Toxic Tire Chemical That Kills Salmon Comes Under Federal Scrutiny

A chemical compound found in many car tires is coming under scrutiny after west coast tribes claimed it is killing salmon populations across America. Federal regulators will launch a probe into a preservative used in most car tires as it can be toxic to many species of fish when rainwater washes it into rivers and streams.

2023 Range Rover Sport | Quick Drive

Many tires sold across America contain a compound called 6PPD, which is a rubber preservative that helps prevent tires from cracking and degrading too quickly. However, the compound reacts with the air in our atmosphere to create a toxic substance that is threatening the safety of streams and rivers across America.

Now, federal regulators are considering launching an investigation into the use of 6PPD in tires sold across America, reports the Associated Press. The investigation has been called for after scientists discovered a link between the use of the compound and a condition called “urban runoff mortality syndrome” that kills coho salmon populations and affects other native fish like rainbow trout, arctic char and white sturgeon. The AP reports:

The Yurok tribe in California and the Port Gamble S’Klallam and Puyallup tribes in Washington asked the Environmental Protection Agency to prohibit the rubber preservative 6PPD earlier this year, saying it kills fish — especially coho salmon — when rains wash it from roadways into rivers. Washington, Oregon, Vermont, Rhode Island and Connecticut also wrote the EPA, citing the chemical’s “unreasonable threat” to their waters and fisheries.

“We could not sit idle while 6PPD kills the fish that sustain us,” Joseph L. James, chairperson of the Yurok Tribe, told The Associated Press. “This lethal toxin has no business in any salmon-bearing watershed.”

The EPA’s decision to review the use of 6PPD in tires is the first step in the long process that could result in it being banned from tires sold across America. But despite the process for its banning being a long one, the AP reports that tire manufacturers are already “looking for an alternative that still meets federal safety requirements.”

Chemicals released by the tires are harming coho salmon populations. Photo: Gabrielle Lurie/San Francisco Chronicle (Getty Images)

While the chemical is used in many different rubber products, including shoes and playground equipment, its use in car tires is the most damaging to wildlife. That’s because as a car drives along a road, tiny particles of rubber are kicked off as the tire rubs against the tarmac.

The 6PPD that’s found in these particulates can then break down into a toxic compound called 6PPD-quinone, which is water soluble so can be washed into rivers and streams when rain falls. Once in the waterways, 6PPD-quinone can kill coho salmon “in hours,” according to the west coast tribes.

But the tribes aren’t the first people to alert lawmakers to the dangers of this compound to fish stocks in America. In 2020, scientists in Washington state published a paper investigating the impact of tire wear on American fish populations. They found that 6PPD-quinone could kill come fish species in as little as 70 minutes.