CFCs were widely used in refrigerants, aerosols, and other industrial applications. However, they were found to be extremely damaging to the ozone layer, a protective shield in the Earth's atmosphere that blocks harmful ultraviolet radiation from the sun.
The Montreal Protocol, an international treaty signed in 1987, phased out the production and use of CFCs and other ozone-depleting substances. This has led to a significant recovery in the ozone layer, and scientists predict that it will fully recover by the middle of the century.
