Experimental study on the pulmonary absorption and excretion of toluene.

Three exposure levels of toluene were inhaled by dogs for 1 h. Toluene concentrations in expired air, arterial blood and venous blood were repeatedly measured. Absorptions of toluene within one hour of exposure were 25, 56 and 74 mg/kg at 700, 1500 and 2000 ppm respectively (absorption ratio = 27%). The cumulative excretion one hour after exposure was 63% of the absorped material at all three exposure levels. Multiple regression analyses were performed to interconnect the independent variables.