Inhaled tert-butyl acetate and its metabolite tert-butyl alcohol accumulate in the blood during exposure.

1. A continuous 5 h-exposure to approximately 440 ppm tert-butyl acetate in air (via a tracheal canule) resulted in continuously increasing concentrations of tert-butyl acetate and tert-butyl alcohol (metabolite of tert-butyl acetate) in the blood of rats. 2. This accumulation of tert-butyl acetate and tert-butyl alcohol was reproduced during a continuous exposure to about 900 ppm tert-butyl acetate in air over a period of 4 h and 15 min. After the inhalation approximately 50% of the blood level of tert-butyl acetate decreased within 45 min, but that of tert-butyl alcohol remained unchanged at a high level. 3. The accumulation of tert-butyl acetate and tert-butyl alcohol should be relevant for the health risk assessment at the workside.