Inhalation toxicity of adiponitrile in rats

Abstract

Adiponitrile, a chemical intermediate used in the manufacture of hexamethylenediamine, has moderate acute toxicity both orally and dermally. The acute inhalation toxicity was determined by exposing groups of young adult male ChR-CD rats for single 4-hr periods. The LC50 was 1.71 mg/liter. Male rats were exposed to either 0 (control), 0.03, 0.1, or 0.3 mg vaporized adiponitrile/liter for ten 6-hr periods (5 exposure days, 2 rest days, 5 exposure days). Clinical signs during exposure included irregular respiration and mild salivation. Rats exposed to 0.3 mg/liter showed weight loss during the first 5 exposures followed by a normal rate of weight gain. After 10 exposures, rats in this group had the following clinical pathologic changes: increased blood glucose, urea nitrogen, creatinine, and urine glucose; decreased erythrocyte count, hemoglobin, leukocyte count, relative number of eosinophils, and urine osmolality. Rats exposed to 0.1 mg/liter had increased urea nitrogen and lymphocytes and decreased numbers of neutrophils and eosinophils. No changes in clinical pathology parameters were seen in rats exposed to 0.03 mg/liter. Rats from all groups had normal values 14 days following the last exposure. Pathologic examination failed to reveal any compound-related changes.