It was the Chlorofluorocarbons (CFCs) that were used as the primary propellant in aerosol sprays. More commonly known by the brand name Freon. Notice that basically every aerosol can manufactured today has a “CFC Free” badge somewhere. Refrigerant systems also moved away from using actual Freon, and now use alternative refrigerants.

CFCs were actually invented by the same guy who invented leaded gasoline, Thomas Midgley Jr... He is probably the single most environmentally destructive chemical engineer in history.