Development of a personal passive air sampler for estimating exposure toeffective chlorine while usingchlorine-based disinfectants.

With an increasing use of indoor disinfectants such as chlorine (Cl2 ) and hypochlorous acid (HOCl), a convenient sampler for estimating exposure to oxidants, such as effective chlorine, is necessary. Here, we developed a personal passive air sampler (PPAS) composed of a redox dye,o-dianisidine, in a polydimethylsiloxane(PDMS) sheet. o-Dianisidine readily reacts with gaseous oxidants generated by bleach usage, and its colorchanges as the reaction progresses; hence, personal exposure to effective chlorinecould be easily detected by the naked eye,while cumulative exposure could be determined by measuring concentrations of o-dianisidine reacting with it. The PPAS was calibrated,and asamplingrate of 0.00253 m3 h-1 was obtained using a small testchamber. The PPAS was tested with the help of ten volunteers whosepersonal exposure toCl2 -equivalent gas was estimated after bathrooms were cleaned using spray and liquid-type household disinfection products, and the accumulated exposure-gas concentrations ranged from 69 to 408 ppbv and 148 to 435 ppbv, respectively. These PPAS-derived exposure concentrations were approximatelytwoorders lower than those estimated using ConsExpoTM , suggesting a significant overestimation by prevailing screeningmodels,possibly due to the ignorance of transformation reactions.