6PPD-Quinone (6PPD-Q) is a derivative of para-phenylenediamine (PPD), a preservative used in tire manufacturing to extend their useful life. These particles break down during tire wear and combines with oxygen in our environment to form 6PPD-Q. A team of researchers at the University of Washington discovered that this chemical is the cause of pre-spawn mortality in salmon as discussed in this article from The Conservancy Center, which means that the chemical in our local creeks will kill fish before they are able to lay eggs.
Watch this recent five minute video from King 5 with a great review of how 6PPD-Q was identified and what we are working to do about it now. The Department of Ecology posted a blog entry summarizing some of the resources and best management practices they have developed in the short time since this chemical was discovered.
Several best management practices for stormwater treatment and pollution prevention show promising results. 28 flow and treatment BMPs and 9 source control BMPs were rated as having high potential for removal 6PPD. Most of the high potential options involve dispersion, infiltration, or bioretention techniques. Further research is needed to understand the fate of the chemical and whether it would leach from soil back into the environment.
The California Department of Toxic Substances Control is considering adding PPD to the Candidate Chemicals (CC) List under section 69502.2 of the Safer Consumer Products (SCP) regulations. They held several public listening sessions on chemicals in motor vehicle tires. Comment periods are open on these topics! See more details and links to comment here.
The Pacific NW Chapter of the Society of Environmental Toxicology and Chemistry (PNW-SETAC) is collaborating with its West Coast colleagues, SoCAL SETAC and NoCAL SETAC, to present a seminar series on 6PPD Q titled Tire Wear Particles: Why We Need Them, What Risks They Pose, and What We’re Doing About It.
Here is a snapshot of the date, time, and speaker for each seminar in the series. Register here!