Iconic Coho salmon are dying in record numbers. A mysterious killer in our water has finally been unmasked.

Tires use a chemical called 6PPD to prevent cracking. But when it hits the air, it transforms into something deadly.

Rain washes tire dust containing 6PPD-quinone into storm drains and directly into sensitive salmon habitats.

6PPD-quinone is so toxic that just a few parts per trillion can kill a salmon in mere hours.

For decades, scientists called it 'Urban Runoff Mortality Syndrome.' Now, the tire link is undeniable.

Tribes in the Pacific Northwest petitioned the EPA to ban 6PPD, citing treaty rights and ecological devastation.

In 2026, a federal trial in San Francisco challenged major tire makers over Endangered Species Act violations.

Washington lawmakers introduced a bill to ban 6PPD by 2035, forcing the industry to find safer alternatives.

Tire makers argue 6PPD is vital for safety and that no 'drop-in' replacement currently exists.

Rain gardens and bio-swales can filter out 6PPD-quinone, buying time for the salmon while tires evolve.

The battle to ban this killer chemical is more than just about tires—it's about the survival of an entire species.