Estimating Personal Exposures Based on Mass Balance Material Usage Rates: Validation of a Ventilation Model in a Spray Paint Booth

Abstract

The goal of this research was to evaluate an estimating model (box model) with direct measurements of contaminants in an industrial spray painting operation. The research involved a dilution ventilation efficiency experiment that was devised to estimate the effective ventilation rate, sampling for organic compounds (xylene, ethyl benzene, methyl ethyl ketone, and methyl isobutyl ketone) in a paint booth, and simultaneously measuring the mass usage of these compounds during painting operations in order to compare measured with predicted concentrations. The results of the dilution ventilation experiment indicated that channeling of air was occurring due to a high ventilation rate in the painting area. The results of the mass balance usage and air sampling comparisons indicated that predicted concentrations were within the 95% upper/lower confidence interval about the geometric mean in 14 out of 16 area samples taken within the paint booth (87.5%). Correlation analysis between predicted concentrations and area, personal, and exhaust stack concentrations were strongest with exhaust (r = 0.923). Correlations with personal concentrations were not as strong (r = 0.828), and the area concentrations were even less strong (0.757). In conclusion, the box model does appear to be a useful additional tool for estimating worker exposures. However, the characteristics of any particular ventilation system must be understood before modeling is conducted.

Review and Evaluation of Different Paint Booths Depending on Their Air Flow

“…The downside is that if top priority is finish quality a downdraft will always have a cleaner paint finish because all overspray is pulled down away from the product while in a cross draft spray booth, overspray at the front of the spray booth can potentially land on your product at the back of the booth. Cross draft booth is not particarly adequate when painting multiple vehicles in the same booth, because overspray sits on objects further from air inlet [2].…”

“…These booths are also found in auto facilities, from manufacturing to repair centres. It is relatively cheap to install and maintain but provides lower finish quality [2]. Open face spray booth model [4] In reverse flow painting booth, the exhaust is located at the front near the drive-in doors and the fresh air enters through the rear wall (see Fig.…”