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.
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:
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.
In order to submit new proposed chemicals, along with general contact and marketing information, for a complete submittal, the EPA requires reports on:
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.