Subchronic Inhalation Toxicity of Hexamethylenediamine in Rats

Four groups of 15 male and 15 female Sprague-Dawley-derived(CD) rats each were exposed to aqueous hexamethylenediamine(HMD) aerosols for 6 hr/thy, 5 days/week for 13 weeks at meananalytical concentrations of 0, 12.8, or 51 mg/m³ Because ofexposure-related deaths in a group of male and female rats similarlyexposed to 215 mg/m³ HMD, this group was terminated during theseventh week of the study. Signs of respiratory and conjunctivalirritation were observed in rats at both the 51 and 215 mg/m³HMD test levels. Body weight gain was significantly reducedin both sexes exposed to 215 mg/m³ HMD. At the 5-week studyinterval, slight hemopoietic stimulation of peripheral bloodparameters was observed in rats of both sexes exposed to 215mg/m³ HMD. Treatment-related microscopic lesions were seen onlyin rats exposed to 215 mg/m³ MD and were confined to the trachea,nasal passages, and lungs. The noeffect level in this studyis considered to be 12.8 mg/m³ HMD.