Environmental dynamics of phosphate esters. III. Comparison of the bioconcentration of four triaryl phosphates by fish

Uptake, clearance and extent of metabolism of ¹⁴C-labelled t-butylphenyldiphenyl phosphate (t-BPDP), tri-m-cresyl phosphate (mTCP), tri-p-cresyl phosphate (pTCP) and triphenyl phosphate (TPP) were studied in rainbow trout ($\text{Salmo}$$\text{gairdneri}$) and fathead minnows ($\text{Pimephales}$$\text{promelas}$) using short-term static exposures (50 and 5 μmg/L). Bioconcentration factors for pTCP, mTCP, TPP and tBPDP calculated by use of total radioactivity in whole fish were 1420, 784, 573 and 1096 respectively, for rainbow trout and 928, 596, 561 and 1010 respectively, for fathead minnows. Differences in rates of clearance and biotransformation among the four compounds were more closely related to their ease of hydrolysis than to hydrophobicity.