Climate Benefits of the SNAP Program 

Status Change Rule

April 2015

U.S. Environmental Protection Agency

Stratospheric Protection Division

Office of Atmospheric Programs

Office of Air and Radiation

1
Climate Benefits of the SNAP Program Status Change Rule

April 2015

Executive Summary

The U.S. Environmental Protection Agency (EPA) is issuing a final rule that changes the status of certain 

alternatives0F

1 previously found acceptable under the Significant New Alternatives Policy (SNAP) program. 

The EPA is modifying 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 emissions avoided associated with the final rule are estimated to be 28 to 36 million 

metric tons (i.e., teragrams) of carbon dioxide equivalent (MMTCO2eq) in 2020, with the most likely point 

estimate in this range being 34 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.”1F

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 2030.2F

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 2011.3F

4,

4 F

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.”5F

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

2

 
Under the authority of section 612 of the Clean Air Act, the EPA is both expanding the list of acceptable 

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

analysis presented here concerns the EPA’s final action 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. In this action, the EPA is not listing any specific HFCs

as unacceptable across all sectors and end-uses, nor is the EPA determining, for any specific sector, that 

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 Clean Air Act (CAA) Section 612, the existing SNAP 

regulations, and historical practice under the SNAP program, the EPA has considered the intersection 

among each substitute being evaluated, 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, evaluates whether substitutes are

safer overall for human health and the environment than other available substitutes. For each end use, 

SNAP lists substitutes as either acceptable, acceptable subject to use conditions, acceptable subject to 

narrowed use limits, or unacceptable. 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 lowemissions technology by identifying and approving climate-friendly chemicals while prohibiting certain 

uses of the most harmful chemical alternatives. To this end, SNAP’s Status Change Rule changes the 

listing of certain alternatives in the foams, commercial refrigeration, aerosols, and motor vehicle airconditioning (MVAC) sectors from acceptable to unacceptable, from acceptable to acceptable subject to 

use conditions, or from acceptable to acceptable subject to narrowed use limits. The specific listing 

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

Methodology

To estimate the climate benefits of the rule, the EPA compared a business-as-usual (BAU) forecast of HFC 

emissions with those derived under various scenarios conforming to the rule. In developing both the BAU 

forecast and the scenarios, the EPA utilized its Vintaging Model,6F

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). 

7 VM IO file_v4.4_12.16.09_GER_IMAC_Domestic_2013 Options Update_AR4_11-21-13.xlsm

3

 
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 Clean Air Act, the production and import of 

ODS have been greatly reduced, motivating 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 and ODS-substitute end-use sectors: airconditioning 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 ODS and ODS substitutes 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 required by statute or regulation, 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 final rule does 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 

4
(within the Vintaging Model end-use “Large Retail Food”) utilize R-407A or R-407F rather than R-404A, R507A and other chemicals which are being listed as unacceptable in that end-use. That scenario could 

vary in timing; for instance, by assuming this transition only begins in 2017 or by assuming it starts 

earlier, with some new supermarkets utilizing R-407A or R-407F in 2015 and the rest in 2016. Either such 

transition would be in compliance with the final rule assuming the transition is complete by the required 

date. 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 final 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.7F

8

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 analyzed 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 rule) using the EPA’s Vintaging Model, and the total GWPweighted emissions were calculated in MMTCO2eq as shown below in Table 1 and Figure 1.8F

9 The version 

of the Vintaging Model used is consistent with previous EPA analyses of non-CO2 GHG abatement 

options.9F

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Climate Benefits

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

in 2020 by 28 to 36 MMTCO2eq. The most likely point estimate for net HFC emissions reductions in this 

range is 34 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 

8 The scenarios analyzed here reflect possible transitions for compliance based on considerations of the market and 

activity towards lower-GWP solutions. A separate technical support document analyzes the cost of complying with 

the final rule using a different transition scenario that looks at the lower-cost options of available technologies. 

Higher or lower climate benefits do not necessarily correlate to higher or lower costs due to the different 

assumptions and methodologies used in the different analyses. However, the transitions assumed in the lower, less 

aggressive scenario here are similar to the transitions assumed in the cost analysis. 9 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. Where GWPs are not available from that source, values are taken from the literature as 

referenced in the SNAP decisions first listing such substances as acceptable.

10 Global Mitigation of Non-CO2 Greenhouse Gases: 2010–2030 (EPA Report 430-R-13-011, September 2013)

5

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

analysis.10F

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

climate benefits under that separate analysis. In 2013, exports made up about 25% of U. S. passenger car

vehicle production and about 19% of light-duty truck production;11F

12 thus, for this analysis 20% was 

assumed as a conservative estimate to calculate the export-only MVAC emissions reductions. Of the 20% 

export segment, 48% were considered for benefits of this rule because 52% of U.S. exports in 2013 were 

to countries that either have policies in place or under consideration that would prohibit the use of HFC134a in light-duty vehicle air conditioning either at the same time as this rule or before MY 2021. Also, to 

reflect the narrowed use provisions in the final rule for exports of MVAC systems to countries lacking 

infrastructure to service systems with certain alternative refrigerants, the rate of market penetration was 

adjusted in the scenarios run within the Vintaging Model.

Table 1. Emissions Profile of Affected Sectors/Applications in Transition Scenarios and Baseline

Year

2010 2015 2020 2025 2030

(MMTCO2eq)

U. S. Emissions Baseline 150 215 287 378 428

Estimated Emissions from Higher Scenario 150 210 251 308 320

Estimated Emission Reductions from Higher Scenario - 5 36 70 108

Estimated Emissions from Most Likely Scenario 150 211 254 314 330

Estimated Emissions Reductions from Most Likely Scenario - 4 34 64 98

Estimated Emissions from Lower Scenario 150 212 259 325 347

Estimated Emissions Reductions from Lower Scenario - 3 28 53 81

The estimated emission reductions in 2020 of 34 MMTCO2eq for all sectors 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 approximately 28 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 1 MMTCO2eq; and consumer aerosols at 0.5 MMTCO2eq.

11 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. 12 U. S. Department of Commerce, Bureau of Economic Analysis Supplemental Estimates: Motor Vehicles 

http://www.bea.gov/national/index.htm

6

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

By 2020, most of the provisions in the final rule will be in effect.12F

13 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 motor vehicle 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 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.

13 The latest date for changing the status of an alternative 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.

7

 
Figure 2. Emissions Profile of Affected Sectors/Applications in Transition Scenarios 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 34 MMTCO2eq is the most likely estimate for the climate benefits associated 

with avoided emissions for the 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 in the SNAP Status Change Rule by End Use

Sector Description of Regulatory Change

MVACs List unacceptable HFC-134a for new MVACs starting in model year 2021 except 

as allowed under a narrowed use limit for certain exports.

Aerosols List unacceptable HFC-125 for aerosols in 2016, restrict use of HFC-134a and 

blends of HFC-134a to certain medical aerosols and technical aerosols in 2016; 

restrict HFC-227ea and blends of HFC-227ea and HFC-134a in aerosols to 

metered dose inhalers in 2016.

Foams List unacceptable HFC-134a, HFC-245fa, HFC-365mfc, and blends thereof, 

Formacel TI, and Formacel Z-6 in rigid polyurethane (PU) appliance foam, rigid 

PU commercial refrigeration and sandwich panels, polyolefin, and PU marine 

floatation foam in 2020.

List unacceptable HFC-134a, HFC-245fa, HFC-365mfc, and blends thereof;

Formacel TI, and Formacel Z-6 in rigid PU slabstock and other in 2019.

List unacceptable HFC-134a, HFC-245fa, HFC-365mfc, and blends thereof; in 

rigid PU and polyisocyanurate laminated boardstock and in flexible PU in 2017.

List unacceptable HFC-134a, HFC-245fa, HFC-365mfc, and blends thereof;

Formacel TI, and Formacel Z-6 in integral skin PU and in polystyrene extruded 

sheet in 2017.

List unacceptable HFC-134a, HFC-245fa, HFC-365mfc, and blends thereof;

Formacel B, Formacel TI, and Formacel Z-6 in integral skin PU and in 

polystyrene extruded boardstock and billet (XPS) in 2020.

List unacceptable HFC-143a, HFC-134a, HFC-245fa, HFC-365mfc, and blends 

thereof; in phenolic insulation board and bunstock in 2017.

Commercial 

Refrigeration

List unacceptable 10 high-GWP HFCs/HFC blends (R-404A, R-407B, R-421B, R422A, R-422C, R-422D, R-428A, R-434A, R-507A, and R-227ea) for new 

supermarket systems in 2017.

List unacceptable 9 high-GWP HFCs/HFC blends (R-404A, R-407B, R-421B, R422A, R-422C, R-422D, R-428A, R-434A, and R-507A,) for retrofitted 

supermarket systems in 2016.

List unacceptable 10 high-GWP HFCs/HFC blends (R-404A, R-407B, R-421B, R422A, R-422C, R-422D, R-428A, R-434A, R-507A, and R-227ea) for new remote 

condensing units in 2018.

List unacceptable 9 high-GWP HFCs/HFC blends (R-404A, R-407B, R-421B, R422A, R-422C, R-422D, R-428A, R-434A, and R-507A, and R-227ea) for 

retrofitted remote condensing units in 2016.

List unacceptable 20 high-GWP HFCs/HFC blends (FOR12A, FOR12B, HFC-134a, 

KDD6, R-125/290/134a/600a (55/1/42.5/1.5), R-404A, R-407C, R-410A, R-410B, 

R-417A, R-421A, R-422B, R-422C, R-422D, R-426A, R-437A, R-438A, R-507A, RS24 (2002 formulation), and SP34E) for new vending machines in 2018.

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Sector Description of Regulatory Change

Commercial 

Refrigeration

List unacceptable R-404A and R-507A for retrofitted vending machines in 2016.

List unacceptable 31 high-GWP HFCs/HFC blends (FOR12A, FOR12B, HFC-134a, 

HFC-227ea, KDD6, R-125/290/134a/600a (55/1/42.5/1.5), R-404A, R-407A, R407B, R-407C, R-407F, R-410A, R-410B, R-417A, R-421A, R-421B, R-422A, R422B, R-422C, R-422D, R-424A, R-426A, R-428A, R-434A, R-437A, R-438A, R507A, RS-24 (2002 formulation), RS-44 (2003 formulation), SP34E, and THR-03) 

for new stand-alone medium-temperature units with a compressor capacity 

below 2,200 Btu/hr and not containing a flooded evaporator in 2019.

List unacceptable 28 high-GWP HFCs/HFC blends (HFC-134a, HFC-227ea, KDD6, 

R-125/290/134a/600a (55/1/42.5/1.5), R-404A, R-407A, R-407B, R-407C, R407F, R-410A, R-410B, R-417A, R-421A, R-421B, R-422A, R-422B, R-422C, R422D, R-424A, R-426A, R-428A, R-434A, R-437A, R-438A, R-507A, RS-24 (2002 

formulation), RS-44 (2003 formulation), and SP34E) for new stand-alone 

medium-temperature units with a compressor capacity equal to or greater 

than 2,200 Btu/hr, for new stand-alone units containing a flooded evaporator, 

and for new stand-alone low-temperature units in 2020. 

List unacceptable R-404A and R-507A for retrofitted stand-alone retail food 

refrigeration equipment in 2016.

10