Presenter: Tanya Williams, Ecology

In 2020, researchers in the Pacific Northwest identified 6PPD-quinone as the long-sought cause of coho salmon deaths during spawning runs. This chemical—formed when 6PPD, a common tire additive, reacts with ozone—is now recognized as the second most toxic substance to aquatic life worldwide. The discovery has sparked a global effort to address its impacts. Federal, State, Tribal, and Local governments, along with researchers and community partners, are working to restrict 6PPD use in tires and advance stormwater control technologies that can reduce or remove 6PPD-quinone before it reaches waterways. Ecology’s 6PPD lead agency planner and stormwater engineer will share Washington State’s legislative directive to accelerate solutions that protect salmon and the ecosystems that depend on them. The session will review emerging Tribal, federal, and state actions to restrict the use of 6PPD in tires and present the latest results from stormwater best management practice research aimed at reducing 6PPD-quinone exposure in sensitive watersheds to protect aquatic life from harm.