WASHINGTON – The Washington Department of Ecology (Ecology) presented data before the US Senate Environment and Public Works committee on a chemical commonly found in car tires that could be causing severe damage to the state’s salmon populations.
The Wednesday hearing was meant to evaluate potential policy solutions to the Chemical 6PPD, which is used to prevent breakdown in most car tires and can release a highly toxic substance called 6PPD-quinone that kills salmon in Washington waterways according to Ecology.
Katrina Lassiter, Ecology’s program manager for Hazardous Waste and Toxics Reduction, offered context for how the chemical has impacted the Evergreen State.
“For more than twenty years, scientists faced a mystery. Coho salmon in Washington streams and rivers were dying. The culprit was unknown, but it seemed linked to toxic chemicals running off roadways and into rivers and streams,” Lassiter said.
University of Washington-Tacoma and Washington State University researchers spent three years working to identify 6PPD-quinone, which was contaminating migrating salmon. According to Lassiter, the toxic chemical can kill coho salmon within hours of exposure.
UW-Tacoma’s Center for Urban Waters and WSU have been exploring potential alternatives to 6PPD since 2020 alongside Ecology, but the toxic byproduct continues to threaten coho salmon through stormwater runoff.
Lassiter’s testimony illustrated the impact of the chemical commonly found in car tires by calling for federal research on potential alternatives to 6PPD-quinone and more stringent regulations for stormwater runoff.
“It is one of the most toxic chemicals to aquatic life that has ever been identified,” Lasiter said.
The US Environmental Protection Agency has coordinated with sovereign nations across the country to spread awareness of the dangers of 6PPD-quinone, but there has not been any major policy to address the toxic chemicals seeping into waterways nationally.
A cohort of tribes from Washington and California petitioned the EPA to ban 6PPD under the Toxic Substances Control Act in Aug. 2023.
“It is present not only in stormwater runoff and urban watersheds at levels that can kill salmon, steelhead trout, and other aquatic organisms, but also in sediments and soils, road and household dust, and the urine of pregnant women, with…potential risk to human health as well,” the petition said.
Washington Attorney General Bob Ferguson’s office filed an Oct. 2023 letter to the EPA alongside four other attorneys general supporting a ban on 6PPD.
While the EPA has committed to “take action to address the risk to the environment presented by 6PPD,” any proposed ban on 6PPD has met resistance from tire companies.
The US Tire Manufacturers Association argues that the substance is critical to making safe tires that are able to avoid temperature fluctuation damage and has warned regulators that a ban on 6PPD would pose a danger to drivers.
While state and federal policymakers and regulators debate the merits of allowing, curbing or banning the chemical, Ecology is coordinating with the Washington State Department of Transportation to find ways of mitigating toxic runoff.
Governor Jay Inslee (D) highlighted Lassiter’s congressional testimony in a Wednesday social media post and called for federal attention on toxic runoff endangering salmon populations.
“Washington is taking action on toxic 6PPD, but the scale of the problem requires federal attention,” Inslee said.
