Inhalation Toxicology of Methylamine

Abstract

AbstractMethylamine (MA) is a colorless gas with many industrial applications, including that as an intermediate in the manufacture of many chemicals. To assess the toxicity of MA following inhalation, groups of 10 male rats each were exposed by nose-only inhalation 6 h/d, 5 d/wk for 2 wk to either 0 (control), 75, 250, or 750 ppm MA. Rats were sacrificed either immediately following exposure or following a 14-d recovery period. Parameters investigated included in-life observations and body weights, clinical pathology, and histopathology with organ weights. Toxic effects including mortality were produced by exposure to 750 ppm. Severe body weight losses, clinical pathologic changes suggestive of liver damage, nasal degenerative changes, and hemato-poietic changes, not all of which were reversible during the recovery period, were observed. Exposure to 250 ppm produced damage, restricted to the respiratory mu-cosa of the nasal turbinates. Only a mild irritation to the nasal turbinate area was produced by 75...