Hot Work Safety Guidelines


Hot Work activities present unique hazards to workers that could result in injury, and that could also result in the potential loss of property if not controlled. This document sets forth the minimum safe work practice requirements when Hot Work activities are performed at the University’s facilities. It is intended to provide University departments that perform or contract for these types of activities with general guidance on developing or improving their own safe work procedures based on the types of hazards, and conditions present, and also to prevent disruptions to University community activities due to unnecessary activation of building fire detection and alarm systems.


Consistent with the University Environmental Health and Safety (EHS) Policy, each University department that performs or contracts for activities deemed as hot work are responsible for its safe completion and shall ensure for the implementation of these guidelines.  It is the responsibility of every Supervisor to adhere to the safe work practices listed in this document and to ensure a safe working environment that complies with the Ontario Occupational Health and Safety Act (OHSA) and applicable regulations, standards, and guidelines.


These guidelines are applicable to any University departments that performs or contracts for activities deemed as hot work.


Prior to carrying out any hot work, it should first be determined if there is any alternative method which could be used instead. Alternatives include:

  • Bolting versus welding
  • Hydraulic shears or reciprocal saw versus torch or radial saw cutting
  • Mechanical clamps versus welding
  • Threaded final pipe or tube connections versus torch soldered joints
  • Roof covering system which is not torch-applied
  • Hand filing versus mechanical grinding

Hot Work Safety Practices

5.1 General Safety Precautions

  • Communication device(s) is available for immediate use in case of an emergency.
  • Hot work permit is posted in a conspicuous location.
  • Fire extinguishing device(s) are present, in service, and in good operating condition.
  • Smoke/Heat detectors and sprinkler systems affected have been noted and temporarily disabled. While disabled the building’s fire safety plan’s alternative measures shall be implemented, and notification communicated to the building occupants.
  • Hot work equipment is inspected, and is in good operating condition
  • An assessment has been completed, and steps implemented to mitigate risks to workers when completing the work.
  • Appropriate Personal Protective Equipment is provided and in good condition.

5.2 Requirements Within 15 Metres of Hot Work

  • Work area is clearly delineated with signs and/or barriers to restrict access.
  • Smoke/Heat detectors and sprinkler systems are covered if vulnerable due to the work.
  • Area is ventilated with appropriate equipment if there is a risk due to atmospheric hazards.
  • Nearby activity that could contribute to atmospheric hazards shall be suspended.
  • Risk of explosive atmosphere is eliminated (gases, vapours, dust)
  • All flammable liquids, dust, powders and oily products have been removed from the area.
  • All combustible materials have been removed from the work area, or are protected with fire-resistive tarpaulins/blankets.
  • Floors are swept.
  • Openings in floors, walls, and ceiling are covered with non-combustible materials. (Includes return air plenums)

5.3 Work on or within Partially Enclosed Equipment

  • Confined Space Permit Required.
  • Hot Work shall not be performed on a totally enclosed container.
  • Partially enclosed equipment shall be cleaned of all combustibles, and be purged of any materials which could create an explosion hazard. Testing is required to confirm the absence of an explosion hazard.
  • Piping an equipment shall be removed from service, isolated, and vented.

5.4 Hot Work Monitoring (During and after work completion)

  • A Fire Watch shall be established to monitor the work and adjoining areas during the course of the work, and for a minimum of 3 hours upon its completion.
  • The Fire watch shall be trained in the use of the fire extinguishing device(s) available, and know the location of the nearest fire alarm pull station.

Figure 1: Sample Hot Work Permit