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. When CFCs are released into the atmosphere, they eventually reach the stratosphere, where ultraviolet light breaks them down, releasing chlorine atoms. These chlorine atoms can destroy thousands of ozone molecules, leading to increased UV radiation reaching the Earth's surface. Due to their environmental impact, the production of CFCs has been largely phased out under the Montreal Protocol.