Under the authority of the Clean Air Act, the agency’s Significant New Alternatives Policy (SNAP) program evaluates substitute chemicals and technologies that are safe for the ozone layer.
The new final rule, announced yesterday, expands the list of SNAP-approved substitutes to include more low-global warming potential (GWP) alternatives that can replace both the ozone-depleting substances and high-GWP hydrofluorocarbons (HFCs). The approved substitutes have GWPs that range from 3 to 675 and can replace older compounds with GWPs between 1,400 to 4,000.
The additional low-GWP hydrocarbon refrigerants, subject to use conditions, are approved for use in the following refrigeration and air conditioning applications:
- Ethane in very low temperature refrigeration and in non-mechanical heat transfer;
- Isobutane in retail food refrigeration (stand-alone commercial refrigerators and freezers) and in vending machines;
- Propane in household refrigerators, freezers, or combination refrigerators and freezers, in vending machines, and in room air conditioning units;
- The hydrocarbon blend R-441A in retail food refrigeration (stand-alone commercial refrigerators and freezers), in vending machines and in room air conditioning units; and
- HFC-32 (difluoromethane) in room air conditioning units. HFC-32 has one-third the GWP of the conventional refrigerants currently being used in room air conditioning units.
These refrigerants are already in use in many of these applications in Europe and Asia, the EPA says.
In addition to adding these climate-friendly alternatives, the agency is also exempting all of these substances, except HFC-32, from the Clean Air Act venting prohibition, as current evidence suggests that their venting, release, or disposal does not pose a threat to the environment.
Honeywell last month launched four new lower GWP products for applications ranging from supermarket refrigeration to industrial cooling.