There are many opportunities to prevent pollution in the operation of auto body shops. This section describes key processes and the materials used and wastes produced in auto body facilities. Primary pollutants of concern are:
- Dust emitted during sanding operations
- Wash water contaminants from vehicle cleaning
- Volatile organic compounds (VOCs) and hazardous air emissions (HAPs) emitted during painting operations
- Hazardous wastes generated from solvents, thinners, and metal-based paints
Body Preparation
Before painting, the vehicle must be prepped. This process might include cleaning the surface of the vehicle, removing old paint by sanding or the use of chemicals; the application of fillers; and minor mechanical procedures. Wastes here can include:
- Contaminated wash water
- Leftover filler materials
- Dust (may contain heavy metals)
- Masking materials
- Spilled paint (may contain heavy metals)
- Spilled thinners/solvents (may be ignitable and/or toxic)
- Leftover paint/solvents/thinners
- Spilled or leaking automotive fluids (used oil, antifreeze, refrigerant, etc.)
- Shop towels and wipers
Clean Work Areas
By keeping work areas clean and free of filler and sanding dusts, an auto body shop can reduce the amount of time spent cleaning up and redoing paint jobs. This can be accomplished by:
- Mixing and using body filler according to container directions.
- Avoiding use of compressed air blowguns instead of careful wiping.
- Installing a central vacuum system or using sanders with portable vacuums fitted with High Efficiency Particulate Arrestor (HEPA) filters to catch dust during sanding operations.
- Avoiding use of compressed air blow guns instead of careful wiping.
- Installing a central vacuum system or using sanders with portable vacuums fitted with High Efficiency Particulate Arrestor (HEPA) filters to catch dust during sanding operations.
- Using a broom or vacuum instead of water to clean up body repair and paint preparation waste.
Paint Application
Once the vehicle is ready to be painted, the next step is to select the type of coating material and application method to be used. The application of paint can generate a large amount of waste due to poor paint transfer efficiency and the type of coating materials selected. Typical waste from this step may include:
- Volatile Organic Compounds (VOCs) and Hazardous Air Pollutants (HAPs) from applied materials. Topcoat applications release approximately 55% of the VOCs emitted during the refinishing process. The high volume of VOCs released in this step can be reduced by increasing transfer efficiency. This can be accomplished through training of painters and proper use of High Volume, Low Pressure (HVLP) spray equipment.
- Over-sprayed paint. Over half of the topcoat material can be lost as overspray. Improper application techniques waste paint and money. Paint commonly used in spray booths may be hazardous because of its ignitability and because of its contents: heavy metals (lead and chromium), polyisocyanates, and liquid organic solvents. Auto body workers may develop nervous system disorders, skin and eye irritation, respiratory sensitization, asthma and reduced lung function from exposure to paint.
- Unused surplus paints from over-purchasing or past expiration dates. By purchasing only as much as needed a shop can reduce spoilage of expired materials, save storage space, and encourage wise use of materials.
Paint Equipment Clean-up
Equipment cleaning is required when a painting process is completed, when changing colors, or during regular maintenance. Typical waste from this step may include:
- Waste or surplus paint (may contain heavy metals)
- Used paint thinners (may be ignitable and/or toxic)
- Waste masking materials and tape
- Rags/towels (may be ignitable due to solvent or paint residue)
- Empty containers
- Paint booth filters (may contain heavy metals from paint pigments)
- Used safety and personal protective equipment (such as gloves and overalls)
- VOCs – Paint equipment cleaning contributes approximately 20% of the VOCs released during the refinishing process. Source: Pollution Prevention Guides for Auto Body Shops
Vehicle Repair
Some shops perform minor automotive service and repair. Most of the wastes generated can be reused and/or recycled on- or off-site. Wastes generated in this process may include glass, metal, plastics, used tires, automotive fluids (antifreeze, used oil, gasoline, diesel, and used batteries.
General Shop Management
As with any small business, routine operations contribute to a shop’s waste streams. Wastes associated with these routine processes include:
- Office supplies (printer, copier, and fax paper, colored paper, paper cups, etc.)
- General packaging waste (wrappers, boxes, etc.)
- Water (toilets, sinks, showers, etc.)
- Office equipment (electronics and electrical equipment, lighting, etc.)
- Leaking or spilled materials
Safety Summary
- If improperly managed, the wastes discussed above can pose a serious threat to the health and safety of the shop’s employees, can damage the environment, or can endanger the community.
- Hazardous materials and wastes can cause cancer, nervous system damage, explosions, and air and water pollution.
- All employees should wear appropriate protective clothing and use respiratory equipment if they are directly involved in preparing, sanding or painting vehicles
- All employees should know what materials and equipment are used in their shop and where the Material Safety Data Sheets (MSDSs) are located.
- All employees should know what can and cannot be reused or recycled, and what can and cannot go down the drain or in the trashcan.