The US Tire Manufacturers Association (USTMA), the sister organization to the Tire and Rubber Association of Canada (TRAC), has recently announced that it supports the proposed rulemaking released by the California Department of Toxic Substances Control (DTSC) to designate 6PPD in automobile tires as a priority product for review under the state’s Safer Consumer Products green chemistry program.

What is 6PPD?

6PPD is an antioxidant and antiozonant that helps prevent the degradation and cracking of rubber compounds caused by exposure to oxygen, ozone, and temperature fluctuation. 6PPD is used industry-wide to help tires resist degradation and cracking, which is vital for driver and passenger safety. Antioxidants support increased tire endurance. Read More

Why is this important?

USTMA and its member companies recommended adding 6PPD to the Priority Products Work Plan immediately following the December 2020 Tian et al. study that suggested a link between Coho salmon mortality and a transformation product of 6PPD from tire and road wear particles (TRWP) called 6PPD-Quinone. Tire manufacturers have taken seriously the Tian et al. study and more recent scientific findings which indicate that 6PPD-Quinone, a previously unknown transformation product of 6PPD – an essential antioxidant and antiozonant used in tires – has contributed to the mortality of coho salmon and potentially poses risks to other aquatic species in the Pacific Northwest.

What is USTMA doing to support this?

Since the release of the Tian et al. study 18 months ago, USTMA has worked with researchers, regulators, and legislators to more fully understand the implications of these findings and to seek solutions, including filling research gaps around 6PPD-Quinone; advocating for a 6PPD alternatives analysis in California; and supporting mitigation efforts to treat stormwater runoff.

As global leaders in manufacturing, USTMA member companies embrace a shared responsibility of helping to achieve a more sustainable society. Tire manufacturers are dedicated to understanding and reducing the environmental impact of their products. USTMA members — both individually and through partnerships — are working to incorporate more renewable and recycled materials into tires, enhancing biodiversity and reducing dependence on non-renewable feedstocks.

To learn more, please visit this page.