WASHINGTON—The tire manufacturing additive 6ppd, an antioxidant and antiozonant essential to passenger safety and harmful to coho salmon when transformed into 6pp-quinone, has been elevated in priority as a substance to be studied.
This was due, in part, to the efforts of the U.S. Tire Manufacturers Association, which on May 23 endorsed a same-day decision by the California Department of Toxic Substances Control to list 6ppd as a "priority product" under the Safer Consumer Products Regulations.
"USTMA supports the decision by the California DTSC to list 6ppd as a priority product under the state's green chemistry program," said USTMA President and CEO Anne Forristall Luke. "We are fully committed to continuing to work with the DTSC team to find a viable alternative."
The USTMA has been partnering with the University of Washington since 2019 on the study of urban runoff mortality syndrome, the technical name for what is affecting the coho salmon, according to a report from Nov. 17, 2021.
Ultimately, a study by Tian et. al known as "A ubiquitous tire rubber–derived chemical induces acute mortality in coho salmon" was published in December 2020, drawing a scientific link between 6ppd-quinone and coho salmon (and possibly other aquatic species') mortality rates.