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Climate Benefits of the SNAP Program Status Change Rule

June 2014

Executive Summary

The U.S. Environmental Protection Agency (EPA) is issuing a proposed rule that would change the status

of certain alternatives1 previously found acceptable under the Significant New Alternatives Policy (SNAP)

program. The EPA is proposing to modify the listings from acceptable to unacceptable for certain

hydrofluorocarbons (HFCs) and HFC blends in aerosol, foam blowing, air conditioning and refrigeration

end‐uses where other alternatives are available or potentially available that pose overall lower risk to

human health and the environment. The emission reductions associated with the proposed rule are

estimated to be 31 to 42 million metric tons (i.e., teragrams) of carbon dioxide equivalent (MMTCO2eq)

in 2020, with the most likely point estimate in this range being 38 MMTCO2eq.  

Background

In June 2013, the President announced the Climate Action Plan (CAP) stating that “while no single step

can reverse the effects of climate change, we have a moral obligation to future generations to leave

them a planet that is not polluted and damaged. Through steady, responsible action to cut carbon

pollution, we can protect our children’s health and begin to slow the effects of climate change so

that we leave behind a cleaner, more stable environment.”2 Among the many actions called for, the

CAP outlined a set of measures to address hydrofluorocarbons (HFCs). In the United States, emissions of

HFCs are expected to double from current levels of 1.5 percent of greenhouse gas (GHG) emissions to 3

percent by 2020 and nearly triple by 2030.3

  HFCs are rapidly accumulating in the atmosphere. For

example, the atmospheric concentration of HFC‐134a, the most abundant HFC, has increased by about

10% per year from 2006 to 2012, and the concentrations of HFC‐143a and HFC‐125 rose over 13% and

16% per year, respectively, from 2007 to 2011.4,5  

The President directed the United States to lead through both international diplomacy and domestic

action in addressing HFCs. In particular, he directed the EPA to use its authority through the Significant

New Alternatives Policy (SNAP) Program to “encourage private sector investment in low‐emissions

technology by identifying and approving climate‐friendly chemicals while prohibiting certain uses of the

most harmful chemical alternatives. In addition, the President has directed his administration to

purchase cleaner alternatives to HFCs whenever feasible and transition over time to equipment that

uses safer and more sustainable alternatives.”6

  

                                                            

1 For purposes of this document, the terms “substitutes” and “alternatives” are used interchangeably. 2 The President’s Climate Action Plan, Executive Office of the President, June 2013. Available at

http://www.whitehouse.gov/sites/default/files/image/president27sclimateactionplan.pdf 3 Ibid.

4 Montzka, S.A.: HFCs in the Atmosphere: Concentrations, Emissions and Impacts, ASHRAE/NIST Conference 2012 5 NOAA data at ftp://ftp.cmdl.noaa.gov/hats/hfcs/ 6 The President’s Climate Action Plan, Executive Office of the President, June 2013, page 10. Available at

http://www.whitehouse.gov/sites/default/files/image/president27sclimateactionplan.pdf
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The EPA is both expanding the list of acceptable alternatives to ozone‐depleting substances (ODS) so

that it includes more alternatives that pose less overall risk to the environment and human health, and

also changing the status of certain alternatives from acceptable to unacceptable. The analysis presented

here concerns the EPA’s proposal to modify the listings from acceptable to unacceptable for certain

HFCs and HFC blends in aerosol, foam blowing, air conditioning and refrigeration end‐uses where other

alternatives are available or potentially available that pose less overall risk to human health and the

environment. The agency considers the intersection between the specific HFC or HFC blend and the

particular end‐use. The proposed action does not assert that any specific HFCs are unacceptable across

all sectors and end‐uses, nor that, for any specific sector, no HFCs are acceptable substitutes. The EPA

recognizes that both fluorinated substitutes (e.g., HFCs, hydrofluoroolefins (HFOs)) and non‐fluorinated

substitutes (e.g., hydrocarbons (HCs), carbon dioxide (CO2)) are potentially available. Thus, consistent

with SNAP’s history and Clean Air Act (CAA) Section 612, the EPA is proposing these modifications

considering the intersection among each substitute being considered, the particular end‐use, the SNAP

criteria for evaluation, and the current suite of other available and potentially available substitutes in

each particular end‐use.

Analysis of Climate Benefits

The EPA’s SNAP Program, pursuant to Section 612 of the Clean Air Act, allows the use of a suite of ODS

substitutes that is safer overall for human health and the environment. For each end use, SNAP lists

safer alternatives as acceptable, lists chemicals as unacceptable if there are safer alternatives available,

or lists substitutes as acceptable under specific use conditions. SNAP’s evaluation of the overall safety of

a substitute considers its toxicity, flammability, ozone depletion potential, and global warming potential

(GWP), among other factors. The CAP directs the EPA to use the SNAP Program to encourage private

sector investment in low‐emissions technology by identifying and approving climate‐friendly chemicals

while prohibiting certain uses of the most harmful chemical alternatives. To this end, SNAP’s proposed

Status Change Rule would change the listing of certain alternatives in the foams, commercial

refrigeration, aerosols, and motor vehicle air‐conditioning (MVAC) sectors either from acceptable to

unacceptable or from acceptable to acceptable subject to use conditions. The complete list of proposed

listing changes for each end use can be found in Appendix A.

Methodology

To estimate the climate benefits of the proposed rule, the EPA compared a business‐as‐usual (BAU)

forecast of HFC emissions to those derived under various scenarios conforming to the proposed rule. In

developing both the BAU forecast and the scenarios, the EPA utilized its Vintaging Model,7 an emission

estimation tool used to derive HFC emission inventories for reporting to the Intergovernmental Panel on

Climate Change (IPCC) as part of the United States’ obligations under the United Nations Framework

Convention on Climate Change (UNFCCC).  

The Vintaging Model was developed as a tool for estimating the annual chemical emissions from

industrial sectors that have historically used ODS in their products. Under the terms of The Montreal

Protocol on Substances that Deplete the Ozone Layer and the United States’ CAA Amendments of 1990,

                                                            

7 VM IO file_v4.4_12.16.09_GER_IMAC_Domestic_2013 Options Updare_AR4_11‐21‐13.xlsm
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the domestic use of ODS has been drastically reduced, forcing these industrial sectors to transition to

more ozone‐friendly chemicals. As these industries have moved toward ODS alternatives, including

HFCs, the Vintaging Model has evolved into a tool for estimating the rise in emissions of these

alternatives and the decline of ODS emissions.

The Vintaging Model estimates emissions from five ODS substitute end‐use sectors: air‐conditioning and

refrigeration, foams, aerosols, solvents, and fire‐extinguishing. Within these sectors, there are 60

independently modeled end‐uses. The model requires information on the market growth for each of the

end‐uses, a history of the market transition from ODS to alternatives, and the characteristics of each

end‐use such as market size or charge sizes and loss rates. As ODS are phased out, a percentage of the

market share originally filled by the ODS is allocated to each of its substitutes.

The model, named for its method of tracking the emissions of annual “vintages” of new equipment that

enter into service, is a “bottom‐up” model. It models the emissions of chemicals based on estimates of

the quantity of equipment or products sold, serviced, and retired each year; the amount of the chemical

required to manufacture and/or maintain the equipment; and the amount emitted during specific time

periods. The Vintaging Model makes use of this market information to build an inventory of the in‐use

stocks of the equipment and ODS and ODS substitute(s) in each of the end‐uses. The simulation is

considered to be a BAU baseline case, and it does not incorporate measures to reduce or eliminate the

emissions of these gases other than those currently regulated by U.S. law or otherwise common in the

industry. Emissions are estimated by applying annual leak rates, service emission rates, and disposal

emission rates to each population of equipment. By aggregating the emission output from the different

end‐uses, the model produces estimates of total annual emissions of each chemical.   

The Vintaging Model synthesizes data from a variety of sources, including data from the ODS Tracking

System maintained by the EPA’s Stratospheric Protection Division and information from submissions to

the EPA under the SNAP program. Published sources include documents prepared by the United Nations

Environment Programme (UNEP) Technical Options Committees, reports from the Alternative

Fluorocarbons Environmental Acceptability Study (AFEAS), and conference proceedings from the

International Conferences on Ozone Protection Technologies and Earth Technologies Forums. The EPA

also coordinates extensively with numerous trade associations and individual companies. For example,

the Alliance for Responsible Atmospheric Policy; the Air‐Conditioning, Heating and Refrigeration

Institute; the Association of Home Appliance Manufacturers; the American Automobile Manufacturers

Association; and many of their member companies have provided valuable information over the years.

Because the Vintaging Model follows a bottom‐up approach, scenarios of alternate pathways may be

developed by changing transition timing, chemical(s) chosen, and emission patterns. For example,

because the proposed rule would not allow certain HFCs to be used in certain end‐uses, a scenario can

be run in the Vintaging Model that assumes that a particular end‐use transitions to an alternative that

would remain acceptable. As a specific example, the scenario may assume some or all new supermarket

systems (within the Vintaging Model end‐use “Large Retail Food”) utilize R‐407A or R‐407F rather than

R‐404A, R‐507A and other chemicals which would move to the list of unacceptable substances in that

end‐use. That scenario could vary in timing; for instance, assuming this transition only begins in 2016 or

by assuming it starts earlier with some new supermarkets utilizing R‐407A or R‐407F in 2014, more in
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2015, and all in 2016. Either such transition would be in compliance with the proposed rule. Likewise, a

scenario could assume transition to new low‐GWP refrigerant blends that have been submitted to the

SNAP program and are under evaluation for that end‐use, such as R‐448A.

To analyze the potential emissions reductions of the proposed rule, scenarios were developed to

estimate the rate at which transition away from higher‐GWP HFCs would progress and what would be

used in place of the higher‐GWP HFCs. The analysis includes three scenarios for comparison: the most

likely transition scenario, a higher, more aggressive transition scenario, and a lower, less aggressive

transition scenario. The scenarios differ in their assumptions on transition away from high‐GWP HFCs in

four ways:  

 earlier/later start of transitions,  

 faster/slower rise to saturation,  

 higher/lower saturation level, and  

 higher/lower preference for lower GWPs in end‐uses where the options vary.  

The U.S. emissions of HFCs from each end‐use were estimated for these scenarios and the baseline

scenario (i.e., BAU scenario without the proposed rule) using the EPA’s Vintaging Model, and the total

GWP‐weighted emissions were calculated in MMTCO2eq as shown below in Table 1 and Figure 1.8 The

version of the Vintaging Model used is consistent with previous EPA analyses of non‐CO2 GHG

abatement options.9

Climate Benefits

As shown in Table 1, implementation of the Status Change Rule is estimated to reduce HFC emissions in

2020 by 31 to 42 MMTCO2eq. The most likely point estimate for HFC emissions reductions in this range

is 38 MMTCO2eq.  The most likely transition scenario was developed based on EPA experience in the

sectors and knowledge of the available, SNAP‐acceptable alternatives that are currently being tested

and implemented. The estimates for all three scenarios exclude domestic climate benefits from

transitions in the light‐duty motor vehicles sector because they are accounted for under separate EPA

analysis.10  However, this analysis includes an element for MVAC exports not included in domestic

climate benefits from HFC emission reductions. In 2013, exports made up about 25% of U. S. passenger

car vehicle production and about 19% of light‐duty truck production;11 thus, for this analysis 20% was

assumed as a conservative estimate to calculate the export‐only MVAC emissions reductions.  

                                                            

8 All GWPs used are direct, 100‐year values from IPCC, 2007: 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. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United

Kingdom and New York, NY, USA 9 Global Mitigation of Non‐CO2 Greenhouse Gases: 2010–2030 (EPA Report 430‐R‐13‐011, September 2013) 10 See Chapter 7 of the Regulatory Impact Analysis: Final Rulemaking for 2017‐2025 Light‐Duty Vehicle Greenhouse Gas

Emission Standards and Corporate Average Fuel Economy Standards, EPA‐420‐R‐12‐016, August 2012. 11 U. S. Department of Commerce, Bureau of Economic Analysis Supplemental Estimates: Motor Vehicles

http://www.bea.gov/national/index.htm
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Table 1. HFC Emissions in Baseline and Higher, Most Likely and Lower Transition Scenarios  

Year

2010 2015 2020 2025 2030

(MMTCO2eq)

U. S. Emissions Baseline 150 215 287 378 428

Estimated Emissions from Higher Scenario 150 207 245 300 311

Estimated Emission Reductions from Higher Scenario ‐ 8 42 78 117

Estimated Emissions from Most Likely Scenario 150 208 249 308 322

Estimated Emissions Reductions from Expected Scenario ‐ 7 38 70 106

Estimated Emissions from Lower Scenario 150 212 256 320 340

Estimated Emissions Reductions from Lower Scenario  ‐ 3 31 58 88

The emission reductions for each sector estimated in 2020 of 38 MMTCO2eq using the most likely

transition scenario can be seen in Figure 1 below. The largest emissions reductions are estimated to

come from the commercial refrigeration sector at a little over 30 MMTCO2eq, primarily from the

reduced annual emissions of higher‐GWP refrigerants from new supermarkets that adopt lower‐GWP

options in 2020 and the preceding years. The other emission reduction estimates by sector are from

foams at 5 MMTCO2eq; export only MVACs at 2 MMTCO2eq; and consumer aerosols at 1 MMTCO2eq.  

Figure 1. Emissions Reductions by Sector in 2020 (MMTCO2eq)

By 2020, most of the provisions in the proposed rule would be effective.12 The differences in the three

scenarios in 2020 and other years are significant mostly because of the lag between when alternatives

are introduced in new air conditioners, refrigeration equipment and foams, and when the emission

reductions are realized. With the exception of the aerosols end‐uses, the later and slower transitions in

                                                            

12 The latest date for removing an alternative from the list of acceptable substitutes occurs in the motor vehicle air conditioning

end‐use; however, because that provision affects MY2021 vehicles, much of the transition will occur in 2020 or earlier.
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the lower scenario have not yet accrued emissions reductions by 2020 to the extent of those accrued

under the most likely scenario, which in turn has not yet reached the levels seen in the higher scenario.

Figure 2. HFC Emissions in Higher Transition Scenario, Lower Transition Scenario, and Baseline  

The growth in emissions reductions can be seen in Figure 2. A short period of transition during which the

implementation of lower‐GWP alternatives is increasing is complete in all end uses by 2021. This is

followed by a period of large benefit increases until about 2030 under all three scenarios, due to the

lifetime of the equipment and foams during which the emissions reductions from those end‐uses are

achieved. After about 2030, emissions reductions continue to grow roughly as a percentage of the

growth of these sectors. In these years, the differences in emissions reductions realized under the

various scenarios quickly stabilize. For example, in these later years the reductions from the most likely

scenario relative to the reductions from the lower scenario show approximately a 10 percent difference.

Such differences are due to the differences in the mix of alternatives after transition in the different

scenarios.

Conclusion

The EPA anticipates that 38 MMTCO2eq is the most likely estimate for the climate benefits associated

with avoided emissions for the proposed SNAP Status Change Rule in 2020. Three scenarios the EPA

considered were developed and compared with a business‐as‐usual scenario. If the EPA were to

consider the emissions reductions in 2025 or another later date, the climate benefits would be greater.
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Appendix A: Listing Changes Proposed in the SNAP Status Change Rule,

by End‐Use

AEROSOLS: UNACCEPTABLE SUBSTITUTES

End‐use Substitute Proposed Decision

Propellants HFC‐125 Unacceptable as of January 1, 2016

AEROSOLS: SUBSTITUTES ACCEPTABLE SUBJECT TO USE CONDITIONS

End‐use Substitute Proposed

Decision

Use Conditions

Propellants HFC‐134a   Acceptable

subject to use

conditions

As of January 1, 2016, acceptable only for use in:

 metered dose inhalers for the treatment of asthma and

chronic obstructive pulmonary disease

 cleaning products for removal of grease, flux and other soils

from electrical equipment or electronics

 sprays for aircraft maintenance

 pesticides for use near electrical wires or in aircraft

 mold release agents  

 lubricants and cleaners for spinnerettes for synthetic fabrics

 sprays for removal of dust from photographic negatives,

semiconductor chips, and specimens under electron

microscopes

 document preservation sprays

 wound care sprays

 topical coolant sprays for pain alleviation

products for removing bandage adhesives from skin

Propellants HFC‐227ea Acceptable

subject to use

conditions

As of January 1, 2016, acceptable only for use in metered dose

inhalers for the treatment of asthma and chronic obstructive

pulmonary disease

REFRIGERATION AND AIR CONDITIONING: UNACCEPTABLE SUBSTITUTES

End‐use Substitute Proposed Decision

Retail food refrigeration* (new

and retrofit)

R‐404A, R‐507A Unacceptable as of

January 1, 2016

Retail food refrigeration

(condensing units and

supermarket systems)(new)

HFC‐227ea, R‐407B, R‐421B, R‐422A, R‐422C, R‐

422D, R‐428A, R‐434A

Unacceptable as of

January 1, 2016

Retail food refrigeration

(condensing units and

supermarket systems) (retrofit)

R‐407B, R‐421B, R‐422A, R‐422C, R‐422D, R‐

428A, R‐434A

Unacceptable as of

January 1, 2016

Retail food refrigeration‐ (stand‐

alone units)(new)

FOR12A, FOR12B, HFC‐134a, HFC‐227ea, IKON B,

KDD6, R‐125/290/134a/600a (55.0/1.0/42.5/1.5),

R‐407A, R‐407B, R‐407C, R‐407F, R‐410A, R‐410B,

R‐417A, R‐421A, R‐421B, R‐422A, R‐422B, R‐

422C, R‐422D, R‐424A, R‐426A, R‐428A, R‐434A,

R‐437A, R‐438A, RS‐24 (2002 formulation), RS‐44

(2003 formulation), SP34E, THR‐03

Unacceptable as of

January 1, 2016
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Vending machines (new and

retrofit)

R‐404A, R‐507A Unacceptable as of

January 1, 2016

Vending machines (new) FOR12A, FOR12B, HFC‐134a, IKON B, KDD6, R‐

125/290/134a/600a (55.0/1.0/42.5/1.5), R‐407C,

R‐410A, R‐410B, R‐417A, R‐421A, R‐422B, R‐

422C, R‐422D, R‐426A, R‐437A, R‐438A, RS‐24

(2002 formulation), SP34E

Unacceptable as of

January 1, 2016

Motor vehicle air conditioning

(new equipment in passenger

cars and light‐duty trucks only)

HFC‐134a Unacceptable as of

Model Year (MY) 2021

Motor vehicle air conditioning

(new equipment in passenger

cars and light‐duty trucks only)

R‐426A, SP34E Unacceptable as of

Model Year 2017

*Unless otherwise specified, Retail Food Refrigeration includes supermarket systems, condensing units and stand‐

alone equipment.

FOAM BLOWING AGENTS: UNACCEPTABLE SUBSTITUTES

End‐use Substitute Proposed Decision

Rigid Polyurethane: Appliance HFC‐134a, HFC‐245fa, HFC‐365mfc and

blends thereof; Formacel TI, and

Formacel Z‐6

Unacceptable as of January 1, 2017

Rigid Polyurethane: Spray HFC‐134a and Formacel TI Unacceptable as of January 1, 2017

Rigid Polyurethane:

Commercial Refrigeration and

Sandwich Panels

HFC‐134a, HFC‐245fa, HFC‐365mfc,

and blends thereof; Formacel TI, and

Formacel Z‐6

Unacceptable as of January 1, 2017

Flexible Polyurethane HFC‐134a, HFC‐245fa, HFC‐365mfc,

and blends thereof

Unacceptable as of January 1, 2017

Rigid Polyurethane: Slabstock

and Other

HFC‐134a, HFC‐245fa, HFC‐365mfc and

blends thereof; Formacel TI, and

Formacel Z‐6

Unacceptable as of January 1, 2017

Rigid Polyurethane and

Polyisocyanurate Laminated

Boardstock

HFC‐134a, HFC‐245fa, HFC‐365mfc and

blends thereof  

Unacceptable as of January 1, 2017

Polystyrene: Extruded Sheet HFC‐134a, HFC‐245fa, HFC‐365mfc,

and blends thereof; Formacel TI, and

Formacel Z‐6

Unacceptable as of January 1, 2017

Polystyrene: Extruded

Boardstock and Billet

HFC‐134a, HFC‐245fa, HFC‐365mfc,

and blends thereof; Formacel B, and

Formacel Z‐6

Unacceptable as of January 1, 2017

Integral Skin Polyurethane HFC‐134a, HFC‐245fa, HFC‐365mfc,

and blends thereof; Formacel TI, and

Formacel Z‐6

Unacceptable as of January 1, 2017

Polyolefin HFC‐134a, HFC‐245fa, HFC‐365mfc,

and blends thereof; Formacel TI, and

Formacel Z‐6

Unacceptable as of January 1, 2017

Phenolic Insulation Board and

Bunstock

HFC‐134a, HFC‐143a, HFC‐245fa, HFC‐

365mfc, and blends thereof

Unacceptable as of January 1, 2017