Freon's DuPont's trade name for its odorless, colorless, nonflammable, and noncorrosive chlorofluorocarbon and hydrochlorofluorocarbon refrigerants, which are used in air conditioning, refrigeration, and some automatic fire-fighting systems. It's one of a class of chemicals called Haloalkanes; Freon and similar refrigerants have been controversial due to environmental and safety concerns. Inhalation of relatively low concentrations of Freon's unlikely to cause major health problems, but higher c… (More on Freon)