6PPD is the primary anti-degradant in tires and has been in use since the 1960s. 6PPD-quinone (6PPD-q) is one of the products formed by the reaction of 6PPD and ozone. 6PPD-q was identified as a chemical fatal to coho salmon in 2020. Since that time, it has been documented as acutely toxic to multiple trout species found throughout the United States. 6PPD and 6PPD-q have been found in waterways, aquatic organisms, soil, air, and humans.
The 6PPD & 6PPD-quinone (6PPD, 2024) guidance document provides information about 6PPD and 6PPD-q to help inform future policies and regulations related to these chemicals. It includes an introduction to 6PPD and 6PPD-q, current knowledge on their effects, toxicity, and physical and chemical properties, and information on their occurrence, fate, and transport in the environment. The guidance also covers approaches for measuring, mapping, and modeling these chemicals, as well as mitigation measures, solutions, policies, regulations, and laws. In addition, it highlights key information gaps and research needs, and the 6PPD Team also developed a companion focus sheet, What We Know: 6PPD and 6PPD-quinone, which provides a high-level overview of the topic.
Topic(s): 6PPD, Contaminants of Emerging Concern, Stormwater, Tire Degradant
