Chlorobromomethane

IDLH Documentation

CAS number: 74­97­5

NIOSH REL: 200 ppm (1,050 mg/m³) TWA

Current OSHA PEL: 200 ppm (1,050 mg/m³) TWA

1989 OSHA PEL: Same as current PEL

1993­1994 ACGIH TLV: 200 ppm (1,060 mg/m³) TWA

Description of Substance: Colorless to pale­yellow liquid with a chloroform­like odor.

LEL: . . Noncombustible Liquid

Original (SCP) IDLH: 5,000 ppm

Basis for original (SCP) IDLH: Patty [1963] reported that light narcosis could be produced in animals at 3,000 ppm, and pulmonary edema and deaths during exposure at 27,000 ppm; delayed deaths occurred after exposure to 20,000 ppm [Comstock et al. 1953]. Patty [1963] also reported that guinea pigs survived 1­hour exposures but 1 of 3 guinea pigs died after 2­hour exposures to 8,000 to 10,000 ppm [Matson and Dufour 1948]. NIOSH [1974] cited 1,550 ppm as the mouse LC_LO [Svirbely et al. 1947]. Scheel (member of the Standards Completion Program Respirator Committee), in an evaluation of the work of Van Stee [1974], determined a cardiac toxicity concentration for chlorobromomethane of 7,000 ppm. Based on an evaluation of the toxicological data cited above, an IDLH of 5,000 ppm was chosen.

Short­term exposure guidelines: None developed

ACUTE TOXICITY DATA

Lethal concentration data:

*Note: Conversion factor (CF) was determined with "n" = 1.6 [ten Berge et al. 1986].

Lethal dose data:

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

REFERENCES:

1. Comstock C, Fogleman RW, Oberst FW [1953]. Acute narcotic effects of monochloro-monobromomethane vapor in rats. AMA Arch Ind Hyg Occup Med 7:526­528.

2. Comstock CC, MacNamee JK, Ozburn EE, Fogelman RW, Oberst FW [1952]. Monochloro-monobromomethane: inhalation toxicity, pathology, and symptomatology in rats and mice. Army Chemical Center, MD: Chemical Corps Medical Laboratories, Research Report #113.

3. Comstock CC, Oberst FW [1953]. Comparative inhalation toxicities of four halogenated hydrocarbons to rats and mice in the presence of gasoline fires. AMA Arch Ind Hyg Occup Med 7:157­167.

4. Deichmann WB, Gerarde HW [1969]. Methylene chlorobromide (bromochloromethane). In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., pp. 390­391.

5. Matson AF, Dufour RE [1948]. The life hazards and nature of the products formed when chlorobromomethane extinguisher liquid is applied to fires. Chicago, Il: Underwriter's Laboratories Inc., Bulletin of Research No. 42, p. 19.

6. NIOSH [1974]. PA52500. Bromochloromethane. In: The toxic substances list, 1974 ed. Rockville, MD: U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 74­134, p. 476.

7. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., pp. 1271­1272.

8. Svirbely JL, Highman B, Alford WC, von Oettingen WF [1947]. The toxicity and narcotic action of mono­chloro­mono­bromo­methane with special reference to inorganic and volatile bromide in blood, urine and brain. J Ind Hyg Toxicol 29:382­389.

9. ten Berge WF, Zwart A, Appelman LM [1986]. Concentration-time mortality response relationship of irritant and systematically acting vapours and gases. J Haz Mat 13:301­309.

10. Van Stee EW [1974]. A review of the toxicology of halogenated fire extinguishing agents. Wright­Patterson Air Force Base, Ohio: Aerospace Medical Division, Aerospace Medical Research Laboratory, Air Force Systems Command, AMRL­TR­74­143.
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