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May 1994

Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)


CAS number: 75–69–4

NIOSH REL: 1,000 ppm (5,600 mg/m3) CEILING

Current OSHA PEL: 1,000 ppm (5,600 mg/m3) TWA

1989 OSHA PEL: 1,000 ppm (5,600 mg/m3) CEILING

1993-1994 ACGIH TLV: 1,000 ppm (5,620 mg/m3) CEILING

Description of Substance: Colorless to water-white, nearly odorless liquid or gas (above 75 F).

LEL: . . Noncombustible Liquid/Nonflammable Gas

Original (SCP) IDLH: 10,000 ppm

Basis for original (SCP) IDLH: Scheel (member of the Standards Completion Program Respirator Committee), in evaluating the work of Reinhardt et al. [1971], indicated cardiac toxicity occurred at 12,000 ppm. The chosen IDLH is based on that data.

Existing short-term exposure guidelines: National Research Council [NRC 1984] Emergency Exposure Guidance Levels (EEGLs):

1-hour EEGL: 1,500 ppm

24-hour EEGL: 500 ppm


Lethal concentration data:







Adjusted 0.5-hr







Barras 1974

Lester and Greenberg 1950

Scholz 1962







4 hr

20 min

2 hr

52,400 ppm (2.0)

96,000 ppm (0.96)

160,000 ppm (1.6)

5,240 ppm

9,600 ppm

16,000 ppm

Other animal data: Evidence of serious arrhythmia was noted in 1 of 12 conscious dogs exposed for 5 minutes to 5,000 ppm plus intravenous epinephrine [Reinhardt et al. 1971]. However, in another study, endogenous epinephrin was not sufficient to precipitate arrythmia in dogs exposed to 5,000 to 10,000 ppm [Reinhardt et al. 1971].

Human data: None relevant for use in determining the revised IDLH.


Revised IDLH: 2,000 ppm

Basis for revised IDLH: The revised IDLH for fluorotrichloromethane is 2,000 ppm based on acute toxicity data in animals [Reinhardt et al. 1971] and to be consistent with a closely-related chlorofluorocarbon, 1,1,2-trichloro-1,2,2-trifluoroethane which has a revised IDLH of 2,000 ppm.


1. Barras CE [1974]. Unpublished data. Wilmington, DE: DuPont Company, Haskell Laboratory (October 1974). [From ACGIH [1986]. Documentation of the threshold limit values for substances in workroom air. 5th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 598.]

2. Lester D, Greenberg LA [1950]. Acute and chronic toxicity of some halogenated derivatives of methane and ethane. AMA Arch Ind Hyg Occup Med 2:335-344.

3. Mullin LS, Azar A, Reinhardt CF, Smith PE, Fabryka EF [1972]. Halogenated hydrocarbon-induced cardiac arrhythmias associated with release of endogenous epinephrine. Am Ind Hyg Assoc J 33(6):389-396.

4. NRC [1984]. Emergency and continuous exposure limits for selected airborne contaminants. Vol. 2. Washington, DC: National Academy Press, Committee on Toxicology, Board on Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, pp. 26-33.

5. Reinhardt CF, Azar A, Maxfield ME, Smith PE, Mullin LS [1971]. Cardiac arrhythmias and aerosol "sniffing." Arch Environ Health 22:265-279.

6. Scholz J [1962]. New toxicological investigations on certain types of freon used as propellants. Fortschr Biol Aerosol-forsch Jahren 1957-1961. Ber Aerosol Kongr 4:420-429. [From ACGIH [1991]. Trichlorofluoromethane. In:  Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 619-623.]

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