Hazardous Operations, Flammable and Combustible Liquids, and Special Fire Risks
Hazardous operations
Some uses create fire or explosion risk beyond ordinary occupancy: spray finishing, dipping, dust-producing processes, and storage of oxidizers or reactive materials. These operations are controlled through separation, ventilation, ignition control, and limits on quantities. The higher the hazard, the more the operation must be isolated from other uses and from egress routes.
Flammable and combustible liquids
Liquids are classified by flash point and boiling point, with flammable liquids being more hazardous than combustible ones. Requirements address storage, dispensing, containers, ventilation, spill control, and separation from ignition sources. Quantities above thresholds trigger stricter rules, and storage rooms or cabinets must be rated.
Traps
- Treating flammable and combustible liquids as interchangeable; classification depends on flash point.
- Ignoring quantity thresholds and assuming small amounts are unregulated.
- Overlooking ignition source control and bonding or grounding for dispensing.
- Forgetting that ventilation and spill containment are part of compliance.
- Assuming a rated cabinet permits unlimited quantities.
Rule of thumb
Control the fuel, the ignition, and the quantity. Worked example: dispensing a flammable liquid indoors requires approved containers, bonding and grounding to prevent static ignition, ventilation, and separation from ignition sources; storing more than the permitted cabinet quantity requires a dedicated rated storage room.
Exam approach
Identify the material class, the quantity, and the operation (storage versus dispensing), then apply the separation, ventilation, and container rules.