The Bioaccumulation and Metabolism of [14C]-6PPD-Qin Rainbow Trout according to the OECD 305 Guideline

6PPD-quinone (6PPD-Q) has been recognized as a pollutant of surface waters in recent years and has been shown to contribute to Urban Runo􀆯 Mortality Syndrome (URMS) in sensitive species. While there is published in silico, in vitro and semi-quantitative data available, little is known about the bioaccumulation and biotransformation (metabolism) of 6PPD-Q in intact salmonid species. This research focuses on the bioaccumulation and metabolism of carbon-14 ([14C]) radiolabeled 6PPD-Q using techniques and strategies commonly employed in regulatory science for the registration of agrochemicals, chemicals and as used in pharmaceutical environmental risk assessments. The OECD 305 test guideline (TG) is used as the basis for generating data on bioaccumulation but also lends itself to the generation of biotransformation data. Rainbow trout (Oncorhynchus mykiss) is commonly used as the model species for such studies and has also been shown to be acutely sensitive to 6PPD-Q. The use of [14C]-6PPD-Q allows the quantification of total residues without the need for reference standards and provides a means of assessing the bioaccumulation potential of 6PPD-Q. The use of radiolabeled material also allows assessment of extraction e􀆯iciency and quantitative metabolite profiling and identification without the need for reference standards providing full coverage of the metabolites generated from 6PPD-Q exposure in rainbow trout. The bioaccumulation potential and metabolic routes in rainbow trout are presented herein.