Hydrofluorocarbons or HFCs
Hydrofluorocarbons (HFCs) do not contain ozone-destroying chlorine or bromine atoms and are therefore used as substitutes for ozone-depleting compounds such as chlorofluorocarbons (CFCs) in such uses as refrigeration, air conditioning, and the manufacture of insulating foams. Though the HFCs do not deplete the ozone layer, they are potent greenhouse gases. Molecule for molecule, all HFCs are more potent warming agents than carbon dioxide, some are thousands of times more potent. HFCs are in the basket of gases regulated under the 1997 Kyoto Protocol, an international treaty to reduce emissions of greenhouse gases.