Engineering Controls Database

Autobody Repair Shops – Control of Paint Overspray

When painting during auto body repair, multiple thin layers of the different paints are applied. When base metal is exposed, these areas are first covered with a primer. Once the vehicle is ready for final painting, several base coats are applied, the paint is allowed to sit a short while (10-20 minutes), then the color paint is applied, again in several thin coats. Lastly, the clear top coat is sprayed on until a uniform gloss is achieved. The vehicle is then allowed to sit overnight or in a heated booth to allow the paint to dry.

High volume, low pressure (HVLP) spray guns are used to reduce the amount of paint over-spray. However, many painters still use conventional spray gun to some degree, especially when applying the clear coats of paint. Even if a spray booth is available at the repair shop, paint may be applied in a secondary temporary booth or in the open. This is due to the number of cars being painted and the limitations on drying times.
Hazardous components of paint spray include metals such as lead and chromium, polyisocyanates, and liquid organic solvents. Autobody workers may develop nervous disorders, skin and eye irritation, respiratory sensitization, asthma and reduced lung function from exposure to paint.
Effective control of worker exposure to paint overspray requires the proper selection of spray painting equipment, a properly designed and ventilated spray painting booth, and personal protective equipment. Formal training and maintenance programs will help ensure that all equipment operates properly. Three types of control are recommended:

Spray Painting Guns

HIGH VOLUME, LOW PRESSURE (HVLP) spray painting guns are recommended instead of conventional gravity or siphon-feed spray painting guns because HVLP guns cut paint overspray concentrations in half. HVLP guns transfer paint more efficiently and can reduce paint usage.

Paint Booth Ventilation

DOWNDRAFT VENTILATION spray painting booths are recommended instead of Crossdraft or Semi-Downdraft Ventilation spray painting booths. Properly operated DOWNDRAFT booths produce lower concentrations of paint overspray compared to the other two types of booths. DOWNDRAFT booths produce a cleaner paint job that requires less buffing (Figure 1).
Figure 1

Figure 1


Respiratory Protection

Properly used and maintained HVLP spray painting guns and downdraft booths will greatly reduce paint overspray concentrations, but they will not completely eliminate overspray from the air workers breathe. Therefore, PERSONAL RESPIRATORY PROTECTIVE EQUIPMENT is also recommended and a RESPIRATORY PROTECTION PROGRAM. The Occupational Safety and Health Administration (OSHA) Respiratory Protection Standard (29 CFR* 1910.134) (www.osha.gov/SLTC/etools/respiratory/index.html) should be followed. The provisions of the program include procedures for selection, medical evaluation, fit testing, training, use, and care of respirators.
NIOSH [1995]. Hazard evaluation and technical assistance report. Spence’s Carstar, Denver, CO. Cincinnati, OH. U.S. Department of Health and Human Services, Public Health Service, Center for Disease Control and Prevention. National Institute for Occupational Safety and Health, HETA report 95-0405-2600.
NIOSH [1995]. Hazard control. Control of paint overspray in autobody repair shops. Cincinnati, OH. U.S. Department of Health and Human Services, Public Health Service, Center for Disease Control and Prevention. National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication 96-106
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auto repair
auto repair
automotive body shops
automotive body shops
paint overspray
paint overspray