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Dichlorotetrafluoroethane
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 76–14–2
NIOSH REL: 1,000 ppm (7,000 mg/m3) TWA
Current OSHA PEL: 1,000 ppm (7,000 mg/m3) TWA
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 1,000 ppm (6,990 mg/m3) TWA
Description of Substance: Colorless gas with a faint, ether-like odor at high concentrations.
LEL:. . Nonflammable Gas
Original (SCP) IDLH: 50,000 ppm
Basis for original (SCP) IDLH: Dichlorotetrafluoroethane is known to be a narcotic in high concentrations, but no human exposure data are available concerning its narcotic effects. Based on an analogy with dichlorodifluoromethane, a related compound that produces dizziness in humans at 50,000 ppm [ILO 1971], an IDLH of 50,000 ppm is assumed for this draft technical standard.
Existing short-term exposure guidelines: National Research Council [NRC 1984] Emergency Exposure Guidance Levels (EEGLs):
1-hr EEGL: 10,000 ppm
24-hr EEGL: 1,000 ppm
ACUTE TOXICITY DATA
Lethal concentration data:
| Species | Reference | LC50(ppm) | LCLo(ppm) | Time | Adjusted 0.5-hrLC (CF) | Derivedvalue |
|---|---|---|---|---|---|---|
| RatMouse
Rabbit |
Paulet 1976Paulet 1976
Paulet 1976 |
720,000700,000
750,000 |
———-
—– |
30 min30 min
30 min |
720,000 ppm (1.0)700,000 ppm (1.0)
750,000 ppm (1.0) |
72,000 ppm70,000 ppm
75,000 ppm |
Other animal data: Evidence of serious arrhythmia was noted in 1 of 12 dogs exposed for 5 minutes to 25,000 ppm plus intravenous epinephrine [Reinhardt et al. 1971]. Cardiac sensitization has been induced with endogenous epinephrine at 50,000 to 800,000 ppm [Mullin et al. 1972; Reinhardt et al. 1971].
Human data: Significant reduction in ventilatory lung capacity, bradycardia, and increased variability in heart rate have been reported following exposures to 2,300 to 21,400 ppm for 15, 45, or 60 seconds [IPCS 1990].
| Revised IDLH: 15,000 ppmBasis for revised IDLH: The revised IDLH for dichlorotetrafluoroethane is 15,000 ppm based on acute inhalation toxicity data in animals [Reinhardt et al. 1971] and an analogy to dichlorodifluoroethane, another closely related halogenated hydrocarbon, which has a revised IDLH of 15,000 ppm. |
REFERENCES:
1. ILO [1971]. Fluorocarbons. In: Encyclopaedia of occupational health and safety. 2nd ed. Vol. I (A-K). Geneva, Switzerland: International Labour Office, pp. 560-562.
2. IPCS [1990]. Environmental criteria 13. Fully halogenated chlorofluorocarbons. Geneva, Switzerland: World Health Organization, International Programme on Chemical Safety.
3. Mullin LS, Azar A, Reinhardt CF, Smith PE Jr, Fabryka EF [1972]. Halogenated hydrocarbon-induced cardiac arrhythmias with release of endogenous epinephrine. Am Ind Hyg Assoc J 33:389-396.
4. NRC [1984]. Emergency and continuous exposure limits for selected airborne contaminants. Vol. 1. Washington, DC: National Academy Press, Committee on Toxicology, Board on Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, pp. 51-55.
5. Paulet G [1976]. Les fluorocarbones en question. J Eur Toxicol (Supplement) 9(7):385-407 (in French).
6. Reinhardt CF, Azar A, Maxfield ME, et al. [1971]. Cardiac arrhythmias and aerosol sniffing. Arch Environ Health 22:265-279.