Hot Work Permit: Requirements & Procedure
Hot work — welding, cutting, grinding — is a leading cause of industrial fires. This guide covers the hot work permit system, fire prevention measures, and the fire watch requirements that prevent disasters.
Fire Risk
Hot work is one of the leading causes of industrial fires. Sparks can travel 10+ metres and smoulder for hours before igniting. A properly executed hot work permit system prevents these fires.
What is Hot Work?
Hot work includes any activity that generates heat, sparks, or open flame:
- Welding (arc, MIG, TIG, gas)
- Cutting (oxy-acetylene, plasma, grinding)
- Grinding (angle grinder, disc grinder)
- Soldering and brazing
- Using open flame (torches, heat guns)
- Drilling or chipping that could create sparks (in hazardous areas)
Pre-Work Checklist
☐ Hot work permit completed and authorised
☐ Area within 10 metres cleared of combustibles (or covered with fire blankets)
☐ Floor drains within 10 metres covered — sparks can enter drains and ignite flammable residues
☐ Wall and floor openings within 10 metres covered — sparks can travel through openings
☐ Combustible materials that cannot be removed are protected with fire-resistant blankets
☐ Fire extinguisher (appropriate type) available within 3 metres of the work
☐ Fire watch assigned — a dedicated person whose only job is to watch for fire
☐ Gas testing completed — atmosphere checked for flammable gases (below 10% LEL) before work starts
☐ Ventilation adequate — ensure fumes are extracted
☐ All other work in the area stopped — no simultaneous hot work and flammable work
☐ Adjacent areas checked — sparks can travel through walls, ducts, and openings
Fire Watch Requirements
- A fire watch must be present during ALL hot work and for at least 30 minutes after work is completed (some jurisdictions require 1 hour)
- The fire watch must have NO other duties — their only job is to watch for fire
- The fire watch must be trained in using fire extinguishers
- The fire watch must have a means of communication (radio, phone) to call for help
- If the work is in a high-risk area (process plant with flammable materials), consider continuous monitoring for several hours after work
- If the hot work is in a concealed space (above a ceiling, inside a wall), the fire watch must continue for at least 2 hours after work is completed
Alternative: Cold Work
Before issuing a hot work permit, consider whether cold work methods could be used instead:
- Mechanical cutting (saw, pipe cutter) instead of oxy cutting
- Mechanical bolting instead of welding
- Epoxy bonding instead of welding
- Cold repair composites for pipe repair
- If cold work is feasible, it should always be preferred over hot work