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Emergency and Continuous Exposure Limits for Selected Airborne Contaminants: Volume 2 FLUOROCARBON 114 BACKGROUND INFORMATION PHYSICAL AND CHEMICAL PROPERTIES Chemical formula: CF4CCl2 Molecular weight: 170.93 Chemical name: 1,2-Dichloro-1,1,2,2-tetrafluoroethane Synonyms: FC-114, cryofluorane, Freon 114 CAS number: 76–14–2 Melting point: −94°C Boiling point: 3.8°C Specific gravity of liquid: 1.5312 (0°C) Vapor pressure: 1444 mm Hg (20°C) Solubility: Soluble in alcohol, ether, and water (0.01%) General characteristics: Colorless, noncorrosive, nonflammable gas Conversion factors: 1 ppm=7 mg/m3 1 mg/m3=0.14 ppm OCCURRENCE AND USE 1,2-Dichloro-1,1,2,2-tetrafluoroethane (FC-114) has been used primarily as an aerosol propellant and refrigerant. Air conditioning is a suspected source of FC-114 contamination in submarines. SUMMARY OF TOXICITY DATA EFFECTS ON HUMANS Human exposures to FC-114 at up to 20,000 ppm have shown it to be poorly absorbed and rapidly excreted. Warning signs of overexposure are dizziness, headache, and a tingling sensation (Dollery et al., 1970; Morgan et al., 1972a, b; Paulet, 1970; Paulet and Desbrousses, 1969; Paulet et al., 1969). EFFECTS ON ANIMALS FC-114 has not shown appreciable oral toxicity in laboratory animals in either acute or subchronic studies (Griffith and Sherman, 1969; Haskell Laboratory, 1955a; Quevauviller, 1965; Sherman, 1972). Administration of a foam propelled by FC-114 or of the gas itself to the skin or eyes of guinea pigs and rabbits has resulted in only mild transient irritation (Haskell Laboratory, 1955b; Hood, 1967; Quevauviller et al., 1964).
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Emergency and Continuous Exposure Limits for Selected Airborne Contaminants: Volume 2 Underwriters’ Laboratories, Inc., (1933) has placed FC-114 in Category 6 of its classification of life hazards. This category contains the least toxic gases and vapors; i.e., they do not appear to produce injury or death in test animals as a result of exposures at 200,000 ppm for about 2 h. The lethal concentration of FC-114 for rats in a 2-h exposure is greater than 600,000 ppm, and for guinea pigs, greater than 500,000 ppm (Scholz, 1962). The LC50 in mice exposed for 30 min is 700,000 ppm (Paulet and Desbrousses, 1969). A dog survived an 8-h exposure at 200,000 ppm, but a 16-h exposure was lethal to another dog (Yant et al., 1932). Exposure of dogs at 150,000 ppm for 24 h was not lethal and resulted only in a loss of appetite (Yant et al., 1932). Exposure at 200,000 ppm caused pupillary dilation, convulsions, opisthotonus, and unconsciousness in dogs. However, exposure at 400,000–600,000 ppm was necessary to cause mild CNS effects in rats and guinea pigs. Recovery was rapid and complete in all species. FC-114, like other chlorofluorocarbons and hydrocarbons, is capable of sensitizing the beagle heart to exogenous epinephrine in standard 5-min cardiac-sensitization screening studies. The concentration needed to elicit marked responses in 50% of a group of beagles is 45,000 ppm (Reinhardt et al., 1971). However, dogs exposed to FC-114 while running on a treadmill to increase their own epinephrine concentration were not sensitized until exposures reached 50,000–100,000 ppm. In another endogenous-epinephrine study, a concentration of 800,000 ppm (80% FC-113:20% oxygen) was shown to sensitize the beagle heart after its epinephrine concentration was increased by fright (Mullin et al., 1972). Rats and mice were exposed at 200,000 ppm for 2.5 h/d, 5 d/wk, for 2 wk (Paulet and Desbrousses, 1969). Slight blood and body-weight changes were seen, as well as slight evidence of lung irritation. Exposure at 100,000 ppm had no effect, even after 2 mo of exposure (Paulet and Desbrousses, 1969). Dogs and guinea pigs were exposed at 141,600 ppm for 8 h/d for 21 d (Yant, 1933). The severity of the clinical signs attributable to CNS effects decreased during the 21 d of exposure. In the dogs, slight hematologic changes were observed, but the measures in question returned to normal 15–17 d after exposure; no gross pathologic changes were seen. No effects were seen in dogs, cats, guinea pigs, or rats exposed at 100,000 ppm for 3.5 h per exposure for 20 exposures (Scholz, 1962). No effects were seen in rats and rabbits exposed at 10,000 ppm for 2 h/d, 5 d/wk, during 8–9 mo (Desoille et al., 1973). INHALATION EXPOSURE LIMITS The ACGIH TLV-TWA (ACGIH, 1980, 1983) and the OSHA Federal Standard (OSHA, 1983) for FC-114 are both 1,000 ppm. ACGIH recommended a TLV-STEL for 15-min excursions of 1,250 ppm (ACGIH, 1983). The TLV-TWA was “recommended as exposure level which should provide a margin of safety in preventing systemic toxicity and an adequate margin in preventing cardiac sensitization” (ACGIH, 1980).
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Emergency and Continuous Exposure Limits for Selected Airborne Contaminants: Volume 2 COMMITTEE RECOMMENDATIONS The Committee on Toxicology previously established EELs and CEL for FC-114 in 1966. On the basis of positive 5-min cardiac-sensitization studies in dogs at 45,000 ppm and the absence of effects in dogs, cats, guinea pigs, or rats exposed to FC-114 at 10,000 ppm 3.5 h/day for 20 d, the Committee recommends a 60-min EEL of 10,000 ppm and a 24-h EEL of 1,000 ppm. In the absence of long-term exposure data, it appears appropriate to recommend a CEL of 100 ppm for 90 d. The present Committee’s recommended EELs and CEL for FC-114 and the limits proposed in 1966 are shown below. 1966 1984 60-min EEL 30,000 ppm 10,000 ppm 24-h EEL 20,000 ppm 1,000 ppm 90-d CEL 1,000 ppm 100 ppm
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Emergency and Continuous Exposure Limits for Selected Airborne Contaminants: Volume 2 REFERENCES American Conference of Governmental Industrial Hygienists. 1980. Dichlorotetrafluoroethane. Documentation of the Threshold Limit Values. 4th ed. Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists. p. 135. American Conference of Governmental Industrial Hygienists. 1983–1984. TLVs(R): Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment with Intended Changes for 1983–1984. Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists. 93 p. Desoille, H., Truffert, L., Girard-Wallon, Cl., Ripault, J., and Philbert, M. 1973. Recherche expérimentale de la toxicité chronique Sventuelle du dichlorotétrafluoroéthane. Arch. Mal. Prof. Med. Trav. Secur. Soc. 34:117–125. Dollery, C.T., Draffan, G.H., Davies, D.S., Williams, P.M., and Conolly, M.E. 1970. Blood concentrations in man of fluorinated hydrocarbons after inhalation of pressurized aerosols. Lancet 2:1164–1166. Griffith, F.D., and Sherman, H. 1969. The effect of (ethane-1,2-dichlorotetrafluoro) on growth rate, urinary fluoride, and bone fluoride in rats. Report No. 381–69. Newark, Delaware: E.I.du Pont de Nemours & Co., Haskell Laboratory for Toxicology and Industrial Medicine,  p. [Unpublished] Haskell Laboratory for Toxicology and Industrial Medicine. 1955a. Acute oral toxicity of FreonR-114, dichlorotetrafluoroethane. Newark, Delaware: E.I.du Pont de Nemours & Co. [Unpublished] Haskell Laboratory for Toxicology and Industrial Medicine. 1955b. Eye irritation of FreonR—114 in rabbits. Newark, Delaware: E.I.du Pont de Nemours & Co. [Unpublished] Hood, D.B. 1967. Skin tests with Rexall facial cleanser containing “Freon-114”. Report No. 110–67. Newark, Delaware: E.I.du Pont de Nemours & Co., Haskell Laboratory for Toxicology and Industrial Medicine.  p. [Unpublished] Morgan, A., Black, A., and Belcher, D.R. 1972a. Studies on the absorption of halogenated hydrocarbons and their excretion in breath using 38C1 tracer techniques. Ann. Occup. Hyg. 15:273–282. Morgan, A., Black, A., Walsh, M., and Belcher, D.R. 1972b. The absorption and retention of inhaled fluorinated hydrocarbon vapours. Int. J. Appl. Radiat. Isot. 23:285–291.
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Emergency and Continuous Exposure Limits for Selected Airborne Contaminants: Volume 2 Mullin, L.S., Azar, A., Reinhardt, C.F., Smith, P.E., Jr., and Fabryka, E.F. 1972. Halogenated-hydrocarbon induced cardiac arrhythmias associated with release of endogenous epinephrine. Am. Ind. Hyg. Assoc. J. 33:389–396. Occupational Safety and Health Administration. 1983. Toxic and Hazardous Substances. Air contaminants. 29 CFR 1910.1000. Paulet, G. 1970. Action of fluorochlorohydrocarbons used in aerosols. Problems of their retention by the organism after inhalation. Trib. CEBEDEAU 23:487–497. [Chem. Abs. 74:97243v, 1971] Paulet, G., and Desbrousses, S. 1969. Le dichlorotétrafluoroéthane. Toxicité aiguë et chronique à moyen terme. Arch. Mal. Prof. Med. Trav. Secur. Soc. 30:477–492. Paulet, G., Chevrier, R., Paulet, J., Duchêne, M., and Chappet, J. 1969. De la retention des fréons par les poumons et les voies aériennes. Étude faite chez l’homme et l’animal. Arch. Mal. Prof. Med. Trav. Secur. Soc. 30:101–120. Quevauviller, A. 1965. [Hygiene and safety of propellants in medicated aerosols.] Prod. Probl. Pharm. 20:14–17. Quevauviller, A., Schrenzel, M., and Vu Ngoc Huyen. 1964. Tolerance locale (peau, muqueuses, plaies, brulures chez l’animal, aux hydrocarbures chlorofluores). Therapie 19:247–263. [Index Medicus 5:1067, 1964]. Reinhardt, C.F., Azar, A., Maxfield, M.E., Smith, P.E., Jr., and Mullin, L.S. 1971. Cardiac arrhythmias and aerosol “sniffing.” Arch. Environ. Health 22:265–279. Scholz, J. 1962. New toxicologic investigations of freons used as propellants for aerosols and sprays. Translation of: Fortschr. Biol. Aerosol-Forsch. Jahren 1957–1961, Ber. Aerosol-Kongr. p. 4:420–429. Sherman, H. 1972. Ninety-day feeding study in rats and dogs with dichlorotetrafluoroethane [FreonR 114]. Report No. 5–72. Newark, Delaware: E.I.du Pont de Nemours & Co., Haskell Laboratory for Toxicology and Industrial Medicine.  p. [Unpublished] Underwriters’ Laboratories. 1933. Report on the Comparative Life, Fire and Explosion Hazard of Common Refrigerants Including… Dichlorotetrafluoroethane…. Miscellaneous Hazard no. 2375, Chicago, Nov. 13. Yant, W.P. 1933. Toxicity of organic fluorides. Am. J. Public Health 23:930–934. Yant, W.P., Schrenk, H.H., and Patty, F.A. 1932. Toxicity of dichlorotetrafluoroethane. U.S. Bureau of Mines Report of Investigations, R.I. 3185. 10 p.
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