Jump to Content
Juvenile coho salmon swimming in shallow water.

Photo Credit: Roger Tabor

press release

Feds to investigate tire chemical implicated in mass salmon deaths, but urgent action needed, environmental groups react

May 7, 2024

VANCOUVER/UNCEDED xʷməθkʷəy̓əm (MUSQUEAM), Sḵwx̱wú7mesh (SQUAMISH) AND səlilwətaɬ (TSLEIL-WAUTUTH) TERRITORIES – Environmental groups are encouraged by the federal government’s decision to grant their request to prioritize the tire chemical 6PPD for assessment, an important first step towards regulating this toxic chemical.   

In February, Ecojustice, on behalf of Raincoast Conservation Foundation, Watershed Watch Salmon Society, and Pacific Salmon Foundation, formally requested the federal government assess the harms caused by 6PPD, a chemical linked to mass die-offs of coho salmon. 

Prioritizing 6PPD for assessment under the Canadian Environmental Protection Act (CEPA) is a crucial step to ensuring 6PPD is regulated and coho salmon are protected. Environment and Climate Change Canada has committed to releasing their plan to prioritize assessments by June 2025, and a regulatory intervention – should it proceed – would occur at a future date to be determined. While there is no set timeline for regulatory intervention under CEPA, an expedited assessment is strongly needed to protect salmon.

6PPD is an additive that manufacturers use to prevent tires from degrading. Over time, tires release particles and chemicals that enter waterways.  The breakdown product of 6PPD, called 6PPD-quinone (6PPD-q), has been linked to mass deaths of coho salmon when they pass through urban streams. An estimated 40-90 percent of adult coho salmon returning to spawn in urbanized watersheds could die from exposure to this chemical each year. Since a seminal study in December 2020 first identified 6PPD-q as the cause of coho deaths in Washington State, similar impacts are being observed in other fish, including rainbow trout and lake trout. The full scope of harm is unclear, but the lethal effects of 6PPD-q requires urgent action and government regulation. 

Daniel Cheater, Ecojustice lawyer:  

“We commend the government for taking appropriate action and granting our request to prioritize 6PPD for assessment. It is now critical that this toxic chemical be assessed as soon as possible.  

“The longer this process takes, the longer 6PPD will cause mass die-offs of this keystone species. Coho salmon need swift action to ensure they are given a fighting chance.”   

 Dr. Peter S. Ross, Senior Scientist at Raincoast:

“Getting 6-PPD out of vehicle tires is critically important and time sensitive if we are to stop the mass die-offs of coho salmon as they head upstream to spawn. The Minister’s decision to prioritize regulatory scrutiny of this acutely toxic chemical is an important step forward, but we need to accelerate regulatory intervention. Without prompt action, tires will continue to release 6PPD and its breakdown product 6-PPD-q into fish habitat and kill salmon for years to come.”

Lina Azeez, Habitat Programs Director at Watershed Watch Salmon Society

“The federal government has an opportunity  to do the right thing. We hope they act quickly to ban a substance known to be deadly to salmon and other fish. Doing so will showcase strong environmental leadership, something we all desperately need the government to step up to and be a leader in right now.”

Michael Meneer, President & CEO, Pacific Salmon Foundation: 

“On behalf of the Pacific Salmon Foundation, I thank the Minister of Environment and Climate Change Canada for making the decision to review 6PPD and 6PPDQ, a critical first step in protecting our wild salmon from this tire chemical known to kill coho salmon. I recently attended a meeting with a network of 120 community and First Nations partners who have been monitoring this chemical and its impact on salmon survival for years and are actively looking at solutions to mitigate its impacts. This decision is an important first step to protect Pacific salmon and our environment from this toxic chemical.”

 Background information 

  • This is the first time the Section 76 amendment to the CEPA legislation has been used to successfully request prioritization. It is also the first time Canada has taken action to address 6PPD.
  • When 6PPD comes into contact with ozone in the air it turns into 6PPD-quinone (6PPD-q), highly toxic to coho salmon. While the source of mass coho deaths in urban areas was unknown for decades, a seminal 2020 study confirmed 6PPD-q as the cause
  • Through tire wear on roadways, 6PPD particles make their way into urban rivers and streams through rain run-off, turning waterways toxic.    
  • 6PPD has also been found in sediments and soils, household dust and human urine.