Acute Toxicity Testing of Pink Salmon (Oncorhynchus gorbuscha) with the Tire Rubber–Derived Chemical 6PPD‐Quinone.

N‐(1,3‐dimethylbutyl)‐N′‐phenyl‐p‐phenylenediamine‐quinone (6PPD‐quinone) is a widespread contaminant of emerging concern resulting from oxidation of 6PPD, which is an antidegradant substance added to tires. The recent identification of 6PPD‐quinone as the cause of acute mortality in coho salmon has quickly motivated studies on 6PPD‐quinone toxicity to other species. Subsequent findings have shown that 6PPD‐quinone toxicity is highly species specific. Closely related species can differ widely in response to 6PPD‐quinone from extremely sensitive to tolerant. Hence toxicity testing is currently the only way to establish whether a species exhibits 6PPD‐quinone toxicity. We investigated the acute toxicity of 6PPD‐quinone in pink salmon alevins (sac fry). This species has is the only Pacific salmon that so far has not been tested for 6PPD‐quinone sensitivity. Fish were exposed in static water in eight treatments with initial concentrations ranging from 0.1 to 12.8 μg/L. Fish were observed for 48 h, and changes in concentrations of 6PPD‐quinone were monitored throughout the experiment. No mortalities or substantial changes in behavior were recorded. Environ Toxicol Chem 2024;43:1332–1338. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]