Confirm where spraying happens and what is sprayed, then trace the booth or room, its exhaust and makeup air, interlocks, fire protection, classified electrical areas, and material storage through every discipline. AI can flag conflicts; the designer and the authority having jurisdiction decide compliance.
What does NFPA 33 cover?
NFPA 33 is the Standard for Spray Application Using Flammable or Combustible Materials. NFPA describes it as providing requirements to mitigate fire and explosion hazards of spray application processes that use flammable or combustible materials.
NFPA’s official NFPA 33 page identifies the 2024 edition as current when checked on October 4, 2026. Confirm the edition, local amendments, and project scope that actually govern the work. The publisher’s newest edition does not establish local adoption.
Dipping, coating, and printing processes are a separate NFPA standard, and storage of the liquids themselves may fall under the NFPA 30 guide. The booth exhaust ductwork connects to the NFPA 91 process exhaust guide. Where the jurisdiction uses the International Fire Code, record how it points to NFPA 33 before citing either.
Collect the booth and every system it touches
Bring the floor plan showing the booth, spray room, or spray area, the booth vendor drawings, the mechanical exhaust and makeup air drawings, the fire protection drawings for the booth and its ductwork, the electrical plans with classified-area boundaries, the fire alarm or interlock diagrams, and the storage plan for coatings and solvents.
Note whether the project uses a prefabricated booth, a built spray room, or an open spray area. Each one puts the answer on different sheets.
Trace the spray process through the set
| Review question | Sources to compare | Decision to record |
|---|---|---|
| Spray area | Floor plans, booth vendor drawings, code summary | Confirm the booth or room is drawn in the same place and size on every sheet. |
| Exhaust and makeup air | Mechanical plans, fan schedule, booth data | Match the booth exhaust fan, duct, and makeup air unit across the mechanical and vendor sheets. |
| Interlocks | Sequences, electrical diagrams, booth data | Check that the spray equipment, exhaust, and makeup air interlocks agree between documents. |
| Fire protection | Fire protection plans, booth data, specifications | Confirm the booth, plenum, and duct protection shown on the fire protection drawings matches the vendor package. |
| Classified areas | Electrical plans, hazardous-area drawings, equipment schedules | Identify electrical equipment inside the drawn classified area that is not specified for it. |
| Material storage | Floor plans, storage room plans, specifications | Check where coatings and solvents are stored and mixed and whether every sheet agrees. |
Carry classified areas into the NFPA 70 electrical guide, sprinkler protection into the NFPA 13 sprinkler guide, and the full package into the mechanical drawing checklist.
Example: a booth that moved after the electrical layout
Hypothetical example. A revised floor plan shifts the spray booth toward an exterior wall, but the electrical plan still shows the classified-area boundary around the old location, with a panel now inside the new boundary.
The floor plan and booth vendor drawings place the spray booth in a different location from the classified-area boundary on the electrical plan. Please confirm the booth location and revise the classified area and equipment layout to match.
The electrical engineer updates the boundary and relocates or respecifies the panel. Whether the classification meets the adopted code is the engineer’s and authority’s decision.
Review spray booth documents with Groundbook
Upload the current project PDFs and relevant specifications to Groundbook. Identify the governing issues and add the applicable NFPA 33 reference from a copy you are licensed to use, where the license permits uploading it. State the edition, amendments, review area, and known exclusions in your instructions.
Compare the floor plans, booth vendor drawings, mechanical exhaust and makeup air drawings, fire protection drawings, electrical classified-area plans, interlock diagrams, and storage plans. Flag booth locations, exhaust, interlocks, protection, classified areas, and storage that differ between sources. Use the supplied NFPA 33 edition where applicable and cite both sources.
Groundbook links each potential finding to the sheets behind it. Keep missing vendor data separate from drawings that disagree with each other.
Document review does not classify hazardous locations, size exhaust or makeup air, or approve the booth. Those decisions remain with the design professionals, the booth manufacturer, and the authority having jurisdiction.