 Workers in auto body repair shops are exposed to hazardous chemicals during spray painting and vehicle repair. As an owner of an auto body repair shop, it is important to know how to protect your workers from these substances. If you are an auto body repair worker, you need to know how to protect yourself and use the safety equipment provided to you. In a major study of auto body repair shops, NIOSH researchers found effective methods to protect workers from excess exposures to airborne chemicals. These control techniques include ventilated sanders, engineering controls during spray painting, and proper use of respirators. During auto body repair, sanding is performed to remove paint and to smooth body panels repaired with body-filling compounds. Workers may be exposed to total airborne dust concentrations exceeding the OSHA standard. In addition, the dust from sanding may contain toxic metals such as lead and chromium. Rotary orbital and straight-line reciprocating sanders equipped with high-velocity, low-volume HV-LV ventilation as part of the tool's design can reduce dust concentrations during the sanding of body-filling compounds. Air is exhausted through holes in the sanding pads and sandpaper. At one auto body shop, NIOSH showed that the HV-LV ventilated sanders reduced dust concentrations by a factor of 10 compared to unventilated sanders. In this shop, workers preferred using the HV-LV sanders and found the ventilated sanders resulted in a cleaner shop. Spray painting eventually results in exposure to paint overspray. Paint overspray contains solvents, metal pigments, and polyisocyanates. Exposure to these substances may cause symptoms such as nervous disorders, skin and eye irritation, respiratory sensitization, and asthma. Effective control of worker exposure to paint overspray requires proper selection of spray-painting guns, a correctly designed and ventilated spray-painting booth, and personal protective equipment. High-volume low-pressure spray-painting guns are recommended instead of conventional gravity or siphon-feed spray-painting guns. NIOSH researchers showed the high-volume low-pressure spray-painting guns reduced particulate overspray concentrations by a factor of 2 compared to conventional guns. Down-draft spray-painting booths were compared with cross-draft booths and semi-down-draft booths. These types of booths are illustrated here. The down-draft booth is recommended because it results in lower concentrations of paint overspray. The down-draft booth must be designed for the correct amount of air flow into the booth and out of the booth. The booth must also be maintained properly. At one auto-body shop studied, the exhaust louvers were partially plugged with paint overspray, but when cleaned, the air flow doubled. At another auto-body shop, the booth poorly controlled paint overspray because there were no exhaust filters in the floor of the booth. Although the engineering controls just described will greatly reduce paint overspray concentrations, they will not completely eliminate overexposure to paint spray. Therefore, personal respiratory protective equipment is recommended. This requires that the auto-body shop have a respiratory protection program containing all the elements in the OSHA standard. OSHA requires that each worker be tested while wearing a respirator to ensure that the respirator provides adequate protection. The auto-body shop must also provide workers with the type of respirator appropriate for the hazard, and the respirators must be maintained. As part of their study, NIOSH conducted quantitative fit tests on respirators, that is, how much leakage is there around the mask. These tests revealed that many of the respirators worn during spray painting did not provide the worker with adequate protection. Most of the respirators tested were in poor condition and were poorly maintained. A review of OSHA citations for auto-body repair shops showed that violations of the OSHA respirator standard was the second most common violation. Along with a well-maintained down-draft spray painting booth, a formal respirator program involving training and maintenance is needed to protect workers from the hazards of paint overspray. In summary, the use of ventilated sanders in collision repair shops can provide a large reduction in worker dust exposures. Workers can be protected from paint overspray by one, using high-volume, low-pressure spray painting guns, and two, working in a down-draft ventilation spray booth that has sufficient air movement. Nearly all auto-body spray painting shops will also need a respirator program to protect workers from paint overspray. Any respirator program must follow the OSHA respirator standard.