The Antarctic ozone hole was discovered in 1985, when scientists observed a severe depletion in Earth's protective layer of stratospheric ozone. Industrial chemicals known as chlorofluorocarbons (CFCs), then widely used as refrigerants, propellants, foam-blowing agents and solvents, were at the root of the ozone depletion. After a concerted global effort to phase out the use of CFCs, ozone today is recovering, especially in the Antarctic.