Pulmonary elimination of methyl tertiary-butyl ether after intraperitoneal administration in mice

The pulmonary elimination after intraperitoneal administration at three different doses (50, 100, and 500 mg/kg) of methyl tertiary-butyl ether (MTBE) was studied using mice. There were two exponential curves with an initial rapid decrease of the elimination ratio followed by a slow decrease at the doses of 100 mg/kg and 500 mg/kg. The calculated half-lives of the two elimination curves obtained by the least squares method were approximately 45 min and 80 min. The pulmonary elimination ratios at the three different doses were from 23.2% to 69.0%. Most of the excreted MTBE was eliminated within 3 h. It is suggested in this paper that MTBE in exhaled air can be used as a biological exposure index for the exposure assessment of MTBE.