The chemical name for Freon refrigerants is dichlorodifluoromethane, more commonly known as chlorofluorocarbons or CFCs. Following the discovery of the destructive qualities of CFCs on the Earth's environment the use of CFCs has been gradually phased out of use in the U.S. beginning in 1992. To be involved in the purchase of Freon or the maintenance of equipment containing Freon, technicians must be certified by the Environmental Protection Agency.
To become certified as a technician by the EPA an individual must pass a core exam based on the depleting effect of CFCs on the environment and legislation including the Montreal Protocol and the Clean Air Act. Technicians can become certified in maintaining three types of refrigerant containing equipment, which are small appliances, high-pressure and low-pressure. When certified in all three, a technician is "universally certified."
Technicians are only allowed to be involved in maintaining and recycling Freon in the type of appliance they gain certification in. For example, a certified automobile technician cannot service residential air conditioning equipment containing Freon.