Saving coho salmon: Alternatives for 6PPD in tire manufacturing
In early 2021, 6PPD-quinone, which is a transformation product of 6PPD, was discovered as the likely cause of pre-spawn mortality in Coho salmon in the Pacific Northwest. 6PPD is a critical tire rubber additive with high-performing antidegradant properties. The team proposed four strategies: the use of food preservatives, such as gallates; replacement with the polymer lignin; modification of 6PPD to prevent formation of its toxic quinone form; and finally, broader process-level changes, including adjustments to vulcanization processes schemes and rubber formulation.