Global tire consortium identifies five potential 6PPD alternatives

Washington – A global consortium of 30 tire manufacturers has identified five potential alternatives to 6PPD as an anti-degradant for tires.

Mobilised by the US Tire Manufacturers Association (USTMA), the consortium members have submitted a 'stage 1' alternative analysis report on potential 6PPD replacements.

The report establishes the basis for further evaluation of possible alternatives in stage 2, which will result in a final alternatives analysis report, USTMA said 29 March.

As part of the assessment process, over 60 candidate alternatives for 6PPD were evaluated, screened and scored for likely feasibility.

The research was based on a new screening method developed by the consortium specifically for the study, according to the USTMA.

In total, 40 possible alternatives were identified and then subjected to a detailed approval analysis process in accordance with ‘California’s safer consumer product regulations’.

After reviewing the potential hazards, physical chemical properties and initial performance data for the 40 chemicals, the consortium identified five that warranted further evaluation.

USTMA partnered with Gradient, a specialist in the alternatives analysis field, to conduct the Stage 1 AA.

The report is particularly notable for the “large and diverse” number of candidate alternatives identified and screened, according to Gradient project lead Dr Tom Lewandowski.

A “robust approach” was applied to considering potential impacts of possible alternatives across the entire product lifecycle,” Lewandowski added.

The chemicals selected for further evaluation in stage 2 had "sufficient data demonstrating suitable potential in the areas of performance and environmental impact,” said USTMA.

During stage 2, the consortium will confirm a short list of possible alternatives and assess the potential impacts of these options.

The project will also initiate “a more detailed review” of the chemicals’ potential hazards and exposure-related chemical properties.

According to USTMA, 6PPD is “exceptional” in terms of ensuring tire and passenger safety and has been used for decades.

The rubber chemical serves an essential safety function, protecting the components of the tire from attack by ozone and oxygen.

However, over the recent years, a number of researches have raised environmental concerns over a 6PPD transformation product, 6PPD-quinone (6PPDQ), that can impact aquatic life, particularly salmon.

“The safety, performance and sustainability of our products remains our uncompromising priority,” said USTMA president and CEO Anne Forristall Luke.

As a result, noted the association leader, “there is important work to be done to ensure any potential alternatives meet that high standard.”