[Comparative assessment of enteral and inhaled n-butanol in laboratory animals]

Enteral and inhaled n-butanol given to albino rats was tested for toxicity in 2 series of subacute 30-day toxicological experiments. Enteral and inhalant administration caused membrano-, hepato-, adrenotoxic effects, and inhalant administration produced neurotoxic ones. The threshold dose was 0.2 mg/kg, the maximum ineffective one was 0.04 mg/kg. The threshold concentration was not established in the experiment. The less than 95% confidence limits of reference points (BMDL and BMCL), which cause a 10%-increase in the frequency of adverse reactions (blood catalase induction), were 0.052 mg/kg with enteral administration and 0.18 mg/m3 (0.076 mg/kg) on inhalation. The comparative toxicity coefficient (BMDLent/BMDLinh = 0.68) for n-butanol suggests that there is no difference in toxicity on different routes of administration.