California Air Resources Board

Thank you for the opportunity to provide commentary on the California Drive Forward Light-duty Vehicle Program following the public workshop on June 22, 2026. I am writing on behalf of the SAE International Brake Materials Environmental Task Force regarding the inclusion of brake particulate emissions in upcoming regulatory activity.
Brake particulate emissions is an incredibly complex attribute to measure and characterize, especially considering the proliferation of advanced electrified powertrains in modern vehicles. As such, the vehicle braking industry at large is interested in contributing technical and scientific input during CARB’s rulemaking process. Several members of the task force have direct experience in the recent European Union activities around UN-R179, UN GTR24, and EURO7.
The SAE Brake Materials Task Force has served as an intermediary function in the past, partnering with industry technical representatives, regulatory agencies, and industry advocate groups to ensure the smooth implementation of new environmental regulations. This task force is committed to provide independent technical expertise, engineering data, and advisory support, and serves as a liaison to other SAE committees. The most recent example has been the work with California Dept. of Toxic Substances Control on the phase out of copper and heavy metals from brake pad friction material starting in 2021. This SAE task force would like to extend an invitation to relevant stakeholders at CARB for technical discussions on this topic in our future task force meetings.
If there are any questions on the function of the task force, or to engage in further collaboration, please reach out at any time. This task force looks forward to the opportunity to provide more technical input in the future.

Thank you for the consideration of these comments from the SAE International Brake Materials Task Force.