Comparison of laboratory and field results for prediction of the environmental behavior of phosphate esters

Abstract

AbstractTwo phosphate ester flame retardants, triphenyl phosphate (TPP) and 2‐ethylhexyldi‐phenyl phosphate (EHDPP) (both14C‐labelled) were added to two small artificial ponds (3 m3volume) to give water concentrations of 60 μg/L for each compound. Both phosphate esters had half‐lives of about 15 h in the water column and showed rapid sorption to bottom sediment. At 24 h posttreatment an estimated 28% of EHDPP and 9% of TPP added could not be accounted for by measurements of radioactivity in water, sediment and biota. Calculations of volatilization rates from water of the two compounds suggested that losses of EHDPP may have been due in part to volatilization. Bioconcentration of TPP by fathead minnows (Pimephales promelas) was similar to that predicted from laboratory studies on the uptake and clearance of TPP by rainbow trout (Salmo gairdneri). Prediction of the bioconcentration of EHDPP by duckweed (Lemna minor) from laboratory studies underestimated the rapid uptake of this compound observed in the ponds.