The US Tire Manufacturers Association’s (USTMA) 6PPD Alternatives Analysis Consortium has received a Notice of Compliance from the California Department of Toxic Substances Control (DTSC) for its revised Preliminary (Stage 1) Alternatives Analysis report. This compliance allows the Consortium to move forward with developing a Stage 2 Alternatives Analysis report, to further explore the most promising potential replacements for 6PPD in motor vehicle tires.
The California DTSC recognized the Consortium’s “continued efforts to seek safer alternatives to 6PPD” and acknowledged USTMA’s “open communication about research updates and results.” USTMA had initially requested that 6PPD be added to the agency’s priority products plan in December 2020. 6PPD is a chemical that prevents automotive tires from degrading and helps them last longer. On exposure to air, 6PPD reacts with ozone to create 6PPD-quinone, which is toxic to fish and poses an ecological risk.
The Consortium originally submitted its preliminary report in March 2024, examining over 60 initial candidates as potential alternatives to 6PPD in tires. Following a Notice of Deficiency from California DTSC, a revised Stage 1 report was submitted in July, addressing the agency’s suggestions and requests for clarification, which are standard in the alternatives analysis process.
The revised report identified seven potential alternatives to 6PPD that will undergo further investigation in the upcoming Stage 2 Analysis. USTMA says it is hopeful that by the conclusion of the analysis, one or more viable alternatives will be found to either replace or significantly reduce the use of 6PPD in motor vehicle tires, pending further safety and performance testing.
“USTMA and the Consortium deeply appreciate the collaboration with California DTSC to produce the most thorough possible Stage 1 report on potential 6PPD alternatives,” said USTMA president and CEO Anne Forristall Luke. “We look forward to producing a similarly rigorous Stage 2 report and continuing additional work on identifying viable 6PPD alternatives.”
The Consortium’s Stage 2 report is due to DTSC on August 19, 2026, with an annual progress report due on August 19, 2025. The Consortium includes 32 global tire manufacturers, encompassing all of USTMA’s member companies.
