rofluorocarbons (CFCs) were invented in the 1920s, they are a compound of carbon
             containing chlorine and fluorine. CFCs are man made chemicals, so we call them synthetic
             chemicals. Since their introduction CFCs have been used as: refrigerants in refrigerators and air
             conditioning units, propellants in aerosol cans, foaming agents in the production of packaging,
             cleaners used in the electronics industry, and fire extinguisher chemicals. CFCs are well suited to
             all these applications as they are non-flammable, non-toxic, have high chemical stability
             ...