Customer cars covered while they're yours.

The federal paint booth rule: 6H in every state

EPA's area-source rule for surface coating, 40 CFR part 63 subpart HHHHHH, covers autobody refinishing, meaning spray-applied coating of motor vehicles and mobile equipment. It even reaches an individual who spray-coats more than two vehicles a year, paid or not. Section 63.11173 sets the shop-floor rules:

• Filters. Every spray booth, prep station and mobile enclosure needs filters shown to capture at least 98 percent of overspray. Water-wash booths run and maintained to the manufacturer's specifications are excepted.
• Enclosure. Booths and prep stations used to refinish complete vehicles need a full roof, four complete walls or side curtains, and negative pressure that draws air in through any openings; a fully sealed booth with automatic pressure balancing may run up to 0.05 inches water gauge positive.
• Guns. HVLP, electrostatic, airless or air-assisted airless, or an equivalent EPA approves in writing.
• Gun cleaning. No atomized mist of solvent and paint outside a collecting container: hand cleaning, flushing without atomizing, or a fully enclosed gun washer.
• Painters. Training and certification within 180 days of hire, refresher training and recertification every five years, and a current list of everyone required to be trained. People who aren't certified may not spray.

State and local air agencies add their own permits and rules. When I put a body shop in front of carriers, the painter certification list goes in the file with the booth details.

Painters' lungs: Cal/OSHA booth and respirator rules

In California, Title 8 section 5153 sets the booth rules for spray coating. Mechanical ventilation runs while spraying and long enough afterward to exhaust flammable vapors from drying work, and it must keep those vapors under 20 percent of their lower explosive limit. Exhaust air can't be recirculated, make-up air should be supplied, no make-up air heater may sit in the booth, and downdraft booth doors stay closed while painting. A booth operator positioned downstream of the object being sprayed must wear a respirator, and that use must meet section 5144, which requires:

• A written respiratory protection program with worksite-specific procedures, run by a qualified program administrator.
• Respirators, training and medical evaluations at no cost to the employee.
• A medical evaluation before the employee is fit tested or required to use the respirator.
• For tight-fitting facepieces, a fit test before first use, whenever a different facepiece is used, and at least annually.
• Training before required use, and retraining annually.

Outside California, the rules vary by state. With a body shop's workers' compensation insurance submission I include the written program, because painters are the employees the underwriter reads about first.

Official sources

• South Coast AQMD Rule 1151 (amended November 1, 2024)
• South Coast AQMD Rules 201, 203 and 206 (permit to construct, permit to operate, posting)
• 40 CFR 63.11173, surface coating requirements (Cornell LII)
• 40 CFR 63.11169, scope of subpart HHHHHH (Cornell LII)
• 22 CCR 66262.18, EPA identification numbers and re-notification (Cornell LII)
• 22 CCR 66262.16, small quantity generator conditions (Cornell LII)
• Cal/OSHA Title 8 section 5153, spray coating ventilation and PPE
• Cal/OSHA Title 8 section 5144, respiratory protection
• California Business and Professions Code 9884.9 (california.public.law)
• IRMI: The CGL Pollution Exclusion (Craig Stanovich, May 7, 2021)