Acute Toxicity Testing of the Tire Rubber–Derived Chemical 6PPD-quinone on Atlantic Salmon (Salmo salar) and Brown Trout (Salmo trutta)

Recent identification of 6PPD‐quinone as the chemical causing acute toxicity in coho salmon has led to substantialconcern regarding the toxicity of this contaminant for other aquatic species. Environmental occurrence of 6PPD‐quinone isprobably high, because it is an oxidation product of a common tire rubber additive. Research on 6PPD‐quinone toxicity infish has revealed a rather unusual pattern, with closely related species exhibiting responses ranging from extreme sensitivityto no effect. Of 11 previously studiedfish species, 6PPD‐quinone was toxic to four. The species‐specific toxicity of 6PPD‐quinone complicates urgently needed environmental risk assessment. We investigated the acute toxicity of 6PPD‐quinone inAtlantic salmon and brown trout alevins (sac fry). These species have previously not been tested for sensitivity to 6PPD‐quinone. Thefish were exposed in static conditions in eight treatments with initial concentrations ranging from 0.095 to12.16μg/L. Fish were observed for 48 h, and changes in concentrations of 6PPD‐quinone were monitored throughout theexperiment. No mortalities or substantial changes in behavior were recorded in either Atlantic salmon or brown trout. Thisprovides an importantfirst step in assessing effects of 6PPD‐quinone on these economically and culturally highly importantspecies.Environ Toxicol Chem2022;41:3041–3045. © 2022 The Authors.Environmental Toxicology and Chemistrypub-lished by Wiley Periodicals LLC on behalf of SETAC. 6PPDQ; 6PPD‐quinone; aquatic toxicology; contaminants of emerging concern; ecological risk assessment; toxiceffects; runoff;Salmo