Exposure characterization of aerosols and carbon monoxide from supplemental inflatable restraint (automotive air bag) systems

Abstract The purpose of this study is to determine the characteristics of aerosols inside a passenger car after the deployment of air bags (supplemental inflatable restraints, SIR) for a worst-case situation. Mass concentrations and size distributions of the SIR-aerosols, and the concentration of carbon monoxide were measured. The average total particulate mass concentrations during each of the 25-min observation periods immediately following deployment of three different preproduction SIR-systems, each employing three inflators were 86, 83 and 415 mg m −3 , and the average carbon monoxide concentrations were 46, 48 and 180 ppm, respectively. The SIR-aerosols exhibited bimodal size distributions with modes centred at 0.8 and 10 μm. Using ion chromatography, the fine aerosol fraction near 1 μm was found to contain carbonates, while the larger aerosol near 10 μm was not alkaline and was probably derived from corn starch, a dry lubricant which coated the air bag. Currently, very limited human exposure data exist which can be used to assess the respiratory effects from a single acute exposure to such dusts. The absence of short-term exposure limits for workplace aerosols or nuisance dusts with similar properties warrants studies to quantify the human respiratory response to SIR-aerosols.