CHLOROACETYL CHLORIDE

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: 79-04-9; Chemical Formula: ClCH₂COCl

No previous exposure limit existed for chloroacetyl chloride. OSHA proposed a 0.05-ppm 8-hour TWA limit for this substance, based on the ACGIH recommendation, and NIOSH (Ex. 8-47, Table N1) concurred with this proposal. This limit is established in the final rule. Chloroacetyl chloride is a colorless liquid with a pungent odor.

The oral LD(50) in rats fed this substance is between 0.12 and 0.25 g/kg. Chloroacetyl chloride is corrosive to the skin and eyes, and skin absorption of this substance can be lethal. Inhalation of 4 ppm for five to ten minutes caused respiratory problems in rats; however, no effect was observed in these animals when they inhaled 2.5 ppm for a period of seven hours (Dow Chemical Company 1977a, as cited in ACGIH 1986/Ex. 1-3, p. 122). Thirty-day inhalation studies with rats, mice, and hamsters showed eye and respiratory irritation at 2.5 ppm and no effect at 0.5 ppm (Dow Chemical Company 1977a, as cited in ACGIH 1986/Ex. 1-3, p. 122).

Reports of the acute effects associated with exposure to chloroacetyl chloride in humans include mild to moderate skin burns and erythema, eye burns and tearing, cough, dyspnea, and cyanosis, as well as mild gastrointestinal effects. Eye and respiratory irritation occurred in an industrial setting characterized by an exposure level of 0.009 to 0.017 ppm, with excursions as high as 0.140 ppm (Dow Chemical Company 1977a, as cited in ACGIH 1986/Ex. 1-3, p. 122). An accidental drenching with a mixture containing chloroacetyl chloride resulted in extensive first- and second-degree burns, pulmonary edema, and three episodes of cardiac arrest, followed by coma and anoxia-induced brain damage (Pagnotto 1978, as cited in ACGIH 1986/Ex. 1-3, p. 122). Other ingredients of the mixture involved in the accident included xylidine, benzene, and sodium carbonate. Rescuers of this victim experienced hand blisters, chest tightness, and nausea for two days. OSHA received no comments other than NIOSH’s on the proposed 0.05-ppm TWA limit for chloroacetyl chloride.

The Agency concludes that an 8-hour TWA limit of 0.05 ppm for chloroacetyl chloride is necessary to protect employees from the significant risk of eye, skin, and respiratory irritation; gastrointestinal effects; and severe systemic effects, including life-threatening coma, cardiac arrest, and pulmonary edema, to which they could otherwise be exposed in the absence of any OSHA limit; the Agency considers each of these exposure related adverse effects to be material impairments of health and functional capacity. Accordingly, OSHA is establishing an occupational limit of 0.05 ppm as an 8-hour TWA for chloroacetyl chloride.