UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF 

AIR AND RADIATION 

FEB 2 4 2012 

MEMORANDUM 


SUBJECT: Final Determinations Regarding Requests to Use Provisional Global Warming 

Potentials Under the Fluorinated Gas Production Category ofthe Greenhouse Gas 

Reporting Rule 

FROM: 

Office 

Sarah Dunham, 

of Atmospheric 

Director 

Programs 

~ 

TO: Docket EPA-HQ-OAR -2009-0927 

This memorandum finalizes EPA's preliminary determinations regarding requests to use 

provisional global warming potentials (GWPs) for seven fluorinated greenhouse gases (GHGs) 

submitted by DuPont de Nemours, Inc. and Honeywell International for five fluorinated gas 

facilities for purposes ofthe calculations in 40 CFR 98.123(c)(l) (a provision ofsubpart L ofthe 

Greenhouse Gas Reporting rule). The calculations in 40 CFR 98.123(c)(l) are used to determine 

whether a chemical meets the annual emissions threshold requiring a facility to use stack testing 

to establish an emission factor for a continuous process vent. EPA's final determination is that 

the requests for these fluorinated GHGs meet the requirements ofthe rule. 

EPA published its preliminary determinations regarding the provisional GWPs in the Federal 

Register on February 3, 2012 (77 FR 5514). In that notice, EPA summarized the rationale for its 

preliminary approval ofthe seven provisional GWPs and requested comment on the provisional 

GWPs and the data and analysis supporting them. EPA received two comments in response to 

the notice. One commenter supported EPA's determinations regarding the GWPs submitted. The 

other supported EPA's determinations and also recommended that EPA adopt the provisional 

GWPs in all emissions calculations for the seven fluorinated GHGs. The commenter noted that 

this would promote consistency across emission calculations. This commenter also encouraged 

EPA to allow provisional GWPs to be requested for all emission levels offluorinated GHGs, not 

just for emission levels equal to or greater than 10,000 metric tons C02 equivalent (C02e) for the 

vent. 

EPA shares the goal of promoting consistency across the calculations used to estimate C02­

equivalent emissions and supply in the GHG Reporting rule 1

, and EPA has previously stated that 

I In addition to the calculations at 98.123(c)(l), GWPs are used for threshold calculations to detennine rule 

applicability and for reporting total GHG emissions or supply in C02e for each fac ility or supplier. GHGs whose 

GWPs are not listed in Table A-1 are not included in threshold calculations or in the C02e totals reported by 

facilities and suppliers. However, these GHGs are reported in metric tons of chemical. In this way, infonnation on 
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it plans to periodically update Table A-1 of 40 CFR part 98, the rule's compendium of 

established GWPs for GHGs, through notice and comment rulemaking (see, e.g., 74 FR 56348, 

October 30, 2009). EPA will consider the information submitted in support of the provisional 

GWPs being approved in this notice in future updates to Table A-1. However, adding GWPs to 

Table A-1 goes beyond the scope ofthis determination, as does changing the circumstances 

under which provisional GWPs may be requested. As discussed in the February 3 notice, this 

determination carries out a specific flexibility provision of subpart L, permitting the facilities 

whose requests for provisional GWPs are approved to use those provisional GWPs in 

determining whether they may use engineering calculations rather than stack testing to establish 

an emission factor for the affected continuous process vents. Thus, EPA is not amending Table 

A-1 or subpart L through this action. 

Based on the rationale set forth in the February 3 notice and on the commenters' agreement with 

this rationale, EPA is finalizing its preliminary determinations regarding the seven provisional 

GWPs. Consistent with 40 CFR 98.123(c)(1)(vi)(B), EPA is approving the use ofthe 

provisional GWPs for the calculations in 40 CFR 98.123(c)(l) unless and until EPA determines 

that one or more of the provisional GWPs is in error. If this occurs, EPA will provide reasonable 

notice to the facility. 

For one fluorinated GHG submitted by Honeywell, HFC-1234yf, EPA is not evaluating the 

provisional GWP in this action. This is because the calculated emissions of this chemical did not 

meet the threshold requirement of98.123(c)(1)(vi); that is, HFC-1234yfwas emitted in 

quantities that resulted in total calculated annual emissions of less than 1 0,000 mtC02e ( 5 metric 

tons) using the subpart L default GWP of2,000. EPA notes, however, that the provisional GWP 

submitted by Honeywell is the same as the GWP recognized in other EPA final actions (e.g., 

March 29, 2011; 76 FR 17488). EPA will consider this information, as well as the information 

submitted in support ofthe provisional GWPs being approved in this notice, in future updates to 

Table A-1 of40 CFR Part 98. 

Table 1 presents EPA's final determinations. 

Table 1: Provisional Global Warming Potentials for fluorinated greenhouse gases for 

which EPA has made final determinations that all approval criteria have been met for the 

purposes of the calculations in 98.123(c)(l) of subpart L. 

Fluorinated GHG CAS Number Provisional GWP 

HFC-1234ze 29118-24-9 6 

Hexatluoropropylene (HFP) 116-15-4 0.25 

Pertluoromethyl vinyl ether (PMVE) 1187-93-5 3 

emissions and supply is collected so that when GWPs for these GHGs do become available, they can be applied to 

calculate the C02e ofthe chemical emitted or supplied. 
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Fluorinated GHG CAS Number Provisional GWP 

Tetrafluoroethylene (TFE) 11 6-14-3 0.02 

Trifluoro propene (TFP) 677-21-4 3 

Vinyl fluoride (VF) 75-02-5 0.7 

Vinylidine fluoride (VF2) 75-38-7 0.9 

Note that these final determinations are subject to two limitations. The first is that EPA is 

approving the use of these provisional GWPs only for the calculations in 40 CFR 98.123( c )(1 ); 

this action does not add the provisional GWPs to Table A-1 of40 CFR Part 98. Consequently, 

facilities supplying or emitting the GHGs listed in Table 1 must continue to report these GHGs in 

metric tons ofthe GHG rather than in metric tons ofC02e until GWPs for the GHGs are 

included in Table A-1. The second limitation is that EPA is approving the use of the provisional 

GWPs only by the facilities that requested them. As provided by 40 CFR 98.123(c)(1)(v), 

subpart L facilities that do not have an approved request to use a GWP other than 2000 for a 

fluorinated GHG not listed in Table A-1 must use the default value for the calculations in 40 

CFR 98.123(c)(1).