6PPD quinone: The environmental contaminant killing Coho salmon
6PPD is widely used to protect car tires from ozone. But when rainwater washes it into freshwater it degrades into 6PPD-quinone, a contaminant a recent study links to the mass deaths of Coho salmon in the Pacific Northwest. There is no know substitute for the chemical but regulators, including the California Department of Toxic Substances Control, are working with industry and researchers to address the issue.