The Importance of Paint Booth Regulations

Because spray paint materials are often caustic, flammable and potentially toxic to both employees and the environment, spray booths are utilized to protect operators through effective ventilation and contained exposure. Paint booth regulations exist to help ensure the proper construction, operation and maintenance of spray booths to further limit liability.

Naturally, there are a lot of regulations to consider when evaluating the efficacy of a spray booth. So many, that it can often feel overwhelming and even at times unfair for operators that lack the means to contract proper guidance. Below is an easy-to-use paint booth regulations checklist designed to help overcome some of these initial frustrations and further ensure proper compliance.

How to Use Our Compliance Checklist

This paint booth regulations checklist is designed to accommodate federal regulations issued by the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) as well as National Fire Protection Association (NFPA) standards.

Behind each listed item is a bracketed citation that directs readers to the relevant code. [29 CFR…] refers to OSHA’s general industry standards, while [NFPA…] applies to the applicable NFPA standards. While going through this checklist, it is not necessary to check every standard, though if you notice a violation we recommend reading more about it. We have also included some definitions at the end of the checklist, to help with any confusion.

Keep in mind that any violation of a listed item is a potentially serious liability and should be addressed immediately and proper compliance means satisfying every requirement listed. Additionally, this checklist serves as a well-researched point of reference but is not intended to function as official regulatory guidelines.

Note: Bolded items may require expert opinion and consultation. While we always suggest seeking the advice of a trusted professional, bolded items indicate that we strongly recommend readers to urge on the side of caution and contract reliable experts.

General Paint Booth Regulations

  1. Smoking and open flames should be prohibited in any spray-finishing area. [NFPA 1 and 33]
  2. Spraying and finishing areas should be posted with clearly visible signage reading “No Smoking”  [29 CFR 1910.107(g)(7)]
  3. A sufficient supply of portable fire extinguishers should be closely located near all spraying areas. Expert opinion may be required. [29 CFR 1910.107(f)(4)]
  4. Metal waste cans with self-closing lids should be provided wherever rags or waste are soaked with finishing material. Additionally, all soaked rags or waste should be deposited in metal waste cans immediately after being used. [NFPA 1 and 33]

Spray Booth Construction

  1. Spray booths should be constructed with securely and rigidly supported steel, concrete or similar masonry. [29 CFR 1910.107(b)(1)]
  2. All spray booth floor and baffle plates (grates) should be constructed with noncombustible material. [29 CFR 1910.94(c)(3)(iii)]
  3. Spray booth interiors should be designed to be continuously smooth and without edges to prevent accumulation of residues. [29 CFR 1910.107(b)(2)]
  4. To reduce hazard, spraying operations and booths should be separated from other operations by at least three feet in space, or by a suitable partition or wall [29 CFR 1910.107(b)(8)]
  5. Spray booths should be installed so that all portions are readily accessible for cleaning. [NFPA 1 and 33]
  6. Spraying areas should be illuminated through glass panels or other translucent materials, and only fixed lighting units should be used as a source of illumination.  [29 CFR 1910.107(b)(10)]
  7. All motors, wiring and lighting fixtures that are not separated by a partition and located within 20 feet from spray finishing operations should be explosion proof. Expert opinion may be required. [29 CFR 1910.94(c)(3) and 1910.107(c)(6)]
  8. Spray booth interiors should be protected with an automatic fire sprinkler system. [29 CFR 1910.107(b)(5)(iv)]
  9. All hot surfaces (such as steam pipes, appliances and space heaters) should be located away from spray-finishing operations. [29 CFR 1910.107(c)(3)]
  10. All metal parts of spray booths, exhaust ducts and piping systems should be permanently and effectively grounded. Expert opinion may be required. [29 CFR 1910.107(c)(9)(i)]

Operations and Maintenance Regulations

  1. Spray booth interiors should be free from accumulated deposits prior to operation. Note: combustible coverings (plastic, thin paper, etc.) and strippable coatings can be used to facilitate cleaning operations. [29 CFR 1910.107(b)(2) and (g)(2)]
  2. All tools used for scraping residues and debris should be non-sparking. [29 CFR 1910.107(g)(2)]
  3. All residue scrapings and debris should be immediately removed from the premises and disposed of properly. [29 CFR 1910.107(g)(3)]
  4. All cleaning solvents should be restricted to those with flash points above 100ºF. [29 CFR 1910.107(g)(3)]
  5. Cleaning operations using flammable or combustible solvents inside spray booths should be conducted with ventilation equipment operating during the cleaning process. [NFPA 33]
  6. Fire sprinkler heads should be kept free of accumulated deposits. [29 CFR 1910.107(f)(3)]
  7. All spray booth overspray filters should be routinely inspected, cleaned and replaced. [29 CFR 1910.94(c)(3)(iii)(a)]
  8. All spray booth overspray filters discarded at the end of each day unless maintained completely in water. [29 CFR 1910.107(b)(5)(ii)]
  9. At least 3 feet on all sides of a spray booth should be maintained to be free of any stored combustible materials. [NFPA 33]

Paint Booth Regulation for Flammable and Combustible Liquids

  1. Only one day’s worth of flammable or combustible liquids should be kept near spraying operations. [29 CFR 1910.107(e)(2)]
  2. All flammable and combustible liquids must be transported in either closed containers, approved portable tanks, approved safety cans or closed piping. [29 CFR 1910.107(e)(3)]
  3. All flammable and combustible liquids in containers larger than 60 gallons should be transported by means of an approved pump. [29 CFR 1910.107(e)(4)]
  4. All containers or pipes attached to flexible hoses must have shut off valves at their connections. [29 CFR 1910.107(e)(6)(i)]
  5. When flammable liquids are transferred from one container to another, both containers should be grounded and bonded. [29 CFR 1910.107(e)(6)(iv)]
  6. All containers supplying spray nozzles should be a closed type or provided with a metal cover. [NFPA 33]
  7. Containers supplying spray nozzles resting on floors, or noncombustible supports should be suspended by wire cables. [NFPA 33]
  8. Containers supplying spray nozzles by gravity flow should be less than 10 gallons. [NFPA 33]
  9. If flammable or combustible liquids are supplied to spray nozzles by positive displacement pumps, the discharge pressure should be preventing from exceeding the operating pressure of the system. [NFPA 33]

Ventilation Requirements

  1. Spraying areas must be provided with mechanical ventilation that is kept in use during operation.  [29 CFR 1910.107(d)(2)]
  2. Spraying operations should have sufficient ventilation to maintain individual exposure within acceptable limits. Expert opinion may be required. [29 CFR 1910.94(c)(4)(iii)]
  3. Spray booths should be designed to sweep air currents towards exhaust outlets. [29 CFR 1910.107(b)(a)]
  4. All exhaust ventilation systems should be well constructed and in good working order prior to operation. [29 CFR 1910.94(a)(5),(6),(7)]
  5. The average velocity of airflow intake through the face of the spray booth should be at least 100 feet per minute. Note: electrostatic spraying operations can be conducted with an average airflow velocity of at least 60 feet per minute. Expert opinion may be required. [29 CFR 1910.94(c)(6)(i) and 1910.107(b)(5)(i)]
  6. Visible gauges, audible alarms or pressure-activated devices should be installed to indicate or insure that the required air velocity is maintained. [29 CFR 1910.107(b)(5)(i)]
  7. Doors to downdraft booths should always be kept closed when the booth is in operation. [29 CFR 1910.94(c)(6)(iii)(b)]
  8. Clean, fresh makeup air should be supplied to the area to replace the volume of air exhausted through the spray booth. Note: if outdoor temperature is less than 55ºF, makeup air must be heated. [29 CFR 1910.94(c)(7)(i)]
  9. All spray booths must have independent exhaust stacks that direct outside the spray booth environment. [29 CFR 1910.107(d)(3)]
  10. All fan-rotating elements should be constructed of non-ferrous or non-sparking materials. [29 CFR 1910.107(d)(4)]
  11. Electric motors driving the exhaust fans should be placed outside of booths and ducts. [29 CFR 1910.107(d)(5)]
  12. Belts and pulleys in ducts used to drive the fan blades should be thoroughly enclosed.[29 CFR 1910.107(d)(6)]
  13. Spray booth exhaust duct terminals must be located at least six feet from any combustible exterior wall or roof and prevented from discharging in the direction of any combustible construction. [29 CFR 1910.107(d)(8)]
  14. Spray booth exhaust air should be directed so that it will not contaminate makeup air or create a measurable nuisance to the spray environment. [29 CFR 1910.107(d)(9)]
  15. All exhaust ducts should be fitted with access doors for cleaning. [29 CFR 1910.107(d)(10)]
  16. Freshly spray-finished items and articles should be set to dry in areas with adequate ventilation. If not, these areas should be treated as spraying areas and subject to all similar regulatory requirements. [29 CFR 1910.107(d)(12)]

Electrostatic Apparatus Codes

  1. Only approved electrostatic equipment should be used in connection with paint-spraying operations. [NFPA 33]
  2. Transformers, power packs, control apparatus and all other electrical portions of the equipment should be located outside of the spraying or vapor areas (with the exception of high-voltage grids and electrostatic atomizing heads). [NFPA 33]
  3. A space of at least twice the sparking distance must be maintained between painted items and fixed electrodes, electrostatic atomizing heads or conductors. Note: a suitable sign stating the sparking distance should be posted near the assembly. [NFPA 33]
  4. Electrostatic apparatuses should be equipped with automatic controls that operate without time delay to disconnect the power supply to the high-voltage transformer as well as signal to the operator any of the following conditions. [NFPA 33]
    1. Ventilating equipment fails or ventilation fans stop.
    2. Conveyors carrying items past high-voltage grid stops.
    3. The primary voltage input to the power supply de-energizes
    4. A ground or imminent ground occurs at any point of the high voltage system.
  5. Adequate booths, fencing, railings or guards should be placed around the equipment to safely isolate their process from storage and persons. Note: such railings, fencing and guards should be adequately grounded, constructed of conducting material and spaced at least five feet from the processing equipment. [NFPA 33]
  6. Signs should be posted designating the process zone as hazardous (e.g. with respect to fire) [NFPA 33]
  7. All insulators should be kept clean and dry. [NFPA 33]

Paint Booth Regulations Definitions

Approved: verified and listed by a nationally recognized testing laboratory.

Bonded: the permanent joining of metallic parts to form an electrically conductive path that will assure electrical continuity and the capacity to conduct safely any current likely to be imposed.

Combustible: any liquid having a flashpoint at or above 100ºF but below 200ºF.

Flammable: any liquid having a flashpoint below 100ºF.

Grounded: connected to the earth or to some conducting body that serves in place of the earth.

Spraying Area / Spraying Environment: any area in which dangerous quantities of flammable vapors or mists or combustible residues, dusts, or deposits are present because of spraying processes. This includes the interior of spray booths, the interior of ducts exhausting from spraying processes, and any area in the direct path of spray.

Spray Booth / Paint Booth: a power-ventilated structure that encloses or accommodates a spraying operation to confine and limit the escape of spray, vapor, and residue and to conduct or direct them safely to an exhaust system.

Compliance and Custom Booth Solutions

At Spray Systems, we understand that the design and implementation of your spray booth can be an extremely challenging and confusing process. However, with our guidance, it doesn’t have to be.

Our goal is to provide you with all the needed information and resources to ensure that there are no unnecessary surprises or questions throughout the process. Although the operational efficiency of your spray booth is important, we firmly believe that there is nothing more important than ensuring the safety of employees and minimizing the impact of the environment. That’s why it’s important to view federal and local safety codes as necessary guidelines put in place to ensure employee safety and reduce unnecessary liability.

Have Questions? Contact Us.

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NFPA 33 FAQS

General Compliance

What is NFPA 33, and who needs to comply with it?

NFPA 33 is the national standard for spray application using flammable or combustible materials. Any facility that operates spray booths, spray rooms, or spray areas for industrial coating applications must comply with NFPA 33. This includes aerospace manufacturers, automotive facilities, furniture manufacturers, and any industrial operation using spray-applied coatings.

Is NFPA 33 legally required?

While NFPA 33 itself is a standard, not a law, it is typically adopted and enforced by local authorities having jurisdiction (AHJ), OSHA regulations, insurance companies, and building codes. Non-compliance can result in fines, shutdown orders, insurance issues, and increased liability in case of accidents.

How often is NFPA 33 updated?

NFPA 33 is typically revised every 3-5 years. The current edition is 2018, with updates expected periodically. It’s important to verify which edition your local jurisdiction has adopted, as they may not immediately adopt the newest version.

Booth Design & Construction

What’s the minimum distance required between a spray booth and other operations?

Spray booths must be separated by either 3 feet of clear space OR a partition with a 1-hour fire resistance rating. Multiple connected spray booths are considered a single operation and don’t require separation from each other.

Ventilation & Air Flow

Can I recirculate air from my spray booth back into the plant?

For liquid spray operations, recirculation is only allowed if you meet ALL requirements, including: particulate filters, vapor monitoring below 25% of the lower flammable limit, automatic shutdown systems, and AHJ approval. Powder coating booths have more flexibility for recirculation with proper filtration and monitoring.

Do exhaust fans need to run continuously?

Yes, ventilation must operate during all spray operations AND continue afterward long enough to exhaust vapors from drying coatings. Automatic spray equipment must be interlocked so spraying cannot occur without ventilation running.

What type of fans are required?

Fans must be spark-resistant and constructed of materials appropriate for the materials being sprayed. The fan motor must be located outside the airstream or be rated for the hazardous location classification.

Electrical & Safety Systems

What electrical equipment can I use inside the spray booth?

All electrical equipment inside the booth must be rated for Class I, Division 1 hazardous locations. This includes lights, switches, outlets, and any control equipment. Equipment within 3 feet of booth openings must be Class I, Division 2 rated.

Do I need explosion-proof lighting?

Not necessarily. Lights separated from the spray area by approved glass panels and serviced from outside can be standard-rated. However, any lights inside the classified area must meet hazardous location requirements.

Is fire suppression required?

Fire suppression requirements depend on your local codes and the specific materials being sprayed. Automatic sprinkler systems are often required, and portable fire extinguishers must always be readily available.

Materials & Storage

How much paint can I store near my spray booth?

If your mixing room is within 6 feet of the spray area, the combined total cannot exceed 120 gallons. If separated by more than 6 feet, you can store up to 300 gallons in the mixing room and 60 gallons in the spray area.

What are nitrocellulose applications, and why do they require special handling?

Nitrocellulose lacquers are fast-drying coatings used on furniture, musical instruments, and some automotive finishes. They require special handling because overspray can spontaneously ignite. NFPA 33 requires either water-wash booths or daily cleaning of dry filters and baffles for these materials.

Can I spray different types of coatings in the same booth?

Generally, yes, but you cannot use the same filters for materials that may spontaneously ignite when mixed (like nitrocellulose and oil-based materials). Some material combinations may require complete cleaning between applications.

Powder Coating Booths

Are powder coating booths subject to different requirements?

Yes, Chapter 15 of NFPA 33 specifically addresses powder coating with unique requirements for electrical grounding, dust collection, explosion protection, and the advantage of being able to recirculate filtered air back into the plant.

Do I need explosion venting for powder coating?

Depending on the size and design of your powder system, explosion protection per NFPA 68 may be required. This typically involves explosion venting or suppression systems for dust collectors and recovery systems.

Maintenance & Operations

How often do I need to change booth filters?

NFPA 33 doesn’t specify exact intervals for standard operations, but filters must be changed when they become loaded enough to affect booth performance. For nitrocellulose applications, daily filter changes are required. Always follow manufacturer recommendations and maintain proper airflow.

Who is the “Authority Having Jurisdiction” (AHJ)?

The AHJ is typically your local fire marshal, building inspector, or OSHA representative who has the legal authority to enforce codes and approve installations. Requirements can vary by location, so it’s important to identify and work with your specific AHJ.

Where can I get a complete copy of NFPA 33?

The complete NFPA 33 standard can be purchased from NFPA.org. Free access to view (but not print or download) the standard is also available on their website with registration.