A report to the 18th session of the Conference of the Parties to the United Nations Framework Convention on Climate Change. Hydrofluorocarbons (HFCs) are man-made fluorinated gases (F-gases) developed and commercialised to replace CFCs, HCFCs and other chemicals that deplete the ozone layer. Unlike CFCs and HCFCs, HFCs do not destroy ozone; however, they are powerful greenhouse gases (GHGs), with global warming potentials (GWP) hundreds or thousands of times more powerful than carbon dioxide (CO2). HFCs are primarily used in refrigeration, air conditioning, foam blowing, aerosols, fire protection and solvents. Climate-friendly alternative refrigerants and technologies are available, and are being developed, which means that HFCs can be phased out over time.