Bromotrichloromethane

Abstract

Bromotrichloromethane (BrCCl3), an extremely potent liver poison, is a colorless, nonflammable liquid. It is sparingly soluble in water and readily evaporates when exposed to air. Compared to carbon tetrachloride, bromotrichloromethane produces about three times the degree of liver microsomal lipid peroxidation in biological samples. BrCCl3 is metabolized predominantly by CYP450 enzymes in vitro and in vivo, yielding phosgene (COCl2) and trichloromethyl free radicals. These reactive radicals ultimately react with glutathione and cause toxicity by depleting cellular glutathione. BrCCl3 is a chain transfer agent for radical polymerization of methacrylates. BrCCl3 is also a powerful brominating reagent, particularly for active hydrogen compounds. It is used for the preparation of a dichloromethylenephosphorane, a Wittig reagent. Toxic effects may result from the accidental ingestion of the material; animal experiments indicate that ingestion of less than 40 g may be fatal or may produce serious damage to the health of the individual. Skin contact with the material may produce toxic effects; systemic effects may result following absorption. This material can cause inflammation of the skin on contact in some persons, and may accentuate any preexisting dermatitis condition. Exposure into the bloodstream via any route (cuts, abrasions, or lesions) may produce systemic injury with harmful effects. Inhalation of vapors or aerosols (mists, fumes), generated by the material during the course of normal handling, may produce respiratory irritation and severe toxic effects. Based on effects in experimental animals, this compound may induce coma and possibly death in humans exposed to 20 000 ppm for 60 min. Exposure to 10 000 ppm for 30 min will provoke marked incoordination, and 2000 ppm for 5 min may produce disturbance of equilibrium.