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: Sarah Dunham, Director

# ~ Office ofAtmospheric 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 stacktesting 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 ontheprovisional 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 justfor emission levels equal to or greater than 10,000 metric tons C02equivalent (C02 e) for the vent. EPA shares the goal ofpromoting 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 facility or supplier
. GHGs whose GWPs are not listed in TableA-1 are not included i n threshold calculations or in the C0 2etotals reported by facilities and suppli ers. However, these GHGs are reported in metric tons ofchemical. In this way, infonnation on

### Page 2 of3 it plans to periodically update Table A-1 of40 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 ofthe 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 ofsubpart 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 ofthe provisional GWPs is in error. Ifthis 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 ofthis 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 ofless 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 CFRPart 98. Table 1presents 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 ofthe calculations in 98.123(c)(l) ofsubpartL.
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.Page 3 of3
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 ofthese 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 CFRPart 98. Consequently, facilities supplying oremitting the GHGs listed in Table 1must 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 ofthe provisional GWPs only bythe 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 otherthan 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).