Criteria pollutant impacts of volatile chemical products informed by near-field modelling

Consumer, industrial and commercial product use is a source of exposure to potentially hazardous chemicals. In addition, cleaning agents, personal care products, coatings and other volatile chemical products (VCPs) evaporate and react in the atmosphere, producing secondary pollutants. Here, we show that high air emissions from VCP use (≥14 kg per person per yr, at least 1.7× higher than current operational estimates) are supported by multiple estimation methods and constraints imposed by ambient levels of ozone, hydroxyl radical reactivity and the organic component of fine particulate matter (PM2.5) in Pasadena, California. A near-field model, which estimates human chemical exposure during or in the vicinity of product use, indicates that these high air emissions are consistent with organic product use up to ~75 kg per person per yr, and the inhalation of consumer products could be a non-negligible exposure pathway. After the PM2.5 yield is constrained to 5% by mass, VCPs produce ~41% of the photochemical organic PM2.5 (1.1 ± 0.3 μg m−3) and ~17% of the maximum daily 8 hr average ozone (9 ± 2 ppb) in summer in Los Angeles. Therefore, both toxicity and ambient criteria pollutant formation should be considered when organic substituents are developed for VCPs in pursuit of safer and more sustainable products and cleaner air.