Trichlorofluoromethane, commonly known as CFC-11, is a colorless gas that was widely used as a refrigerant and aerosol propellant. It belongs to a group of chemicals called chlorofluorocarbons, which were popular for their effectiveness in cooling systems and as solvents in the manufacturing process. However, the use of trichlorofluoromethane has significantly declined due to its harmful effects on the ozone layer. When released into the atmosphere, it can break down ozone molecules, leading to increased ultraviolet radiation reaching the Earth's surface. This has prompted international agreements, such as the Montreal Protocol, to phase out its production and use.