The U.S. Environmental Protection Agency (EPA) has extended the comment period for its proposed rule to permit the use HFO-1234yf as a refrigerant in motor vehicle air conditioners. The proposal issued under the Significant New Alternatives Program (SNAP) would permit the use of 1234yf only on new vehicles. There is considerable interest from the vehicle manufacturers in 1234yf due to the significantly lower global warming potential of the substance over the current refrigerant used on vehicles, R-134a.
EPA's SNAP proposal has received criticism from car companies due to the extensive vehicle modifications that would need to be made to use the new refrigerant due to concerns expressed by EPA regarding flammability. In addition, the SNAP proposal does not, at this point, permit the retrofitting of the current vehicle population, but the agency is accepting comments on this issue. Issues related to use of the new refrigerant by do-it-yourselfers is expected to be addressed by a soon to be issued rulemaking under the Toxic Substances Control Act (TSCA).
The original comment period was Dec. 18, 2009, but the agency determined to extend it until Feb. 1 in response to both a request from AAIA and the Automotive Products Refrigeration Institute (ARPI), and due to the availability of new supporting materials. Information on the proposed rule can be found at
www.regulation.gov under the docket EPA-HQ-OAR-2008-0664.