Comments
CFCs cause narcosis above levels of 500-1000 ppm, levels which may occur when used in a confined space. At high concentrations, CFCs can also cause cardiac sensitization and sudden death. [LaDou, p. 554] Chlorodifluoromethane, dichlorodifluoromethane, fluorotrichloromethane, 1,1,2-trichlorotrifluoroethane, and bromochlorodifluoromethane are listed by the U.N. International Drug Control Programme as ones subject to volatile substance abuse. [http://www.unodc.org] Cases of irritant asthma have been reported after exposure to Halon 1211 (bromochlorodifluoromethane), Halon 1301 (bromotrifluoromethane) used in fire extinguishers, and from heated freons. [Matrat M et al. Reactive airways dysfunction syndrome caused by bromochlorodifluoromethane from fire extinguishers. Occup Environ Med 2004;61:712-714] The high concentrations that cause anesthetic effects can also displace oxygen and cause asphyxia. Some agents are hepatotoxic after absorption of large doses. In the presence of intense heat or flame, CFCs may decompose producing irritant gases such as phosgene, HCL, HF, and carbonyl fluoride. [Olson, p. 251] CFCs are heavier than air and accumulate in low-lying areas. [HSDB]