Chlorofluorocarbons

The completely halogenated chlorofluorocarbons (CFCs) have easily been the most important organic fluorine chemicals produced in the world during the past 60 years. Selected for development by Midgley and his co-workers in the late 1920s, CFC-12* (CF₂CI₂) was considered to be the ideal refrigerant to replace sulfur dioxide and ammonia.1, 2 The low toxicity, nonflammability, and stability of CFC-12 quickly led to the search for other CFCs. Kinetic Chemicals, a joint venture between Du Pont and General Motors, was formed to manufacture the new materials, and later it became part of the Freon Division of Du Pont. As the list of available compounds grew, new application areas emerged such as aerosol propellants, foam blowing agents, and solvents. By the early 1970s, when they were first linked to the destruction of the ozone layer, CFCs were being produced in many countries around the world. Some major producers and their trade names are listed in Table 1.