OSHA comments from the January 19, 1989 Final Rule on Air Contaminants Project extracted from 54FR2332 et. seq. This rule was remanded by the U.S. Circuit Court of Appeals and the limits are not currently in force.
CAS: 74-96-4; Chemical Formula: C2H5Br
OSHA formerly had an 8-hour TWA limit of 200 ppm for ethyl bromide. The ACGIH also has a limit of 200 ppm as an 8-hour TWA and 250 ppm as a 15-minute STEL. The proposal retained the PEL of 200 ppm and added a STEL of 250 ppm; these limits are established by the final rule. Ethyl bromide is a colorless, highly volatile, flammable liquid with an ether-like odor; it becomes yellow when exposed to light and air.
The concentrations of ethyl bromide reported as lethal to guinea pigs are 3200 ppm for 9 hours and 1700 ppm for 12.5 hours (Sayers, Yant, Thomas, and Berger 1929/Ex. 1-803). von Oettingen (1955/Ex. 1-876) reported the minimal lethal concentration of this substance for mice as 3500 ppm.
Ethyl bromide acts as a central nervous system depressant (narcotic); additionally, exposure causes irritation of the lungs and congestion and fatty degeneration of the liver, intestinal hemorrhage, and kidney swelling. Several deaths have been reported from the use of ethyl bromide as a general anesthetic (von Oettingen 1955/Ex. 1-876). The record contains no submissions on the health effects of ethyl bromide exposure other than a submission from NIOSH (Ex. 8-47, Table N2; Tr. 3-86) indicating its nonconcurrence. NIOSH noted that one study (Karimullna and Gizatullina 1969) demonstrated liver injury and disrupted liver function in rats exposed 4 hours daily for 6 months to 540 ppm ethyl bromide. NIOSH also reported that an NTP inhalation bioassay to assess the carcinogenicity of ethyl bromide in rats and mice exposed at 100, 200, or 400 ppm was scheduled for peer review in October 1988. OSHA will review this study and any others that become available on this substance to determine whether further action is warranted.
In the final rule, OSHA is retaining its PEL of 200 ppm as an 8-hour TWA and adding a 15-minute STEL of 250 ppm for ethyl bromide. The Agency concludes that these limits will work together to reduce the significant risks of narcosis, kidney and liver damage, and respiratory irritation, all material impairments of health that are associated with occupational exposure to elevated levels of ethyl bromide.