Chlorofluorocarbons (CFCs) are man-made chemical compounds that contain chlorine, fluorine, and carbon. They were commonly used in refrigeration, air conditioning, and aerosol propellants due to their stability and non-flammability. However, CFCs are harmful to the environment because they can deplete the ozone layer, which protects the Earth from harmful ultraviolet (UV) radiation. The use of CFCs has been largely phased out since the 1980s, following the discovery of their damaging effects on the ozone layer. International agreements, such as the Montreal Protocol, have successfully reduced CFC production and consumption, leading to gradual recovery of the ozone layer.