The Significant New Alternatives Policy (also known as Section 612 of the Clean Air Act or SNAP, promulgated at 40 CFR part 82 Subpart G) is a program of the EPA to determine acceptable chemical substitutes, and establish which are prohibited or regulated by the EPA. It also establishes a program by which new alternatives may be accepted, and promulgates timelines to the industry regarding phase-outs of substitutes.

Scope

Originally, Section 612 was limited by ozone-depleting chemicals. However, after passing regulations to phase-out R134a, an HFC refrigerant with no ozone-depleting potential, this phase-out was defended by a subsidiary of DuPont siding with the EPA as it was challenged by a major manufacturer of R134a, and was struck down in 2017. This decision was upheld in 2018. In 2021, a new law was passed as part of the appropriations bill extending the EPA's scope to substances with high GWP as well.

The EPA looks at available chemical substitutes in the following industrial sectors: Adhesives, Coatings, and Inks Aerosols Cleaning Solvents Fire Suppression and Explosion Protection Foam Blowing Agents Refrigeration and Air Conditioning Sterilants Tobacco Expansion

Evaluations are ongoing as technological understanding improves, and can only prohibit substance where the EPA has determined other available substitutes that pose less overall risk to human health and the environment.

Submittal process

In order to submit new proposed chemicals, along with general contact and marketing information, for a complete submittal, the EPA requires reports on: Impurities Byproducts Degradation Products Test Marketing Physical Properties including: molecular weight physical state melting point boiling point specific gravity If a blend bubble point dew point If flammable lower flammability limit upper flammability limit flash point Ozone Depletion Potential (ODP) Global Warming Potential (GWP) VOC content Proposed cost Toxicity Limits Permissible Exposure Limits (PELs) Short-Term Exposure Limits (STELs) Threshold Limit Values (TLVs) Recommended Exposure Limits (RELs) Workplace Environmental Exposure Limits (WEELs) acceptable exposure limits (AELs) Toxicological studies SDS Environmental/Health and Safety Law Review Industry/Application-specific Use Profile

Refrigerants

One important, changing aspect of SNAP is its effect on the HVAC industry. Particularly because it decides which refrigerants may be legally used, it coordinates refrigerant phaseouts in the U.S., and which are prohibited against venting in concordance with Section 608. The following is a list of accepted refrigerants, or phase-out periods according to the EPA.

MVAC Passenger Air Conditioning in Vehicles MVAC Passenger Air Conditioning in Buses and Trains Centrifugal Chillers Positive Displacement Chillers Industrial Process Refrigeration Cold Storage Warehouse Commercial Ice Machines Household Refrigerators and Freezers Ice Skating Rinks Industrial Process Air Conditioning Residential and Light Commercial Air Conditioning and Heat Pumps Residential Dehumidifiers Refrigerated Transport Stand Alone Equipment Refrigerated Food Processing and Dispensing Equipment Remote Condensing Units Typical Supermarket Systems Vending machines Very Low Temperature Refrigeration Water Coolers Ammonia / Water Absorption Ammonia Absorption Ammonia Vapor Compression Ammonia Vapor Compression with Secondary Loop Chlorine Cryogenic Transport Refrigeration System Desiccant Cooling Direct Nitrogen Expansion Evaporative Cooling FOR12A FOR12B Freeze 12 G2018C GHG-HP GHG-X5 HC Blend A HC Blend B HCFC-123 HCFC-124 HCFC-22 HCFC-22/HCFC-142b HCFO-1233zd(E) HFC-134a HFC-134a/HBr (92/8) HFC-152a HFC-227ea HFC-23 HFC-32 HFC-236fa HFC-245fa HFE-347mcc3 (heptafluoropropyl methyl ether) HFE-449s1 (methoxynonafluorobutane, iso and normal) HFE-569sf2 (ethoxynonafluorobutane, iso and normal) HFO-1234ze HFO-1336mzz(Z) ((Z)-1,1,1,4,4,4-hexafluorobut-2-ene) HFO-1336mzz(Z)/dichloroethylene blend (R-514A) Ikon A Ikon B ISCEON 89 NARM-502 Pressure stepdown R-1224yd(Z) R-125/R-134a/R-600a (28.1/70.0/1.9) R-125/R-290/R-134a/R-600a (55.0/1.0/42.5/1.5) R-170 (Ethane) R-1270 (Propylene) R-290 (Propane) R-401A R-401B R-402A R-402B R-403B R-404A R-406A R-407A R-407B R-407C R-407D R-407F R-407H R-408A R-409A R-410A R-410B R-411A R-411B R-414A R-414B R-416A R-417A R-417C R-420A R-421A R-421B R-422A R-422B R-422C R-422D R-423A R-424A R-426A R-427A R-428A R-434A R-437A R-438A R-441A R-442A R-443A R-448A R-449A R-449B R-450A R-452A R-452B R-452C R-453A R-454A R-454B R-454C R-457A R-458A R-507, R-507A R-508A R-508B R-513A R-515B R-600 (Butane) R-744 (Carbon Dioxide, CO2) RB-276 RS-24 (2002 formulation) RS-44 (2003 formulation) Self-chilling cans using CO2 SP34E Stirling Cycle THR-01 THR-02 THR-03 THR-04 Trans-1-chloro-3,3,3-trifluoroprop-1-ene Water / Lithium Bromide Absorption

See also ASHRAE - Standards 15 and 34 are necessary part of most submittal processes to the program Clean Air Act - The act that established section 612 EPA - The central regulatory agency in charge of operating the SNAP program Section 608 - Which helps enforce the chemicals listed as part of the program Title 40 of the Code of Federal Regulations

References

External links CFR section promulgating up-to-date provisions for Section 612 EPA SNAP Website