Inhalation Toxicology of 1,4-Butanediol

Abstract

1,4-Butanediol is a clear, slightly viscous liquid with a low vapor pressure used in manufacturing polyester glycols and polyurethanes. The material has a low order of acute inhalation toxicity with a 4-h ALC of 15 mg/l in male rats. In the repeated dose study, groups of 10 male Crl:CD rats were exposed nose-only, 6 h/day, 5 days/wk for 2 wk to aerosol concentrations of either 0, 0.20, 1.7, or 5.2 mg/l. Rats were given pathological, urinalysis, and clinical chemical examinations after the last (tenth) exposure and after a 2-wk recovery period. No adverse effects were observed in rats exposed to either 0.20 or 1.1 mg/l. Rats exposed to 5.2 mg/l had depressed body weight evident after the third exposure. After 10 exposures, these rats had increased erythrocyte count and hematocrits and decreased serum cholesterol concentrations. Pathological examination showed slight atrophy of lymphoid cells in the thymus and depressed mean heart weights in these rats. No adverse effects were observed after 2 wk of recovery. Both 0.20 and 7.1 mg/l were no-adverse-effect concentrations under the conditions of this test. At 5.2 mg/l, rats showed nonspecific reversible systemic effects.