cfc free sign - freon, aerosol inhaler component

chlorofluorocarbon cfcs cfc hydrochlorofluorocarbons halogenated paraffin hydrocarbon carbon hydrogen chlorine fluorine volatile derivative methane ethane propane freon refrigerant propellant aerosol solvent ozone depletion atmosphere manufacture product destructive effect layer air research hazardous environment danger no sign stop symbol warning ban prohibition icon isolated control component composition