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Hot work: don’t play with fire

Hot work is one of the most frequent causes of fire in the workplace. What precautions should be taken when welding or soldering, or when using tools that create sparks? We have some expert advice.

What is hot work?

When we talk about hot work, we’re talking about work done with tools that use a naked flame or produce heat or sparks. For example, welding and related processes such as arc welding, oxy-fuel gas welding, open-flame soldering, soldering, thermal spraying, oxygen cutting, and arc cutting.
Note that hot work is regulated by section 5.2 of the National Fire Code.

Before you start

Use the right method

In food, wood and plastic processing plants, recycling centres, and commercial and industrial buildings, hot work is used for a variety of tasks (repairing infrastructure, cutting metal, etc.). But they might not always be the most appropriate, or the safest. Hot work could often be replaced with other processes. Here are some examples:

Soldering Mechanical bolting
Saw or torch cutting Manual hydraulic sharing
Radial saw or torch cutting Mechanical pipe cutting

Prepare the work area

Ideally, the hot work should be performed in a designated fire-safe area such as a maintenance shop. As you’re working with tools that produce sparks, it’s important to clear the area of any combustible or flammable material. Here are a few precautions to take:

Checklist – Work area

  • If possible, choose a maintenance workshop or isolated outdoor area.
  • Ensure that the chosen workshop is made of fireproof or fire-resistant material. Inspect the area to ensure that structural elements (dividers, walls, ceilings) don’t contain combustible material.
  • Remove any flammable, combustible or explosive material within 11 m (35 ft.) of the work area.
  • If this material can’t be moved elsewhere, cover it with a thermal protective shield or fire-resistant tarpaulins. Pay special attention to gas pipes and equipment that sparks or hot material could come into contact with it.
  • Clean the floor to remove any trace of combustible material (such as sawdust, dust, grease or oil). If the floor is made of combustible material, dampen it with water or cover it with fire-retardant tarps or wet sand.
  • Vacuum away combustible debris from inside ventilation or other service duct openings to prevent ignition. Close ventilation ducts and seal cracks to keep smoke from spreading throughout the building. Cover duct openings with fire-resistant material.
  • Verify that the equipment used for hot work is in good working order.
  • Check that the automated fire protection system is activated and fully operational.
  • Keep a hose and fire extinguishers within reach.
  • To avoid electrocution, only use water AFTER electrical circuits have been turned off.


During hot work, someone (fire watch) should keep an eye on the sparks or flames produced. All sources of ignition must remain in the secure area and the hot work permit must be clearly visible.


As sparks produced when carrying out hot work can remain dormant before catching fire, keep a close eye on the area for a full hour after the work is done. Inspect the area once every hour for three hours, and keep a record of the process.

To ensure the safety of you and your workers, see that you’ve fully understood, evaluated and managed the risks associated with hot work. Refer to your broker or loss prevention representative for additional details.

This document is provided for information purposes only and should not be considered exhaustive or as advice. Intact Insurance makes no representation and offers no guarantees that using this information will prevent damage or reduce your premium. Your insurance contract prevails at all times; consult it for a full description of guarantees and exclusions. Certain conditions, limitations and exclusions apply.

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