The U.S. Environmental Protection Agency will begin the process to limit and possibly eliminate a chemical commonly used in car tires, after scientific studies found that the chemical — commonly known as 6PPD — is fatal to salmon.
The EPA announced its regulatory plans Thursday, answering a petition from three Native Tribes in the Pacific Northwest. The states of Washington, Oregon, Vermont, Rhode Island and Connecticut also supported the petition.
It likely will take years for the EPA’s rulemaking process to take effect; the agency’s first step will be to require tire manufacturers to share their unpublished health and safety studies, but that’s not expected before the end of 2024.
A University of Washington study, funded by the EPA and published in late December 2020, conclusively linked 6PPD to mass die-offs of coho salmon in urban waterways around Seattle.
The 6PPD chemical is used by all major tire manufacturers to reduce degradation and cracking. Tires deposit small amounts of rubber on the road with each revolution, and those deposits contain 6PPD, which then washes into neighboring waterways with snow and rain.
Limited testing has been done in Alaska, home to the nation’s largest salmon runs, but preliminary sampling in Anchorage in 2021 found levels of 6PPD that are lethal to coho salmon.