Spray Booths & Finishing Rooms
Spraying paint, lacquer and coatings fills the air with flammable vapor and fine mist. A spray booth is designed to pull that vapor away from you and away from ignition sources. It only works if the fans run, the filters are clean and nothing that can spark gets inside.
- General Industry
- Auto Body
- Manufacturing
The rules
OSHA’s spray finishing rule (29 CFR 1910.107) and NFPA 33 cover booth construction, ventilation, electrical equipment and fire protection. Local fire codes usually require permits for spray booths.
Ventilation
- The exhaust fan must run whenever spraying happens. Many booths have an interlock so the spray gun won’t work unless the fan is on. Never bypass it.
- Change intake and exhaust filters on schedule. Clogged filters cut airflow and let vapor build up.
- Watch the airflow gauge (manometer), and report readings outside the marked range.
- Keep the fan running for a while after spraying stops to clear the vapor.
Keep ignition sources out
- Electrical equipment in and near the booth must be rated for hazardous (classified) locations.
- No open flames, grinding, welding, smoking or spark-producing tools in or near the spray area.
- Ground the parts being sprayed, the spray equipment and metal containers to prevent static sparks. See Static, Bonding & Grounding.
- Use non-sparking scrapers to clean residue.
Residue, filters and waste
- Overspray residue is flammable. Clean booth walls and floors regularly.
- Used filters and rags soaked with some finishes can heat up and catch fire on their own. Put them in a covered metal container or as your waste plan requires, and remove them from the building daily. See Oily Rags.
- Keep only the paint and solvent you need for the shift in the spray area. Store the rest in approved cabinets or a mixing room. See Flammable Liquids.
Fire protection
Booths usually have automatic sprinklers or a fire suppression system. Keep sprinkler heads clean; many shops cover them with thin bags made for this purpose, changed often. Keep extinguishers nearby and exits clear.
Protecting your lungs and skin
- Many two-part urethane paints contain isocyanates, a leading cause of work-related asthma. A supplied-air respirator is often recommended when spraying them. See Isocyanates.
- Solvents can cause dizziness and long-term nerve damage. See Solvents.
- Wear chemical-resistant gloves, coveralls and eye protection as the safety data sheet requires.
- Respirators need fit testing and a medical evaluation. See Respiratory Protection.
Before you spray
- Exhaust fan running and airflow gauge in range
- Filters in good condition
- Parts and equipment grounded
- No ignition sources in or near the booth
- Respirator checked and the right cartridges or air supply ready
- Only the day’s paint in the spray area
Standards & references
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