Current Intelligence Bulletin 43: Monohalomethanes

The purpose of this bulletin is to recommend that methyl chloride, methyl bromide, and methyl iodide be regarded as potential occupational carcinogens. Additionally, it is recommended that methyl chloride be considered a possible teratogen. These recommendations are based upon animal studies which have demonstrated the carcinogenic potential of these compounds and in the case of methyl chloride, teratogenic effects as well. Consequently, appropriate engineering and work practice controls should be used to reduce worker exposure The excess risk of cancer to workers or the induction of a teratogenic response in the children of workers exposed to specific airborne concentrations of these compounds has not yet been determined, but the probability of developing these adverse effects would be decreased by reducing exposure. NIOSH recommends that producers and users of methyl chloride, methyl bromide, and methyl iodide disseminate this information to their workers and customers and that professional and trade associations and unions inform their members of otential hazards of working with these compounds.

Current Intelligence Bulletin 43: Monohalomethanes