CONTROL OF PAINT OVERSPRAY IN AUTOBODY REPAIR SHOPS

Commercially available controls for reducing worker exposure to paint overspray were evaluated in six autobody shops and a spray-painting eq uipment manufacturer's test facility. Engineering control measures inc luded spray-painting booths, vehicle preparation stations, and spray-p ainting guns. The controls were evaluated by measuring particulate ove rspray concentrations in the worker's breathing zone, visualizing the airflow in spray-painting booths and vehicle preparation stations, and measuring airflow volumes and velocities, In addition, respirator usa ge observations were collected at five of the autobody repair shops, a nd quantitative fit tests were conducted on existing respirators at th ree shops. Several conclusions were drawn from this study. Downdraft s pray-painting booths provide lower particulate overspray concentration s measured on the worker than crossdraft and semidowndraft spray-paint ing booths. In the latter two booths, the spray-painting gun can dispe rse as much as half the paint overspray into the incoming fresh air, i ncreasing worker overspray exposure. Vehicle preparation stations have no walls to contain the overspray and, commonly, a single exhaust fan removes air from the painting area. Airflow patterns suggest that the se do nor control the paint overspray, Switching from a conventional s pray-painting gull to a high-volume low pressure spray-painting gun re duced the particulate overspray concentration by a factor of 2 at a ma nufacturer's test facility. However, this change did not significantly affect solvent concentrations. Finally, respirator usage in five of t he six shops studied was inappropriate. Respirators were poorly mainta ined and/or did not fit the workers, perhaps due to the absence of a f ormal respirator program.