Trifluorobromomethane

CAS number: 75-63-8

NIOSH REL: 1,000 ppm (6,100 mg/m³) TWA

Current OSHA PEL: 1,000 ppm (6,100 mg/m³) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 1,000 ppm (6,090 mg/m³) TWA

Description of substance: Colorless, odorless gas.

LEL:. . Nonflammable Gas

Original (SCP) IDLH: 50,000 ppm

Basis for original (SCP) IDLH: Hine et al. [1968] observed that "an exposure for 20 to 25 minutes to 50,000 ppm produced a minimal decrease in judgment and skill in some subjects, and stated that a 5-minute exposure to 70,000 ppm or less can be expected to produce a negligible central nervous system effect. A 3-minute exposure to 60,000 ppm has been shown to produce very slight dizziness." Based on these data, an IDLH of 50,000 ppm has been assumed for this draft technical standard.

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

30-minute EEGL: 40,000 ppm

1-hour EEGL: 25,000 ppm

ACUTE TOXICITY DATA:

Lethal concentration data:

Species	Reference	LC50 (ppm)	LCLo (ppm)	Time	Adjusted 0.5-hr LC (CF)	Derived value
Rat	Chambers et al. 1950	-----	834,000	15 min	658,860 ppm (0.79)	65,886 ppm
Cat	NRC 1984	LC100: 370,000	-----	7 hr	888,000 ppm (2.4)	88,000 ppm
G. pig	NRC 1984	LC100: 370,000	-----	7 hr	888,000 ppm (2.4)	88,000 ppm
Mouse	NRC 1984	LC80: 370,000	-----	7 hr	888,000 ppm (2.4)	88,000 ppm
Rat	NRC 1984	LC40: 370,000	-----	7 hr	888,000 ppm (2.4)	88,000 ppm
Rabbit	NRC 1984	LC100: 370,000	-----	7 hr	888,000 ppm (2.4)	88,000 ppm

Other animal data: Dogs and rats exposed daily for 18 weeks at an average concentration of 23,000 ppm showed no toxic signs and no pathologic changes observable at autopsy [Comstock et al. 1953].

Human data: Volunteers exposed to 70,000 ppm for 3 minutes experienced lightheadedness and disturbances in balance and ability to respond to visual stimulus [Reinhardt and Reinke 1972]; 3 hours to 70,000 ppm caused decrements in mental performance tests [Harrison et al. 1982]. Exposure to 50,000 ppm for 20 to 25 minutes caused drowsiness, light-headedness, and a slight effect on judgment [Hine et al. 1968]. Three volunteers experienced mild nose and throat discomfort after 28 minutes of exposure to 71,000 ppm [Stewart et al. 1978]. Others reported that a 30-minute exposure at 43,000 to 45,000 ppm caused dizziness, light-headedness, euphoria, and disturbances in equilibrium and coordination [Stewart et al. 1978].

Revised IDLH: 40,000 ppm Basis for revised IDLH: The revised IDLH for trifluorobromomethane is 40,000 ppm based on acute toxicity data in humans [Harrison et al. 1982; Hine et al. 1968; Reinhardt and Reinke 1972; Stewart et al. 1978].

REFERENCES:

1. Chambers WH, Krachow EH, McGroth FP, Goldberg SB, Lawson LH, McNamee K [1950]. An investigation of the toxicity of proposed fire extinguishing fluids. Part II. The approximate lethal concentration of undecomposed and pyrolyzed vapors of various compounds proposed for use as fire extinguishing agents. Army Chemical Center, MD: U.S. Army Chemical Corps, Medical Division Research Report No. 23, p. 16.

2. Comstock CC, Kerschner J, Oberst FW [1953]. Toxicology of inhaled trifluoromonobromomethane and difluoromonobromomethane vapors from subacute and chronic exposures of rats and dogs. Army Chemical Center, MD: U.S. Army Chemical Corps, Medical Laboratories, Research Report No. 180, p. 11.

3. Harrison JN, Smith DJ, Strong R, Scott M, Davey M, Morgan C [1982]. The use of Halon 1301 for firefighting in confined spaces. J Soc Occup Med 32:37-43.

4. Hine CH, Elliott HW, Kaufman JW, Leung S, Harrah MD [1968]. Clinical toxicologic studies on freon, FE 1301. In: Proceedings of the 4th Annual Conference on Atmospheric Contamination in Confined Spaces, 10-12 September 1968. Wright-Patterson Air Force Base, OH: Air Force Systems Command, Aerospace Medical Division, Aerospace Medical Research Laboratories, AMRL-TR-68-175, pp. 127-142.

5. NRC [1984]. Emergency and continuous exposure limits for selected airborne contaminants. Vol. 3. Bromotrifluoromethane. Washington, DC: National Academy Press, Committee on Toxicology, Board on Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, pp. 1-22.

6. Reinhardt CF, Reinke RE [1972]. Toxicology of halogenated fire extinguishing agents Halon 1301 (bromotrifluoromethane). In: An Appraisal of Halogenated Fire Extinguishing Agents. Committee on Fire Research and Committee on Toxicology. Washington, DC: National Academy of Sciences, pp. 67-78.

7. Stewart RD, Newton PE, Wu A, Hake CL, Krivanek ND [1978]. Human exposure to Halon 1301. Milwaukee, WI: Medical College of Wisconsin, Department of Environmental Medicine. [Unpublished]. [From: NRC [1984]. Emergency and continuous exposure limits for selected airborne contaminants. Vol. 3. Bromotrifluoromethane. Washington, DC: National Academy Press, Committee on Toxicology, Board on Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, pp. 1-22.]