of the default GWP for carbonyl fluoride, the default GWPs assigned to these compounds are quite close to their previously estim ated GWPs. The defaults for the unsaturated compounds, fluorotelomer alcohols, and compounds wi th carbon-iodine bonds are lower than the previously estimated GWPs for these compounds becau se the defaults reflect corrections made to the radiative efficiencies of these compounds in AR5. T hese corrections lower the radiative efficiencies t o account for the fact that the compounds are very sh ort-lived and are therefore not well-mixed in the atmosphere.

Table 5. Fluorinated GHG GWPs in Proposed 2013 Revi sions Rule Not Included in Final Rule

Potential Fluorinated GHG

Group Chemical Designation or

Common Name Chemical Formula Proposed

GWP Default

GWP
Unsaturated halogenated ethers Perfluoropropyl viny l ether C 5 

### F 10 

### O 3 1
Unsaturated halogenated ethers Perfluoroethyl vinyl ether C 4 

### F 8 

### O 3 1

Fluorinated GHGs with one or
more carbon-iodine bonds Perfluorethyl iodide (2–I) C 2 

### F 5 

### I 3 1

Fluorinated GHGs with one or
more carbon-iodine bonds Perfluorbutyl iodide (PFBI, 42–I) C 4 

### F 9 

### I 3 1

Fluorinated GHGs with one or
more carbon-iodine bonds Perfluorhexyl iodide (6–I) CF 3 

### CF 2 

### CF 2 

### CF 2 

### CF 2 

### CF 2 

### IC

6 

### F 13 

### I 2 1

Fluorinated GHGs with one or
more carbon-iodine bonds Perfluoroctyl iodide (8–I) C 8 

### F 17 

### I 2 1

Fluorinated GHGs with one or
more carbon-iodine bonds 1,1,1,2,2-pentafluoro-4- iodo butane (22–I) C 4 

### H 4 

### F 5 

### I 2 1

Fluorinated GHGs with one or
more carbon-iodine bonds 1,1,1,2,2,3,3,4,4-
nonafluoro-6-iodo hexane

(42– I) C 6 

### H 4 

### F 9 

### I 2 1

Fluorotelomer alcohols 1H,1H, 2H,2Hperfluorohexan-1-ol (42–

AL) C 6 

### H 5 

### F 9 

### O 5 1

Fluorinated ketones FK–6–1–12/NovecTM 774,

C7 Fluoroketone C 7 

### F 14 

### O Chemical
Blend 1 1

Other fluorinated GHGs and

HTFs Carbonyl fluoride COF 2 

### 2 2,000



# IV. Evaluation of Analysis Method by Dr. Wuebbles and
Recommendations

Dr. Donald J. Wuebbles evaluated the overall approa ch of assigning a default GWP to target compounds from certain compound groups based on the average G WP of similar “model” groups of compounds,

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 10 

### and noted that although there are significant uncer tainties associated with this approach due to the range of GWPs observed within each group of model c ompounds, this may be the most viable option for
EPA based on the available information and time con straints. Dr. Wuebbles recommended developing a technique for assigning default GWPs based on model ing, or by developing a default estimate based on the relative amounts of fluorine, chlorine, and hyd rogen in each compound. Both techniques would require additional research, and the technique base d on modeling would be a major research effort. Dr. Wuebbles also suggested considering compounds with double carbon-carbon bonds (which are expected to all have short lifetimes) as a potentia l model group. Based on this suggestion, a model group consisting of separate sub-groups for unsatur ated PFCs, HFCs and HCFCs, halogenated ethers, and halogenated esters was developed. 2 

### Dr. Wuebbles also noted that the IPCC process for developing Assessment Reports (e.g., AR4) is not designed to b e the sole arbiter of “official” GWP values, and ot her sources of published (i.e., peer-reviewed) literatu re (e.g., WMO 2010) should be considered when establishing default GWP estimates. In addition, as a result of this discussion, numerical outliers ar e not excluded when calculating the suggested (i.e., aver age) model group GWP, since the GWPs for unknown target compounds might equally be outliers themselv es.

Dr. Wuebbles also reviewed the comments that were r eceived on the Proposed Amendments to Subpart L. Dr. Wuebbles agreed with the analyses co nducted by DuPont because their suggestions are well-defined from a physical chemistry standpoint a nd also because Hodnebrog et al. 2013 is the proper source to use for such analyses as is it the basis for the GWPs presented in AR5. Dr. Wuebbles also no ted that 3M’s suggestion to use the median GWP of a gro up of compounds (i.e., saturated HFEs) to assign a default GWP for that particular group is inappropri ate, as the compounds with very high GWPs would be assigned a much smaller GWP value.

2 During a conference call on May 9, 2013 between ICF , EPA, and Dr. Wuebbles to have an intermediary dis cussion regarding the default GWP analysis, Dr. Wuebbles communicated that compounds with a lifetime greater than 1 year should be considered long-lived regardless of their correspon ding GWP.

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 11 

# V. Revisions to the Proposed Chemical-Specific and Def ault GWPs

EPA is finalizing the addition of both chemical-spe cific and default GWPs following consideration of comments submitted on the Proposed Rule to Add GWPs , which were received during the comment period that ended on September 2, 2014. This sectio n summarizes those comments and revisions that were made to the rule in response to the comments r eceived.



## a. Duplicate Compounds on Table A-1 One commenter observed that the proposed chemical-s pecific GWPs in Table A-1 included some duplicate compounds with different GWPs. In the fin al Table A-1, five duplicate compounds were removed. Two sets of duplicates resulted from the i nadvertent proposed addition to Table A-1 of a GWP for a compound that already had a GWP listed. These included two fluorinated alcohols with the CAS numbers 422–05–9 and 920–66–1. In these cases, the previously listed GWPs, based on AR4, are retained. Three sets of duplicates came from AR5. T hese included two HFEs and one fluorinated alcohol with the CAS numbers 173350–37–3, 205367–61–9, and 375–01–9, respectively. In these cases, the average of the two GWPs was used, because the super iority of one GWP source over the other could not
be determined.



## b. Default GWP Groups Three changes to the proposed fluorinated GHG group s and default GWPs were made. These changes
result in the creation of four additional fluorinat ed GHG groups and default GWPs, increasing the tota l number of default GWPs from eight to twelve. All of the changes are expected to increase the accuracy and precision of the default GWPs.

First, the group of saturated HFCs is being divided into two groups based on the number of carbonhydrogen bonds in the compound. Second, the group o f saturated HFEs and HCFEs is being divided into three groups based on the number of carbon-hydrogen bonds in the compound rather than two groups based on the position of the fluorine atoms in the compound (segregated vs. partially segregated). The number of carbon-hydrogen bonds in each saturated H FC and HFE (and HCFE) is significantly correlated (negatively) with the atmospheric lifetime and GWP of that compound. For the saturated HFEs, the number of carbon-hydrogen bonds predicts the GWP mo re precisely than does the position of the fluorine atoms in the compound. Moreover, the numbe r of carbon-hydrogen bonds in each compound is likely to be known, facilitating the correct catego rization and default GWP selection for each saturat ed HFC or HFE that does not have a chemical-specific G WP on Table A-1. This structure clearly establishes groups of saturated HFCs and HFEs that have similar GWPs and sets considerably more precise default GWPs for these groups.

Finally, the proposed “other” category is being div ided into three groups:

(1) Fluorinated acetates, carbonofluoridates, and fluor inated alcohols other than fluorotelomer alcohols, (2) Fluorinated formates, and (3) Other fluorinated GHGs and HTFs.

A previous analysis, described in more detail in Ap pendix D, Part i, of **Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRP (Revi**  **sed July, 2014),** indicated that the fluorinated formates had significantly higher GWPs than most of the other specific compound types in the “other” group. The average GWP for the formates is about 35 0 while the average GWP for the other compounds comprising the “other” group is 30. Based on sugges tions received from commenters to separate the “other” group into different categories because of the relatively large range of GWPs included in the

### Revised Analysis of Default GWPs for Fluorinated GH Gs Reported Under the GHGRP Page 12 

### group, the Final Rule to Add GWPs is separating the specific compound types that were formerly in the “other” category into two groups. A default GWP of 350 is established for fluorinated formates, while a default of 30 is established for fluorinated acetat es, carbonofluoridates, and fluorinated alcohols ot her than fluorotelomer alcohols. This approach establis hes default GWPs that better reflect the average GWPs of both of the new, smaller groups. The new de fault GWPs differ by more than an order of magnitude, considerably increasing their precision for their respective groups.

Finally, a separate group for fluorinated GHGs that do not fall into any of the specific fluorinated G HG groups is being established and assigned a default GWP of 2,000, which is based on the average for all fluorinated GHGs. This “catch-all” group, which ret ains the title “Other fluorinated GHGs and HTFs,” includes types of fluorinated GHGs and HTFs whose G WPs have not been studied. A default GWP of 2,000 more appropriately represents such fluorinate d GHGs than the previously proposed GWP of 110, which was based on the GWP values for a small, pote ntially unrepresentative subset of fluorinated GHGs (i.e., fluorinated acetates, fluoridates, fluo rinated alcohols other than fluorotelomer alcohols, and fluorinated formates). Where the GWPs of particular fluorinated GHG groups have not been published in the peer-reviewed literature, it is likely they may fall anywhere on the continuum of GWPs measured for the fluorinated GHGs in this analysis. Therefor e, a default GWP of 2,000 will be used for any fluorinated GHG that cannot be categorized in any o f the default GWP groups and/or whose GWP is not

on Table A-1.



# VI. References

Forster, P., V. Ramaswamy, P. Artaxo, T. Berntsen, R. Betts, D.W. Fahey, J. Haywood, J. Lean, D.C. Low e, G. Myhre, J. Nganga, R. Prinn, G. Raga, M. Schulz a nd R. Van Dorland. 2007. Changes in Atmospheric Constituents and in Radiative Forcing. **In: Climate Change 2007:The Physical Science Basis. Contribution**  **of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change**  [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marqui s, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingd om and New York, NY, USA.

Hodnebrog, O. et al. 2013. Global Warming Potential s and Radiative Efficiencies of Halocarbons and Related Compounds: A Comprehensive Review. **Reviews of Geophysics** , 51.

Myhre, G., D. Shindell, F.A. Breon, W. Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Ta kemura and H. Zhang, 2013: Anthropogenic and Natural Radiative Forcing. **In: Climate Change 2013: The Physical Basis. Contribution of Working Group I**  **to the Fifth Assessment Report of the Intergovernme ntal Panel on Climate Change**  [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]

. Cambridge University Press, Cambridge, United Kingd om and New York, NY, USA.

Wuebbles, Don. 2014. Transcribed Correspondence wit h Don Weubbles on March 14, 2014.Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRPPage 13Appendix A: F-GHGs by Fluorinated GHG GroupTrade NameChemical Designation or Common NameCAS No.Chemical FormulaProposedGWPGWP SourceFully fluorinated GHGsPFPMIE perfluoropolymethylisopropyl ether 69991-67-9 CF3OCF(CF3)CF2OCF2OCF310,300 AR4/Table A-1PFC–14 Perfluoromethane 75–73–0 CF47,390 AR4/Table A-1PFC–9–1–18 Perfluorodecalin (mixed) 306–94–5 C10F187,500 AR4/Table A-1PFC–218 Perfluoropropane 76–19–7 C3F88,830 AR4/Table A-1PFC–3–1–10 Perfluorobutane 355–25–9 C4F108,860 AR4/Table A-1PFC–4–1–12 Perfluoropentane 678–26–2 C5F129,160 AR4/Table A-1PFC–5–1–14 Tetradecafluorohexane 355–42–0 C6F149,300 AR4/Table A-1PFC-6-1-12 Hexadecafluoroheptane 335-57-9 C7F16, CF3(CF2)5CF37,820 AR5PFC-7-1-18 Octadecafluorooctane 307-34-6 C8F18, CF3(CF2)6CF37,620 AR5PFC-318 Perfluorocyclobutane 115–25–3 c-C4F810,300 AR4/Table A-1PFC–116 Perfluoroethane 76–16–4 C2F612,200 AR4/Table A-1PFC–c216 Perfluorocyclopropane 931–91–9 c-C3F617,340 AR4/Table A-1Perfluorodecalin (cis) 60433-11-6 cis-C10F187,240 AR5Perfluorodecalin (trans) 60433-12-7 trans-C10F186,290 AR5Trifluoromethyl sulphur pentafluoride 373–80–8 SF5CF317,700 AR4/Table A-1Saturated HFCs with two or fewer carbon-hydrogen bondsHFC-227ca 1,1,1,2,2,3,3-Heptafluoropropane 2252-84-8 CF3CF2CHF2 2,640 AR5HFC–125 354–33–6 CHF2CF3 3,500 AR4/Table A-1HFC-329p 1,1,1,2,2,3,3,4,4-Nonafluorobutane 375-17-7 CHF2CF2CF2CF3 2,360 AR5HFC–227ea 431–89–0 C3HF7 3,220 AR4/Table A-1HFC–23 75–46–7 CHF3 14,800 AR4/Table A-1HFC–43–10mee 138495–42–8 CF3CFHCFHCF2CF3 1,640 AR4/Table A-1HFC–134 359–35–3 CHF2CHF2 1,100 AR4/Table A-1HFC–236ea 431–63–0 CHF2CHFCF3 1,370 AR4/Table A-1HFC–236cb 677–56–5 CH2FCF2CF3 1,340 AR4/Table A-1HFC–236fa 690–39–1 C3H2F6 9,810 AR4/Table A-1HFC–32 75–10–5 CH2F2 675 AR4/Table A-1HFC–134a 811–97–2 CH2FCF3 1,430 AR4/Table A-1Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRPPage 14Trade NameChemical Designation or Common NameCAS No.Chemical FormulaProposedGWPGWP SourceSaturated HFCs with three or more carbon-hydrogen bondsHFC-245cb 1,1,1,2,2-Pentafluoropropane 1814-88-6 CF3CF2CH3 4,620 AR5HFC-245ea 1,1,2,3,3-Pentafluoropropane 24270-66-4 CHF2CHFCHF2 235 AR5HFC–143a 420–46–2 C2H3F3 4,470 AR4/Table A-1HFC–143 430–66–0 C2H3F3 353 AR4/Table A-1HFC-245eb 1,1,1,2,3-Pentafluoropropane 431-31-2 CH2FCHFCF3 290 AR5HFC–245fa 460–73–1 CHF2CH2CF3 1,030 AR4/Table A-1HFC–41 593–53–3 CH3F 92 AR4/Table A-1HFC–245ca 679–86–7 C3H3F5 693 AR4/Table A-1HFC–152 624–72–6 CH2FCH2F 53 AR4/Table A-1HFC–152a 75–37–6 CH3CHF2 124 AR4/Table A-1HFC–161 353–36–6 CH3CH2F 12 AR4/Table A-1HFC–365mfc 406–58–6 CH3CF2CH2CF3 794 AR4/Table A-1HFC-263fb 1,1,1-Trifluoropropane 421-07-8 CH3CH2CF376 AR5HFC-272ca 2,2-Difluoropropane 420-45-1 CH3CF2CH3 144 AR5Saturated HFEs and HCFEs with one carbon-hydrogen bondHFE–329mcc2 1,1,1,2,2-Pentafluoro-2-(1,1,2,2-tetrafluoroethoxy)ethane 134769-21-4 CHF2CF2OCF2CF3 919 AR4/Table A-1HFE–227ea 2356–62–9 CF3CHFOCF3 1,540 AR4/Table A-11,1,1,2,2,3,3-Heptafluoro-3-(1,2,2,2-tetrafluoroethoxy)-propane3330-15-2 CF3CF2CF2OCHFCF3 6,490 AR5HFE–125 (difluoromethoxy)(trifluoro)methane 3822–68–2 CHF2OCF3 14,900 AR4/Table A-1HFE-329me3 1,1,1,2,3,3-Hexafluoro-3-(trifluoromethoxy)propane 428454-68-6 CF3CFHCF2OCF3 4,550 AR5Saturated HFEs and HCFEs with two carbon-hydrogen bondsHCFE-235ca2(enflurane)2-Chloro-1-(difluoromethoxy)-1,1,2-trifluoroethane13838-16-9 CHF2OCF2CHFCl 583 AR5HFE–338mcf2 1,1,1,2,2-Pentafluoro-2-(2,2,2-trifluoroethoxy)ethane 156053-88-2 CF3CH2OCF2CF3 552 AR4/Table A-1HFE–134 1691–17–4 CHF2OCHF2 6,320 AR4/Table A-1HG-031,1,3,3,4,4,6,6,7,7,9,9,10,10,12,12-Hexadecafluoro-2,5,8,11-tetraoxadodecane173350-37-3 HF2C-(OCF2CF2)3-OCF2H 3,670 AR51,1,3,3,4,4,6,6,7,7,9,9,10,10,12,12,13,13,15,15-eicosafluoro-2,5,8,11,14-Pentaoxapentadecane173350-38-4 HCF2O(CF2CF2O)4CF2H 3,630 AR5HG-30 1,1,3,3,5,5,7,7,9,9-Decafluoro-2,4,6,8-tetraoxanonane 188690-77-9 HF2C-(OCF2)3-OCF2H 7,330 AR5Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRPPage 15Trade NameChemical Designation or Common NameCAS No.Chemical FormulaProposedGWPGWP SourceHFE–338pcc13(HG–01)1,2-Bis(difluoromethoxy)-1,1,2,2-tetrafluoroethane188690–78–0 CHF2OCF2CF2OCHF2 1,500 AR4/Table A-1HFE–236fa 1,1,1-Trifluoro-2-(trifluoromethoxy)ethane 20193–67–3 CF3CH2OCF3 487 AR4/Table A-1HG-021-(Difluoromethoxy)-2-(2-(difluoromethoxy)-1,1,2,2-tetrafluoroethoxy)-1,1,2,2-tetrafluoroethane205367-61-9 HF2C-(OCF2CF2)2-OCF2H 3,825 AR5Trifluoro(fluoromethoxy)methane 2261-01-0 CH2FOCF3751 AR5HG-20(Difluoromethoxy)((difluoromethoxy)difluoromethoxy)difluoromethane249932-25-0 HF2C-(OCF2)2-OCF2H 5,300 AR5HG-211,1,3,3,5,5,7,7,8,8,10,10-Dodecafluoro-2,4,6,9-tetraoxadecane249932-26-1HF2C-OCF2CF2OCF2OCF2O-CF2H3,890 AR5HFE–338mmz1 2-(Difluoromethoxy)-1,1,1,3,3,3-hexafluoropropane 26103-08-2 (CF3)2CHOCHF2 380 AR4/Table A-1Isoflurane(HCFE–235da2)2-chloro-2-(difluoromethoxy)-1,1,1-trifluoro-ethane26675-46-7 C3H2ClF5O 350 AR4/Table A-1HFE-236ca 1-(Difluoromethoxy)-1,1,2,2-tetrafluoroethane 32778-11-3 CHF2OCF2CHF2 4,240 AR5Desflurane(HFE–236ea2)2-(Difluoromethoxy)-1,1,1,2-tetrafluoroethane 57041-67-5 CHF2OCHFCF3 989 AR4/Table A-1HFE–236ca12(HG–10)Bis(difluoromethoxy)difluoromethane 78522-47-1 CHF2OCF2OCHF2 2,800 AR4/Table A-11,1,2-Trifluoro-2-(trifluoromethoxy)-ethane 84011-06-3 CHF2CHFOCF3 1,240 AR5HFE–43–10pccc(H–Galden1040x)1-(Difluoromethoxy)-2-[(difluoromethoxy)(difluoro)methoxy]-1,1,2,2-tetrafluoroethaneE1730133 CHF2OCF2OC2F4OCHF2 1,870 AR4/Table A-1Saturated HFEs and HCFEs with three or more carbon-hydrogen bondsHFE-449sl,(HFE-7100)Isomer blend163702–07–6 C4F9OCH3 297 AR4/Table A-1HFE–347pcf2 1,1,2,2-Tetrafluoro-1-(2,2,2-trifluoroethoxy)ethane 406-78-0 CHF2CF2OCH2CF3 580 AR4/TableA-1Sevoflurane(HFE-347mmz1)2-(Difluoromethoxy)-1,1,1,3,3,3-hexafluoropropane 28523-86-6 (CF3)2CHOCH2F 216 AR5HFE–347mcf2 1-(2,2-Difluoroethoxy)-1,1,2,2,2-pentafluoroethane 171182-95-9 CHF2CH2OCF2CF3 374 AR4/Table A-1HFE–245fa2 2-(Difluoromethoxy)-1,1,1-trifluoroethane 1885-48-9 CHF2OCH2CF3 659 AR4/Table A-1HFE–347mmy1 1,1,1,2,3,3,3-Heptafluoro-2-methoxypropane 22052–84–2 CH3OCF(CF3)2 343 Table A-1Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRPPage 16Trade NameChemical Designation or Common NameCAS No.Chemical FormulaProposedGWPGWP SourceHFE–245cb2 1,1,1,2,2-Pentafluoro-2-methoxy-ethane 22410-44-2 CF3CF2OCH3 708 AR4/Table A-1HFE–347mcc3 Heptafluoropropyl methyl ether 375–03–1CH3OCF2CF2CF3 575 AR4/Table A-11,1,2,2-Tetrafluoro-1-(fluoromethoxy)ethane 37031-31-5 CH2FOCF2CF2H 871 AR5HFE–143a trifluoromethoxymethane 421–14–7 CH3OCF3 756 AR4/Table A-1Difluoro(fluoromethoxy)methane 461-63-2 CH2FOCHF2617 AR5HFE–245fa1 1,1-Difluoro-2-(trifluoromethoxy)ethane84011-15-4 CHF2CH2OCF3 286 AR4/Table A-1HFE–356mmz1 1,1,1,3,3,3-Hexafluoro-2-methoxypropane13171-18-1 C4H4F6O 27 Table A-1HFE–356pcc3 1,1,2,2,3,3-Hexafluoro-1-methoxypropane160620-20-2 CH3OCF2CF2CHF2 110 AR4/Table A-1HFE-356mff2 BIS(2,2,2-TRIFLUOROETHYL) ETHER 333-36-8 CF3CH2OCH2CF3 17 AR5HFE–356pcf3 3-(difluoromethoxy)-1,1,2,2-tetrafluoropropane 35042–99–0 CHF2OCH2CF2CHF2 502 AR4/Table A-1Difluoro(methoxy)methane 359-15-9 CH3OCHF2 144 AR5HFE–356mec3 1,1,1,2,3,3-Hexafluoro-3-methoxypropane382-34-3 CH3OCF2CHFCF3 101 AR4/Table A-12-Chloro-1,1,2-trifluoro-1-methoxyethane 425-87-6CH3OCF2CHFCl 122 AR5HFE–254cb1 1,1,2,2-Tetrafluoro-1-methoxyethane 425-88-7 CH3OCF2CHF2 359 AR4/Table A-1Fluoro(fluoromethoxy)methane 462-51-1 CH2FOCH2F 130 AR5HFE–356pcf2 1-(2,2-Difluoroethoxy)-1,1,2,2-tetrafluoroethane 50807-77-7 CHF2CH2OCF2CHF2 265 AR4/TableA-1HFE-569sf2,(HFE-7200)Isomer blend1-Ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane 163702-05-4 C4F9OC2H5 59 AR4/Table A-1HFE-365mcf2 1-Ethoxy-1,1,2,2,2-pentafluoroethane 22052-81-9 CF3CF2OCH2CH3 58 AR51-Ethoxy-1,1,2,2,3,3,3-heptafluoropropane 22052-86-4 CF3CF2CF2OCH2CH3 61 AR5HFE–365mcf3 1,1,1,2,2-Pentafluoro-3-methoxypropane378-16-5 CF3CF2CH2OCH3 11 AR4/Table A-1Fluoro(methoxy)methane 460-22-0 CH3OCH2F 13 AR5HFE–263fb2 1,1,1-Trifluoro-2-methoxyethane 460-43-5CF3CH2OCH3 11 AR4/Table A-1R-E-143a; HFE263m11,1,2,2-Tetrafluoro-1-(trifluoromethoxy)ethane 690-22-2 CF3OCH2CH3 29 AR52-Ethoxy-3,3,4,4,5-pentafluorotetrahydro-2,5-bis[1,2,2,2-tetrafluoro-1-(trifluoromethyl)ethyl]-furan920979-28-8 C12H5F19O2 56 AR51-Ethoxy-1,1,2,3,3,3-hexafluoropropane 380-34-7 CF3CHFCF2OCH2CH3 23 AR5HG'-021,1,2,2-Tetrafluoro-1-methoxy-2-(1,1,2,2-tetrafluoro-2-methoxyethoxy)ethane485399-46-0 CH3O(CF2CF2O)2CH3 236 AR5HG'-033,3,4,4,6,6,7,7,9,9,10,10-Dodecafluoro-2,5,8,11-tetraoxadodecane485399-48-2 CH3O(CF2CF2O)3CH3 221 AR5Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRPPage 17Trade NameChemical Designation or Common NameCAS No.Chemical FormulaProposedGWPGWP SourceHFE–374pc2 1-ethoxy-1,1,2,2-tetrafluoroethane 512–51–6 CH3CH2OCF2CHF2 557 AR4/Table A-11,1,2,2-Tetrafluoro-3-methoxy-propane; Methyl 2,2,3,3-tetrafluoropropyl ether60598-17-6 CHF2CF2CH2OCH3 0.5AR5 (Precise GWPCalculated)HG'-01 1,1,2,2-Tetrafluoro-1,2-dimethoxyethane 73287-23-7 CH3OCF2CF2OCH3 222 AR5Fluorinated formatesTrifluoromethyl formate 85358-65-2 HCOOCF3 588 AR5Perfluoroethyl formate 313064-40-3 HCOOCF2CF3 580 AR5Perfluoropropyl formate 271257-42-2 HCOOCF2CF2CF3 376 AR5Perfluorobutyl formate 197218-56-7 HCOOCF2CF2CF2CF3392 AR52,2,2-Trifluoroethyl formate 32042-38-9 HCOOCH2CF333 AR53,3,3-Trifluoropropyl formate 1344118-09-7 HCOOCH2CH2CF3 17 AR51,2,2,2-Tetrafluoroethyl formate 481631-19-0 HCOOCHFCF3 470 AR51,1,1,3,3,3-Hexafluoropropan-2-yl formate 856766-70-6 HCOOCH(CF3)2 333 AR5Fluorinated acetatesPerfluorobutyl acetate 209597-28-4 CH3COOCF2CF2CF2CF3 1.6AR5 (Precise GWPCalculated)Perfluoropropyl acetate 1344118-10-0 CH3COOCF2CF2CF3 1.8AR5 (Precise GWPCalculated)Perfluoroethyl acetate 343269-97-6 CH3COOCF2CF3 2.1AR5 (Precise GWPCalculated)Trifluoromethyl acetate 74123-20-9 CH3COOCF3 2.0AR5 (Precise GWPCalculated)1,1-Difluoroethyl 2,2,2-trifluoroacetate 1344118-13-3 CF3COOCF2CH3 31 AR5Ethyl 2,2,2-trifluoroacetate 383-63-1 CF3COOCH2CH31.30 AR52,2,2-Trifluoroethyl 2,2,2-trifluoroacetate 407-38-5 CF3COOCH2CF3 7 AR5Methyl 2,2-difluoroacetate 433-53-4 HCF2COOCH3 3 AR5Difluoromethyl 2,2,2-trifluoroacetate 2024-86-4 CF3COOCHF2 27 AR5Methyl 2,2,2-trifluoroacetate 431-47-0 CF3COOCH3 52 AR5CarbonofluoridatesMethyl carbonofluoridate 1538-06-3 FCOOCH3 95 AR5Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRPPage 18Trade NameChemical Designation or Common NameCAS No.Chemical FormulaProposedGWPGWP Source1,1-Difluoroethyl carbonofluoridate 1344118-11-1 FCOOCF2CH3 27 AR5Fluorinated alcohols other than fluorotelomer alcohols2,2,3,3,4,4,5,5-Octafluorocyclopentanol 16621-87-7-(CF2)4CH(OH)- 73 AR4/Table A-1Bis(trifluoromethyl)–methanol 920-66-1 (CF3)2CHOH195 AR4/Table A-12,2,3,3,3–pentafluoropropanol 422-05-9 CF3CF2CH2OH42 AR4/Table A-14,4,4-Trifluorobutan-1-ol 461-18-7 CF3(CH2)2CH2OH0.05AR5 (Precise GWPCalculated)2,2,3,3,4,4,4-Heptafluorobutan-1-ol 375-01-9 C3F7CH2OH 25 AR52,2,3,3-Tetrafluoro-1-propanol 76-37-9 CHF2CF2CH2OH 13 AR52,2,3,4,4,4-Hexafluoro-1-butanol 382-31-0 CF3CHFCF2CH2OH 17 AR52-Fluoroethanol 371-62-0 CH2FCH2OH 1.07AR5 (Precise GWPCalculated)2,2-Difluoroethanol 359-13-7 CHF2CH2OH 3 AR52,2,2-Trifluoroethanol 75-89-8 CF3CH2OH 20 AR5Unsaturated PFCsPFC C-1418 Perfluorocyclopentene; Octafluorocyclopentene 559-40-0 c-C5F81.97 AR5Dyneon HFP(3M)hexafluoropropylene (HFP); PFC-1216; Perfluoropropene 116-15-4 C3F6, CF3CF=CF20.05AR5 (Precise GWPCalculated)TFE tetrafluoroethylene (TFE); PFC-1114; Perfluoroethene 116-14-3 CF2=CF2, C2F4;0.004AR5 (Precise GWPCalculated)Perfluorobuta-1,3-diene 685-63-2 CF2=CFCF=CF20.003AR5 (Precise GWPCalculated)Perfluorobut-1-ene 357-26-6 CF3CF2CF=CF20.10AR5 (Precise GWPCalculated)Perfluorobut-2-ene 360-89-4 CF3CF=CFCF31.82AR5 (Precise GWPCalculated)Unsaturated HFCsHFC-1234ze(Z) (Z)-1,3,3,3-Tetrafluoroprop-1-ene 29118-25-0C3H2F4**trans-**CF3CH=CHF,CF3CH=CHF(Z)0.29AR5 (Precise GWPCalculated)Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRPPage 19Trade NameChemical Designation or Common NameCAS No.Chemical FormulaProposedGWPGWP SourceHFC-1234ze(E) (E)-1,3,3,3-Tetrafluoroprop-1-ene 1645-83-6C3H2F4**cis-**CF3CH=CHF0.97AR5 (Precise GWPCalculated)TFPtrifluoro propene (TFP); HFC-1243zf; 3,3,3-Trifluoroprop-1-ene677-21-4 C3H3F3 ,CF3CH=CH20.12AR5 (Precise GWPCalculated)VF vinyl fluoride (VF); HFC-1141 75-02-5 C2H3F, CH2=CHF 0.02AR5 (Precise GWPCalculated)VF2 vinylidiene fluoride (VF2); HFC-1132a 75-38-7 C2H2F2, CF2=CH20.04AR5 (Precise GWPCalculated)HFC-1234yf;HFO-1234yf2,3,3,3-Tetrafluoroprop-1-ene 754-12-1C3H2F4CF3CF=CH20.31AR5 (Precise GWPCalculated)Capstone 42-Uperfluorobutyl ethene (42-U); 3,3,4,4,5,5,6,6,6-Nonafluorohex-1-ene19430-93-4 C6H3F9,CF3(CF2)3CH=CH20.16AR5 (Precise GWPCalculated)Capstone 62-Uperfluorohexyl ethene (62-U); 3,3,4,4,5,5,6,6,7,7,8,8,8-Tridecafluorooct-1-ene25291-17-2 C8H3F13, CF3(CF2)5CH=CH20.11AR5 (Precise GWPCalculated)Capstone 82-Uperfluorooctyl ethene (82-U);3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-Heptadecafluorodec-1-ene21652-58-4C10H3F17,CF3(CF2)7CH=CH20.09AR5 (Precise GWPCalculated)Solstice 1233zd(E)trans-1-chloro-3,3,3-trifluoroprop-1-ene 102687-65-0 C3H2ClF3, CHCl=CHCF31.34AR5 (Precise GWPCalculated)(E)-HFC-1225ye (E)-1,2,3,3,3-Pentafluoroprop-1-ene5595-10-8 CF3CF=CHF(E) 0.06AR5 (Precise GWPCalculated)(Z)-HFC-1225ye (Z)-1,2,3,3,3-Pentafluoroprop-1-ene5528-43-8 CF3CF=CHF(Z) 0.22AR5 (Precise GWPCalculated)HFO-1345zfc 3,3,4,4,4-Pentafluorobut-1-ene 374-27-6C2F5CH=CH20.09AR5 (Precise GWPCalculated)(Z)-HFC-1336 (Z)-1,1,1,4,4,4-Hexafluorobut-2-ene 692-49-9 CF3CH=CHCF3(Z) 1.58AR5 (Precise GWPCalculated)PMVE, HFE-216 perfluoromethyl vinyl ether (PMVE) 1187-93-5 CF3OCF=CF20.17AR5 (Precise GWPCalculated)Fluoroxene (2,2,2-Trifluoroethoxy)ethene 406-90-6 CF3CH2OCH=CH20.05AR5 (Precise GWPCalculated)Fluorinated aldehydes3,3,3-Trifluoro-propanal 460-40-2 CF3CH2CHO 0.01AR5 (Precise GWPCalculated)Revised Analysis of Default GWPs for Fluorinated GHGs Reported Under the GHGRPPage 20Trade NameChemical Designation or Common NameCAS No.Chemical FormulaProposedGWPGWP SourceFluorinated ketonesNovec 1230FK-5-1-12 Perfluoroketone; FK-5-1-12myy2; PERFLUORO(2-METHYL-3-PENTANONE)756-13-8 CF3CF2C(O)CF(CF3)20.1AR5 (Precise GWPCalculated)Fluorotelomer alcohols3,3,3-Trifluoropropan-1-ol 2240-88-2 CF3CH2CH2OH 0.35AR5 (Precise GWPCalculated)3,3,4,4,5,5,6,6,7,7,7-Undecafluoroheptan-1-ol 185689-57-0 CF3(CF2)4CH2CH2OH 0.43 AR53,3,4,4,5,5,6,6,7,7,8,8,9,9,9-Pentadecafluorononan-1-ol 755-02-2 CF3(CF2)6CH2CH2OH 0.33 AR53,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-Nonadecafluoroundecan-1-ol87017-97-8 CF3(CF2)8CH2CH2OH 0.19 AR5Fluorinated GHGs with one or more carbon-iodine bondsTrifluoroiodomethane 2314-97-8 CF3I 0.4 AR4Other fluorinated GHGs and HTFsHalon-1202 Dibromodifluoromethane 75-61-6 CBR2F2231 AR5Halon-2311 /Halothane2-Bromo-2-chloro-1,1,1-trifluoroethane 151-67-7 CHBrClCF341 AR5