Inventories, risk characteristics and management recommendations for emerging pollutants in vehicles

By comparing the relevant control inventories, 55 potential emerging pollutants across 20 vehicle categories were identified. Among various materials, plastic components were found to contain the most types of these pollutants, followed by rubber, coatings, and textiles. The most widespread emerging pollutants across materials are phthalates (PAEs), followed by perfluoroalkyl and polyfluoroalkyl substances (PFASs), chlorinated paraffin (CPs), nonylphenols (NPs), and polycyclic aromatic hydrocarbons (PAHs). Risk characteristic analysis revealed that the carcinogenic risk from Bis(α-ethylhexyl) phthalate (DEHP) in vehicle indoor air has the highest value at 9.45 × 10⁻⁷, which is below the U.S. Environmental Protection Agency (EPA) threshold of 1×10⁻⁶. The non-carcinogenic risk of Pentadecafluorooctanoic acid (PFOA) has the highest value at 0.11, again lower than the EPA's threshold value of 1. A comparative analysis of domestic and international regulations on hazardous substances in vehicles highlighted the shortcomings of relevant Chinese laws and regulations. Some suggestions were finally provided, including conducting further research into alternative technologies, developing a standard system for unintentional trace emerging pollutants, formulating guidelines for emerging pollutants control in the vehicle industry, and establishing a detection index system for these pollutants in vehicles.