6PPD chemical linked to salmon deaths
The U.S. Environmental Protection Agency (EPA) committed on May 12, 2026, to developing regulations for the tire chemical 6PPD, whose byproduct 6PPD-quinone causes "urban runoff mortality syndrome" in coho salmon. As of June 13, 2026, 6PPD-quinone has been detected in the San Francisco Bay estuary, with levels highest after winter storms, and a federal trial in San Francisco is ongoing with fishing groups suing tire manufacturers. Environmental chemists testified that a single car's tires could produce enough 6PPD-quinone to kill millions of salmon, and studies indicate 40-90% of adult coho in urban watersheds may die annually from exposure. New data from May 2026 indicates 6PPD-quinone has been detected in the San Francisco Bay estuary, with levels highest near the shore after winter storms, following a January 2026 study revealing 6PPD-Q may be as harmful to juvenile coho salmon as adults.
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June 2026 — 1 developments
New data published in May 2026 indicates that 6PPD-quinone has been detected in the San Francisco Bay estuary, with levels highest near the shore after winter storms.
New data published in May 2026 indicates that 6PPD-quinone has been detected in the San Francisco Bay estuary, with levels highest near the shore after winter storms. This follows a January 2026 study revealing 6PPD-Q may be as harmful to juvenile coho salmon as adults, and a July 2025 study finding 6PPD-Q concentrations in a coho-bearing stream exceeded toxicity thresholds during rain events.
May 2026 — 1 developments
The U.S. Environmental Protection Agency (EPA) has committed to developing regulations for the tire …
The U.S. Environmental Protection Agency (EPA) has committed to developing regulations for the tire chemical 6PPD, following scientific findings that its byproduct, 6PPD-quinone, causes "urban runoff mortality syndrome" in coho salmon. This action comes in response to petitions from Native American tribes and follows California's classification of tires containing 6PPD as a "priority product."
April 2026 — 2 developments
Environment and Climate Change Canada has prioritized the chemical 6PPD for assessment due to its link to salmon mortality.
Environment and Climate Change Canada has prioritized the chemical 6PPD for assessment due to its link to salmon mortality. This initiative is running parallel to a federal trial in San Francisco where fishing groups are suing tire manufacturers over the use of 6PPD, which they claim transforms into toxic 6PPD-quinone.
Environmental chemists testified in a federal trial that a single car's tires could produce enough 6…
Environmental chemists testified in a federal trial that a single car's tires could produce enough 6PPD-quinone to kill millions of salmon, and that 6PPD-q is the second-most toxic chemical to aquatic species ever evaluated. The EPA is also reviewing the chemical 6PPD following a petition from Native American tribes.
February 2026 — 2 developments
Commercial fishing groups and environmental organizations have filed lawsuits against major tire man…
Commercial fishing groups and environmental organizations have filed lawsuits against major tire manufacturers, alleging that the chemical 6PPD breaks down into 6PPD-quinone, causing significant coho salmon deaths. A federal trial concluded in late January 2026, with ongoing legal actions highlighting the chemical's impact on both adult and juvenile salmon, with estimates suggesting 40-90% of adult coho in urban watersheds may die annually from exposure.
The federal court trial, which lasted three days, involves 13 tire manufacturers, including Bridgestone and Michelin, with plaintiffs represented by Earthjustice.
The federal court trial, which lasted three days, involves 13 tire manufacturers, including Bridgestone and Michelin, with plaintiffs represented by Earthjustice. During the trial, defense argued that laboratory studies may not accurately reflect real-world conditions, and a witness stated that 6PPD-quinone degrades quickly.
January 2026 — 4 developments
During the ongoing federal court trial, tire manufacturers argued there is insufficient data to defi…
During the ongoing federal court trial, tire manufacturers argued there is insufficient data to definitively link runoff chemicals from their products to the deaths of protected fish populations. Environmental groups countered that the chemical 6PPD transforms into 6PPD-quinone, harming salmon.
A '6PPD State of the Science Forum' was held, and a 2025 study by Puget Soundkeeper's annual Pre-Spawn Mortality Survey found that 55.
A '6PPD State of the Science Forum' was held, and a 2025 study by Puget Soundkeeper's annual Pre-Spawn Mortality Survey found that 55.5% of coho salmon died before spawning.
A federal court trial began in San Francisco on January 26, 2026, with West Coast fishers and conser…
A federal court trial began in San Francisco on January 26, 2026, with West Coast fishers and conservationists suing tire companies over allegations that the chemical additive 6PPD from tires is polluting rivers and killing coho salmon. U.S. District Judge James Donato is presiding over the case.
A new study indicates that juvenile coho salmon are also at risk from 6PPD-quinone, the toxic chemical derived from tire preservative 6PPD.
A new study indicates that juvenile coho salmon are also at risk from 6PPD-quinone, the toxic chemical derived from tire preservative 6PPD. Researchers found that approximately 80% of juvenile coho salmon exposed to creek water containing 6PPDQ during spring storms died within about six hours. This expands on earlier research that primarily focused on the impact of 6PPDQ on adult coho salmon.
July 2025 — 1 developments
Reports highlight the critical situation in British Columbia, with confirmed salmon deaths linked to…
Reports highlight the critical situation in British Columbia, with confirmed salmon deaths linked to tire pollutants in areas like Cowichan, Vancouver Island, indicating a broader geographic impact.
December 2024 — 1 developments
The EPA initiates a formal regulatory investigation into 6PPD and 6PPD-quinone under the Toxic Subst…
The EPA initiates a formal regulatory investigation into 6PPD and 6PPD-quinone under the Toxic Substances Control Act (TSCA), seeking public input on alternatives and regulatory measures.
October 2024 — 1 developments
The EPA intends to publish an advanced notice of proposed rulemaking in the fall of 2024 to gather more information for potential federal regulatory action on 6PPD.
The EPA intends to publish an advanced notice of proposed rulemaking in the fall of 2024 to gather more information for potential federal regulatory action on 6PPD.
August 2024 — 1 developments
Washington State adopts an aquatic life criterion for 6PPD-quinone, setting a state-level water quality standard to protect sensitive aquatic species.
Washington State adopts an aquatic life criterion for 6PPD-quinone, setting a state-level water quality standard to protect sensitive aquatic species.
May 2024 — 1 developments
The Canadian federal government decided in May 2024 to prioritize the assessment of 6PPD, a chemical linked to mass salmon deaths.
The Canadian federal government decided in May 2024 to prioritize the assessment of 6PPD, a chemical linked to mass salmon deaths. Environmental groups have expressed encouragement regarding this decision.
March 2024 — 1 developments
The initial screening of potential alternatives to 6PPD by tire manufacturers is due, marking a key step in the industry's response to regulatory pressure.
The initial screening of potential alternatives to 6PPD by tire manufacturers is due, marking a key step in the industry's response to regulatory pressure.
December 2023 — 1 developments
The EPA publishes an analytical procedure to test for 6PPD-quinone, providing a standardized method for environmental monitoring.
The EPA publishes an analytical procedure to test for 6PPD-quinone, providing a standardized method for environmental monitoring.
November 2023 — 2 developments
West Coast fishermen filed a lawsuit in November 2023 against 13 tire manufacturers, alleging that t…
West Coast fishermen filed a lawsuit in November 2023 against 13 tire manufacturers, alleging that the chemical 6PPD-quinone from tires is killing coho salmon, Chinook salmon, steelhead trout, and other wildlife. This lawsuit claims toxic concentrations of the chemical have been discharged into waterways.
The U.S. Environmental Protection Agency (EPA) grants a petition submitted by multiple West Coast tr…
The U.S. Environmental Protection Agency (EPA) grants a petition submitted by multiple West Coast tribes to consider establishing regulations prohibiting the manufacturing of 6PPD in tires.
October 2023 — 1 developments
California's Department of Toxic Substances Control officially begins regulating 6PPD in motor vehicles through its Safer Consumer Products Program.
California's Department of Toxic Substances Control officially begins regulating 6PPD in motor vehicles through its Safer Consumer Products Program.
July 2023 — 1 developments
A study published in Environmental Science & Technology reveals that 6PPD-quinone disrupts the blood…
A study published in Environmental Science & Technology reveals that 6PPD-quinone disrupts the blood-brain barrier and other vascular systems in coho salmon, providing insight into its mechanism of toxicity.
March 2023 — 1 developments
The White House Office of Science and Technology Policy identifies 6PPD-Q as an emerging contaminant…
The White House Office of Science and Technology Policy identifies 6PPD-Q as an emerging contaminant, leading to the formation of a National Toxicology Program (NTP) work group to coordinate federal efforts, including human health effects.
January 2023 — 1 developments
The California Department of Toxic Substances Control (DTSC) announces plans to list 6PPD as a Prior…
The California Department of Toxic Substances Control (DTSC) announces plans to list 6PPD as a Priority Product, initiating a process for manufacturers to notify the state and explore alternatives.
January 2021 — 1 developments
Following the 2020 discovery, a widespread scientific investigation into 6PPD-quinone begins globally, with numerous reports appearing in scientific journals.
Following the 2020 discovery, a widespread scientific investigation into 6PPD-quinone begins globally, with numerous reports appearing in scientific journals.
December 2020 — 1 developments
Researchers from the University of Washington Tacoma, University of Washington, and Washington State…
Researchers from the University of Washington Tacoma, University of Washington, and Washington State University Puyallup publish a seminal study in Science, definitively identifying 6PPD-quinone (6PPD-Q) as the specific chemical responsible for coho salmon deaths.
January 2017 — 1 developments
Dr. Jenifer McIntyre's lab identifies tire wear particles as the toxic component in stormwater runof…
Dr. Jenifer McIntyre's lab identifies tire wear particles as the toxic component in stormwater runoff that causes salmon mortality, narrowing down the source of the problem.
January 1990 — 1 developments
Coho salmon deaths are first observed in urban streams of the Pacific Northwest, particularly after …
Coho salmon deaths are first observed in urban streams of the Pacific Northwest, particularly after rainfall, leading to the recognition of 'urban runoff mortality syndrome' with an unknown cause.