Introduced to the world as DuPont’s trade name for its odorless, colorless, nonflammable and noncorrosive chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants, Freon (in this case dichlorodifluoromethane) was developed by two General Motors scientists working for GM’s Frigidaire subsidiary and manufactured by DuPont at Deepwater, N.J., beginning in 1930. These substances initially were developed in the early 20th century as an alternative to the toxic gases that were used as refrigerants such as ammonia, chloromethane and sulfur dioxide. Freon products were produced and marketed through a joint DuPont-GM venture called Kinetic Chemicals Co., up to 1949, when the operations came under control of DuPont’ organic chemicals department.

DuPont began to phase out its production of Freon CFCs in the 1980s after federal regulatory agencies banned their use. The interim replacements for CFCs are HCFCs, which contain chlorine that depletes stratospheric ozone but to a much lesser extent than CFCs. Ultimately, hydrofluorocarbons (HFCs) will replace HCFCs with essentially no ozone destruction, yet they are classed as greenhouse gases.

Any of these gases that are used as refrigerants are designated by an “R-” number. Today, the refrigerants are colloquially known as “Freon,” whether they are made by DuPont or another supplier, as the term has become a genericized trademark.

Source: DuPont, For a list of U.S. EPA-approved replacements for CFC and HCFC refrigerants, visit