Evaluation of individual exposure to organic solvents using a portable VOC monitor]

Analysis by gas chromatograph after collection of personal samples is the most common method of evaluating individuals' exposures to organic solvents. This method provides us time-weighted averages (TWA) only, and does not measure fluctuating concentrations of organic solvents. A portable VOC monitor is widely used as a rapid screening instrument for volatile organic compounds (VOCs) in houses, schools, etc. The VOC monitor equipped with a photoionization detector can measure real-time concentrations of VOCs. In this study, the author investigated whether the VOC monitor can evaluate individuals' exposures to organic solvents. First, standard organic solvent gases were prepared and the gas concentrations were measured by a passive air sampler and the VOC monitor. Correction factors (CF) were obtained for the response of the isobutylene calibrated VOC monitor to equal concentrations of the organic solvents. Methyl ethyl ketone's CF was 0.5952, toluene's CF was 0.4418, and N,N-dimethylformamide's CF was 0.9017. Then, a mixed standard organic solvents gas was prepared and the gas concentration was measured by both methods. A significant correlation between both methods was obtained (p < 0.001). Subsequently, 37 male workers in a synthetic-leather factory were examined for solvent exposure using both the VOC and a passive sampler, Similar results were obtained by both methods (p < 0.001). Real-time data can be obtained using the VOC monitor and high exposure tasks can be identified. The VOC monitor will be useful for reducing occupational exposure. Since the VOC monitor provides detailed data of individuals' exposures to organic solvents.