Ethyl bromide

CAS number: 74–96–4

NIOSH REL: The 1989 OSHA PEL may not be protective to workers.

Current OSHA PEL: 200 ppm (890 mg/m³) TWA

1989 OSHA PEL: 200 ppm (890 mg/m³) TWA, 250 ppm (1100 mg/m³) STEL

1993-1994 ACGIH TLV: 5 ppm (22 mg/m³) TWA, A2

Description of Substance: Colorless to yellow liquid with an ether-like odor.

LEL:. . 6.8% (10% LEL, 6,800 ppm)

Original (SCP) IDLH: 3,500 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the minimal lethal concentration for mice of 3,500 ppm [Bachem 1927 as cited by von Oettingen 1937] cited by ACGIH [1971].

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA

Lethal concentration data:

Species	Reference	LC50 (ppm)	LCLo (ppm)	Time	Adjusted 0.5-hr LC (CF)	Derived value
Mouse Rat Mouse Rat Mouse G. pig G. pig G. pig G. pig	Bachem 1927 Back et al. 1972 Back et al. 1972 NTP 1988 NTP 1988 Sayers and Yant 1929 Sayers and Yant 1929 Sayers and Yant 1929 Sayers and Yant 1929	----- 26,980 16,230 4,681 2,723 LC100: 100,000 LC100: 140,000 ----- -----	3,500 ----- ----- ----- ----- ----- ----- 24,000 7,000	? 1 hr 1 hr ? ? 1.5 hr 10 min 30 min >4.5 hr	? 33,725 ppm (1.25) 20,288 ppm (1.25) ? ? 145,000 ppm (1.45) 96,600 ppm (0.69) 24,000 ppm (1.0) >14,560 ppm (2.8)	? 3,373 ppm 2,029 ppm ? ? 14,500 ppm 9,660 ppm 2,400 ppm >1,456 ppm

Other animal data: Exposure at 1,700 ppm for 9 hours caused no anesthesia or apparent adverse effects [Sayers and Yant 1929].

Human data: Concentrations of 12,000 ppm caused immediate eye irritation in volunteers and 5 minutes at 6,500 ppm resulted in eye irritation, headache, and vertigo [Sayers and Yant 1929]. Workers exposed intermittently to concentrations up to 1,500 ppm complained of no systematic symptoms over a period of several years [Watrous 1947].

Revised IDLH: 2,000 ppm Basis for revised IDLH: The revised IDLH for ethyl bromide is 2,000 ppm based on acute inhalation toxicity data in humans [Sayers and Yant 1929; Watrous 1947] and animals [Back et al. 1972; Sayers and Yant 1937]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations between 1,500 and 6,500 ppm.

REFERENCES:

1. ACGIH [1971]. Ethyl bromide. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 105.

2. Bachem C [1927]. Contribution to the toxicology of the alkyl halides. Arch Exp Pathol Pharmakol 122:73-76 (translated).

3. Back KC, Thomas AA, MacEwen JD [1972]. Reclassification of materials listed as transportation health hazards. Wright-Patterson Air Force Base, OH: 6570th Aerospace Medical Research Laboratory, Report No. TSA-20-72-3, pp. A-340 to A-341.

4. NTP [1988]. Technical report on the toxicology and carcinogenesis studies of bromoethane. Research Triangle Park, NC: National Toxicology Program, NTP/NIH Publication No. 89-2818.

5. Sayers R, Yant WP [1929]. Physiological response attending exposure to vapors of methyl bromide, methyl chloride, ethyl bromide, and ethyl chloride. Washington, DC: U.S. Government Printing Office, Treasury Department, US Public Health Service, Public Health Bulletin 185:1-56.

6. von Oettingen WF [1937]. The halogenated hydrocarbons: their toxicity and potential dangers. J Ind Hyg Toxicol 19(8):349-448.

7. Watrous R [1947]. Health hazards of the pharmaceutical industry. Br J Ind Med 4:111-125.