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A single oral dose of 14C-TBPA was administered to male and female rats. The test article was hydrolyzed to the acid form and partly absorbed in the gastro-intestinal tract. The absorbed portion was readily eliminated in the urine (~20%) within 24 hrs, and the unabsorbed portion was eliminated in the feces within 48 hrs (~75%). The 14C-activity in the urine consisted of 27% acid released TBPA-acid, 27% water solubles and 45% of the 14C-activity was lost upon acidification to pH 1.0. The lost 14C-activity was determined to be recoverable with a methanol rinse of extraction vessels and analysis of the aqueous/organic layer interface. The 14C-activity in the feces consisted of 25% acide released TBPA-acide, 20% unextractable solids and again 55% was lost upon acidification. There was no significant difference in the pharmacokinetics between male and female rats. Total residues in all tissues amounted to <0.2% of the dose 2 days after treatment. Blood concentrations of TBPA-equivalents peaked 2 hrs after dosing at 3.462 ppm then gradually decreased to 0.013 ppm after 72 hrs. The portion absorbed appeared to follow a one compartment open model. The test article was rapidly distributed in the body and the rate of elimination in urine was proportional to the concentration in the blood. The rate constant for elimination was 0.081 and the half life in blood was 8.5 hr. The absorbed 14C-activity (>20%) should neither be persistent nor accumulative since the maximum half life in any tissue was < 7 hrs. The extrapolated maximum residues (plateau) could be reached within 2 d in a continuous feeding study of daily dosing.