Hydrofluorocarbon

Hydrofluorocarbons (HFCs) are synthetic organic compounds that contain fluorine and hydrogen atoms, and are the most common type of organofluorine compounds. Most are gases at room temperature and pressure. They are frequently used in air conditioning and as refrigerants; R-134a (1,1,1,2-tetrafluoroethane) is one of the most commonly used HFC refrigerants. In order to aid the recovery of the stratospheric ozone layer, HFCs were adopted to replace the more potent chlorofluorocarbons (CFCs), which were phased out from use by the Montreal Protocol, and hydrochlorofluorocarbons (HCFCs) which are presently being phased out.^[1] HFCs replaced older chlorofluorocarbons such as R-12 and hydrochlorofluorocarbons such as R-21.^[2] HFCs are also used in insulating foams, aerosol propellants, as solvents and for fire protection.

They may not harm the ozone layer as much as the compounds they replace, but they still contribute to global warming --- with some like trifluoromethane having 11,700 times the warming potential of carbon dioxide.^[3] Their atmospheric concentrations and contribution to anthropogenic greenhouse gas emissions are rapidly increasing --- consumption rose from near zero in 1990 to 1.2 billion tons of carbon dioxide equivalent in 2010^[4] --- causing international concern about their radiative forcing.