Maximum exposure levels for xylene, formaldehyde and acetaldehyde in cars

Although millions of individuals are exposed to emissions from articles inside cars, relatively little has been published about possible adverse health effects and about exposure levels that can be considered safe or “acceptable”. Xylene, formaldehyde and acetaldehyde represent typical examples of relevant volatile organic substances (VOC) released from articles inside cars. Recently, a concept for derivation of maximum exposure levels for volatile organic substances in cars has been published. In the present study we applied this concept to derive maximum exposure levels for xylene, formaldehyde and acetaldehyde and compared the resulting concentrations to exposure levels usually found inside of cars. We derived Short Term Exposure Levels Inside Automotive Vehicles (STELIA) of 29, 0.125 and 15.3 mg/m3 for xylene, formaldehyde and acetaldehyde, respectively. These STELIAs should not be exceeded during short-term exposures, for instance when starting a car that had been heated up during parking in the sun. Exposure Levels Inside Automotive Vehicles (ELIA, chronic) for chronic exposure to non-genotoxic substances were 8.8, 0.125 and 0.635 mg/m3 for systemic as well as 17.6, 0.125 and 1.7 mg/m3 for local exposure to xylene, formaldehyde and acetaldehyde, respectively. Although, it is known that exposure limits for carcinogenic substances should be treated with caution, encouraged by the well documented threshold mechanisms we nevertheless derived ELIAs for Carcinogenic and Mutagenic Substances (ELIA, cm) resulting in 0.125 and 0.635 mg/m3 for formaldehyde and acetaldehyde. If these ELIAs are matched against average concentrations of xylene, formaldehyde and acetaldehyde found in cars at 23 °C (1.22, 0.048 and 0.042 mg/m3), there is no reason for concern. With respect to STELIAs and extrapolated concentrations at 65 °C (14.7, 1.47 and 1.68 mg/m3, for xylene, formaldehyde and acetaldehyde, respectively), however, a reduction of the concentration of formaldehyde may be necessary.