USTMA warns against ‘premature’ restrictions on 6PPD in tires

Washington - The US Tire Manufacturers Association (USTMA) has warned that any “premature” prohibition on the use of 6-para-phenylene-diamine (6PPD) in tires could be "detrimental to public safety". 

The association was responding to recent moves by the US Environmental Protection Agency (EPA) to initiate a risk-management proceeding for 6PPD, under the Toxic Substances Control Act (TSCA).

This followed recent discoveries linking the tire anti-degradant to marine toxicity: EPA now seeking “technically and economically feasible alternatives [to 6PPD] that benefit health or the environment.”

In a statement 3 Nov, USTMA said the association and its members “have been working closely” with federal and state regulators as well as other stakeholders to evaluate alternatives to 6PPD since 2020.

“USTMA looks forward to continuing this effort by working with EPA to identify an alternative to 6PPD and to implement it on a time-frame consistent with public safety,” it added.

The chemical substance in tires helps prevent the degradation and cracking of rubber compounds caused by exposure to oxygen, ozone, temperature fluctuation, and flexing induced fatigue.

USTMA emphasised that protection materials, such as 6PPD, are “essential” for tire performance and safety, adding that any potential alternative “must continue to ensure compliance” with US vehicle safety standards and other requirements.

“It is not a simple process to change the composition of tires; any change could affect the stopping distance of tires, durability, vehicle fuel economy, tire wear and other safety?related components,” it noted.

USTMA said it would coordinate closely with EPA to provide appropriate information about the performance, safety, and environmental characteristics of 6PPD, 6PPD-Quinone, and potential alternatives to 6PPD.

“While many potential alternatives are being considered, none has been demonstrated to be technically feasible for meeting federal safety requirements,” said USTMA.

Any “premature prohibition on the use of 6PPD in tires”, concluded the association, would be “detrimental to public safety and the national economy”.