Chlorofluorocarbons, or CFCs, are man-made chemical compounds that were commonly used in refrigeration, air conditioning, and aerosol sprays. They are composed of chlorine, fluorine, and carbon atoms. CFCs are known for their ability to deplete the ozone layer, which protects the Earth from harmful ultraviolet (UV) radiation. Due to their environmental impact, the production and use of CFCs have been largely phased out under the Montreal Protocol, an international treaty established in 1987. This agreement aimed to reduce substances that harm the ozone layer, leading to a gradual recovery of this vital atmospheric shield.