USEPA Issues Final Rule Under Section 612 of Clean Air Act Approving Five Refrigerants as Acceptable for Several End Uses
On February 3, 2015, United States Environmental Protection Agency (USEPA) signed a final rule written under Section 612 of the Clean Air Act for publication in the Federal Register approving five flammable refrigerants substitutes, difluoromethane (also known as hydrofluorocarbon- (HFC)-32) and four hydrocarbons—ethane, isobutane, propane, and the hydrocarbon blend R-441A—as acceptable for several end uses. These alternatives have been approved only for the following specific end uses:
- Ethane in very low temperature refrigeration and in nonmechanical 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
- R-441A in retail food refrigeration (stand-alone commercial refrigerators and freezers), in vending machines, and in room air conditioning units
- HFC-32 in room air conditioning units.
Section 612 of the Clean Air Act authorized the USEPA to develop its Significant New Alternatives Policy (SNAP) program. SNAP was originally intended to expedite replacement of refrigerants that, when released into the ambient air, damage the protective ozone layer in the Earth’s stratosphere with progressively less detrimental alternatives.
The USEPA notes that the use of high global warming potential (GWP) hydrofluorocarbons (HFC) —one type of SNAP alternative—has been increasing in recent years because they are the primary substitutes for ozone-depleting substances, especially in many of the largest end use applications. Accordingly, the USEPA has been using the SNAP program to approve alternatives that do not deplete stratospheric ozone and also have low or lower GWPs than most HFCs. This approach is in line with President Obama’s Climate Action Plan.
According to USEPA, with the exception of HFC-32, the approved alternative hydrocarbons all have GWPs of less than 10 and can be used to replace HFCs with GWPs ranging from 1,430 to 3,920 for the same end uses. USEPA considers HFC-32 to be low-GWP HFC with a GWP of 675, but will not exempt HFC-32 from the prohibition on venting, release, and disposal as it has with the four hydrocarbon refrigerant substitutes, which were deemed not to pose a threat to the environment.