What is 6-PPD Quinone

T6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine), a chemical used in vehicle tires to prevent degradation from ozone and other reactive oxygen species, transforms into 6PPD-Quinone (6PPD-Q) upon exposure to ozone. As tires wear down through road contact, they release particles containing 6PPD and its byproducts into the environment. During rainfall, stormwater runoff from roads, parking lots, and other hard surfaces transports these particles into streams and water bodies. As a result, 6PPD-Q accumulates in aquatic environments, posing a significant threat to aquatic organisms.

Research shows 6PPD-Q is toxic to many aquatic organisms throughout the food chain and can impair wildlife survival. 6PPD-quinone is acutely toxic to Coho salmon and kills fish within a few hours after exposure. While little is known about the effect of 6PPD-quinone on other organisms, 6PPD-quinone is also acutely lethal to other related fish species found in California, including brook trout, steelhead/rainbow trout, and, to a much lesser degree, Chinook salmon.

Due to recent discovery of 6PPD-Q, scientists are still learning about this chemical and its impact on the environment. Current efforts for mitigation include monitoring and testing, reducing stormwater runoff, and manufacturing tires with alternate additives.