Study Reveals Brake Pad Dust Is More Harmful Than Diesel Emissions | Carscoops

      The transition to electric vehicles (EVs) will not eliminate all airborne pollutants from cars, and emissions from brakes are not yet regulated in the same way as tailpipe emissions.

      Researchers have expressed worries about harmful emissions from brake pads. A recent study indicates that brake emissions could be more detrimental than diesel exhaust. Even electric vehicles contribute to pollution through their braking systems, despite utilizing regenerative braking technology.

      While many proponents view electric cars as essential for combating climate change and improving air quality, new findings suggest that brake dust from both EVs and internal combustion engine (ICE) vehicles may be so toxic that it is more harmful than inhaling diesel fumes.

      This might be unexpected given that EVs primarily use regenerative braking, reducing reliance on traditional friction brakes. Nonetheless, electric cars are significantly heavier than their non-plug-in hybrid counterparts, which results in greater dust generation when they do use their brakes.

      A study conducted by scientists at the University of Southampton in the UK examined the impact of particulate emissions from various types of brake pads on lung health. Among the pads studied, one had a low metallic composition, while the other three were semi-metallic, non-asbestos organic, and hybrid ceramic.

      Typically, items labeled as organic are perceived as healthier, but tests revealed that non-asbestos organic pads caused the most lung inflammation, proving to be more toxic than diesel emissions. The authors of the study note that these types of pads are prevalent in the US due to their affordability, quiet operation, and relatively low wear rates.

      Although EVs do not release tailpipe emissions, they do produce brake dust particles. The newer pads, which replace older asbestos-containing versions, are made with copper fibers to enhance thermal conductivity, a property previously attributed to asbestos. Asbestos was phased out due to its association with lung diseases, but the copper dust from modern pads has also been linked to health issues like cancer, asthma, and chronic pulmonary disease.

      Regulations are being developed, albeit slowly. California and Washington have enacted laws aimed at reducing copper content in brake pads, but these laws focus more on preventing runoff and protecting aquatic ecosystems rather than safeguarding human health. Additionally, the upcoming Euro 7 emissions regulations, effective in 2026, will impose some limitations on brake dust emissions, although they will likely apply only to new vehicles and not existing parts.

      Currently, there is limited regulation worldwide governing non-tailpipe emissions from vehicles, including those from tires, which are another significant source of harmful particles. While EVs do utilize regenerative braking, they also employ traditional friction brakes, leading to brake dust generation, and their heavier weight compared to ICE vehicles results in increased tire pollution.