Significant New Alternatives Policy

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.