Hot Work
What is Hot Work? Hot work is any operation involving open flames or producing heat and/or sparks capable of initiating fires or explosions. This includes welding, brazing, cutting, soldering, grinding, torching, and similar spark- or heat-producing tasks. Hot work requires strict site controls and may require a designated permit and fire watch.
Need a Hot Work Permit? Request permits through your scheduler or submit the online request form via FP&M Fire & Life Safety Hot Work Permit Form.
Hot Work Activities & Ignitable Materials
Common Hot Work Activities
- Welding (including pin and orbital welding)
- Brazing & Soldering
- Carbon-arc gouging
- Torching & Torch-applied roofing
- Smelting & Heat treating
- Hot riveting
- Grinding, Chipping, & Abrasive blasting
- Cutting (including chop saws and plasma cutters)
Note: Unlisted activities producing sparks, heat, or flame must also be assessed for ignition potential before work begins.
Examples of Common Ignitable Materials
- Wood, Paper, and Cardboard
- Insulation & Building Finishes
- Flammable Chemicals & Solvents
- Combustible Dusts & Hazardous Gases
Permit Requirements & Location Restrictions
What is a Hot Work Permit?
A Hot Work Permit is an authorized document posted at the job site containing critical safety details, including: date and time of work, specific location, scope of hot work, assigned safety team members, and mandatory fire prevention controls implemented prior to starting work.
When is a Permit Required?
A Hot Work Permit is required anytime hot work operations are conducted outside of a pre-approved Designated Hot Work Area.
Where is Hot Work Strictly Prohibited?
Hot work is unacceptable and cannot proceed in locations with any of the following conditions:
- Areas not authorized by Management, the PAI, or EHS Fire & Life Safety.
- Areas with explosive atmospheres or combustible dust levels capable of posing a flash fire hazard.
- Areas with uncleaned equipment, tanks, drums, or containers that may produce explosive or toxic vapors when heated.
- Areas where fire protection systems (sprinklers, smoke detectors) are impaired without approved alternative safety precautions.
Prohibited Practice: Taping over, placing plastic bags, or putting unapproved coverings over smoke detectors is never an acceptable form of impairment mitigation at UW-Madison.
Designated Hot Work Areas
A Designated Area is a permanent, dedicated space optimized for hot work (such as a shop). Before work starts in a designated area, it must be verified that it meets all of the following criteria:
- Constructed of fire-resistant materials.
- Posted with required warning signage as specified by the PAI.
- Inspected at least annually by the PAI (EHS Fire & Life Safety).
- Equipped with fully inspected, accessible fire extinguishers nearby.
- Maintained with properly functioning machinery and tools.
- Provided with adequate and operational local exhaust ventilation.
If any of these conditions are missing or compromised, the area loses its designated status and work requires a Hot Work Permit until corrected.
Hot Work Safety Team Roles (NFPA 51B)
Per NFPA 51B, a hot work safety team requires three distinct roles. All roles are empowered and required to stop work immediately if conditions become unsafe or deviate from the approved permit.
Inspects the work site, identifies hazards, verifies combustible separation, determines required PPE, issues hot work permits, and enforces work shutdowns or extended fire watches when hazards arise.
The technician performing the hot activity. Must obtain PAI approval before starting, inspect tools/site conditions, adhere strictly to permit scope, and stop work if conditions become hazardous.
Trained individual who monitors the hot work site for ignition risks and sparks. Equipped and trained to sound the fire alarm and use a fire extinguisher. Authorized to stop unsafe work.
Note: Both the Operator and Fire Watch are required to read, understand, follow, and sign the Hot Work Permit.
Fire Watch Requirements & Duration
When is a Fire Watch Required?
- Mandated by the PAI or EHS Fire & Life Safety regardless of location or work scope.
- Hot work is performed outside a designated area and within 35 feet of easily ignitable materials or wall/floor openings.
- Combustible materials are adjacent to the reverse side of metal partitions, walls, or ceilings being worked on.
- The operator wears PPE that has a potential to ignite, hold sparks, or create shock hazards.
- Conditions allow for anything greater than a minor, well-contained fire to develop.
Duration & Duties
- Standard Duration: Fire watch must remain posted for at least 1 hour after all hot work operations have completely stopped.
- Extensions: The PAI or EHS Fire & Life Safety may extend the fire watch duration beyond 1 hour if site hazards warrant added monitoring.
- Secondary Tasks: The fire watch may perform light secondary duties (such as area housekeeping) only if these duties do not distract them from continuously observing the site and responding immediately to fire risks.
Regulatory Standards & Contact Information
Applicable Regulatory Standards
UW-Madison hot work operations strictly adhere to:
- NFPA 51B (2019 Edition): Standard for Fire Prevention During Welding, Cutting, and Other Hot Work
- OSHA 29 CFR 1910 Subpart Q: Welding, Cutting, and Brazing (General Industry)
- OSHA 29 CFR 1926 Subpart J: Welding and Cutting (Construction Industry)
Contact & Assistance
For questions regarding hot work permits, site evaluations, or policy compliance, contact your supervisor or EHS Fire & Life Safety:
- Email: firelife@fpm.wisc.edu
- EHS Front Office Phone: (608) 265-5000