USEPA has approved hydrocarbon based refrigerants as substitutes for HCFC's CFC's and perfluorocarbons.Environment News service presents a nice overview of EPA's decision in their coverage:
WASHINGTON, DC, December 14, 2011 (ENS) - The U.S. Environmental Protection Agency today issued a rule making greener refrigeration gases legal in household refrigerators and some commercial freezers.The agency added three hydrocarbons as acceptable alternatives in household and small commercial refrigerators and freezers through EPA's Significant New Alternatives Policy program, SNAP, which evaluates substitute chemicals and technologies for ozone-depleting substances under the Clean Air Act.
The new rule legalizes the hydrocarbons propane, isobutane, and a chemical known as R-441A as refrigerants.
Hidden benefits.
Iso-butane and propane (byproducts of oil refining) individually or in blends have a far greater heat exchange capacity than than any halogenated refrigerant. Hence, appliance designers specifying hydrocarbon refrigerants can utilize smaller compressors and heat exchangers, a lower volume of refrigerant, and thus achieve lower energy consumption, shaving weight, space, and cost. With less energy needed to get the compressor chugging, consumer electric bills go down.
Read more:
http://www.treehugger.com/green-home/great-news-usepa-approves-hydrocarbon-refrigerants.html