Hydrofluorocarbons, or HFCs, are a group of synthetic compounds primarily used as refrigerants in air conditioning and refrigeration systems. They are composed of hydrogen, fluorine, and carbon atoms, and are known for their ability to efficiently transfer heat. HFCs were introduced as a replacement for ozone-depleting substances like chlorofluorocarbons (CFCs). While HFCs do not harm the ozone layer, they are potent greenhouse gases that contribute to global warming. Their global warming potential can be thousands of times greater than that of carbon dioxide. As a result, many countries are working to phase out HFCs under international agreements like the Montreal Protocol.