The physical, chemical, and toxicological properties of perfluorocarbons (PFCs), chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and bromo- or iodofluorinated derivatives are reviewed. The principal methods for their manufacture, including cobalt trifluoride or electrochemical fluorinations, and liquid- or vapor-phase additions and halogen exchanges with hydrofluoric acid are discussed. The diverse commercial uses of fluorinated aliphatics are described with particular emphasis on the primary high volume markets for refrigerants, foam-blowing agents, propellants, and cleaning agents. The ozone-depleting potentials of chlorodifluoromethane (HCFC-22) and the CFCs traditionally used in these markets including fluorotrichloromethane (CFC-11), dichlorodifluoromethane (CFC-12), 1,1,2-trichlorotrifluoromethane (CFC-113), 1,2-dichlorotetrafluoroethane (CFC-114), and chloropentafluoroethane (CFC-115), and those of the principal brominated materials used as fire extinguishants, bromotrifluoromethane (H-13B1) and bromochlorodifluoromethane (H-12B1), are discussed. The impact of the Montreal Protocol on internationally regulating the manufacture of ozone-depleting materials, especially CFCs, and the industry's progress in developing suitable replacements are reviewed. The properties of the CFCs are compared to those of their leading replacement candidates including 1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoroethane (HFC-125), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123), 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124), 1,1-dichloro-1-fluoroethane (HCFC-141b), 1-chloro-1,1-difluoroethane (HCFC-142b), 1,1-dichloro-2,2,3,3,3-penta- fluoropropane (HCFC-225ca), and 1,3-dichloro-1,1,2,2,3-pentafluoropropane (HCFC-225cb).