Fire Extinguisher & Hot Work Safety

Table of Contents

1. Purpose & Scope
2. Legal Requirements
3. What Is Hot Work?
4. Hot Work Permit System
5. Fire Watch Duties
6. Welding, Cutting & Grinding Fire Prevention
7. Fire Extinguisher Types
8. Using a Fire Extinguisher — PASS Technique
9. Site Fire Prevention Plan
10. Temporary Heating Fire Risks
11. HCMI Hot Work Procedures
12. Hot Work Safety Checklist

1. Purpose & Scope

Construction site fires cause millions of dollars in damage across Ontario each year and pose immediate life-safety risks to workers. Hot work operations — welding, cutting, grinding, brazing, and soldering — are responsible for a significant proportion of these fires. On HCMI church construction projects, hot work is performed during structural steel erection, mechanical piping, roofing, and various finishing operations. Additionally, temporary heating during cold weather introduces fire hazards that must be managed carefully.

This guide covers the HCMI hot work permit system, fire watch procedures, fire extinguisher use, and site fire prevention planning. It applies to all HCMI employees and sub-trades who perform hot work, operate temporary heating equipment, or are responsible for fire prevention on HCMI-managed projects.

2. Legal Requirements

• O. Reg. 213/91 s.52 (Construction Projects): Requires that temporary heating equipment be installed, maintained, and used so as not to constitute a fire hazard. Adequate ventilation must be provided.
• O. Reg. 213/91 s.53: Fire extinguishers of suitable type and size must be provided and maintained in good working order near operations that create a fire hazard, including welding, cutting, and temporary heating.
• O. Reg. 213/91 s.54: No person shall smoke or use an open flame near flammable or combustible materials unless adequate fire prevention measures are in place.
• O. Reg. 213/91 s.55-56: Requirements for compressed gas cylinder storage and use, including separation of fuel gas and oxygen cylinders, and securing cylinders to prevent tipping.
• Ontario Fire Code (O. Reg. 213/07), Division B, Part 5: Requirements for hot work permits, fire watch, and fire safety during construction and demolition.
• OHSA s.25(2)(h): General duty to take every precaution reasonable in the circumstances for worker protection.
• NFPA 51B — Standard for Fire Prevention During Welding, Cutting, and Other Hot Work: Industry standard referenced by the Ontario Fire Code for hot work procedures.

3. What Is Hot Work?

Hot work is any operation that produces sparks, open flames, or sufficient heat to ignite combustible materials. On HCMI projects, this includes:

• Welding: Arc welding (MIG, TIG, stick), oxy-fuel welding — used for structural steel, mechanical piping, and miscellaneous metals
• Cutting: Oxy-acetylene cutting, plasma cutting — structural steel and sheet metal fabrication on-site
• Grinding: Angle grinders, bench grinders, cut-off saws — sparks from grinding can travel over 10 metres (35 feet) and remain hot enough to ignite combustible materials
• Brazing and soldering: Used by plumbers and HVAC trades for copper piping — torches produce open flames near building materials
• Torch-applied roofing: Propane torches used to apply modified bitumen roofing membranes — a frequent cause of construction fires
• Thawing: Using torches or heat guns to thaw frozen pipes or materials — particularly hazardous near insulation and vapour barriers

Any activity that produces temperatures high enough to ignite surrounding materials requires a hot work permit and fire watch on HCMI projects.

4. Hot Work Permit System

The HCMI Hot Work Permit must be completed and authorized before any hot work begins. The permit documents the hazard assessment, fire prevention measures, and fire watch assignment.

Permit Contents

1. Date, time, and specific location of the hot work
2. Type of hot work to be performed (welding, cutting, grinding, brazing, etc.)
3. Name of the worker performing the hot work
4. Name of the designated fire watch
5. Fire hazards identified within 11 metres (35 feet) of the hot work area
6. Fire prevention measures taken (combustibles removed or covered, openings sealed, fire blankets deployed)
7. Fire suppression equipment on hand (type, size, and location of extinguishers)
8. Verification that sprinkler and detection systems (if present) are operational
9. Duration of fire watch after hot work is complete (minimum 30 minutes per HCMI policy)
10. Authorization signature of the HCMI site superintendent or designated competent person

The permit is valid for one shift and one location only. A new permit is required for each shift, each new location, or any significant change in conditions. The original permit is retained in the site trailer; a copy is posted at the hot work location.

5. Fire Watch Duties

The fire watch is a designated person whose sole responsibility during and after hot work is to watch for fires and be ready to respond. The fire watch must:

• Be present during all hot work operations and for a minimum of 30 minutes after the work is complete. HCMI extends the fire watch to 60 minutes after hot work in areas with concealed spaces (wall cavities, ceiling plenums, attic spaces) where smouldering can go undetected.
• Have no other duties during the fire watch. The fire watch cannot perform productive work, operate tools, or leave the area for any reason during the watch period.
• Have a clear view of the hot work area and all adjacent spaces where sparks, slag, or heat could travel.
• Have immediate access to a fire extinguisher (minimum 20-lb ABC type) and know how to use it.
• Have a means to sound the alarm — air horn, radio, or phone to call 911 and notify the site superintendent.
• Know the site evacuation routes and assembly point.
• Attempt to extinguish small fires only if it is safe to do so. If the fire cannot be extinguished immediately with the available extinguisher, sound the alarm, evacuate the area, and call 911.

6. Welding, Cutting & Grinding Fire Prevention

Before starting welding, cutting, or grinding operations:

1. Clear combustibles: Remove all combustible materials within 11 metres (35 feet) of the hot work area. This includes wood shavings, sawdust, paper, cardboard, insulation, polyethylene sheeting, aerosol cans, solvents, and finishes.
2. Protect what cannot be removed: Cover combustible materials that cannot be moved with fire-resistant blankets, welding curtains, or fire-retardant tarps. Wet down combustible floors if practical.
3. Seal openings: Cover or plug openings in floors, walls, and ceilings through which sparks could travel to adjacent areas. This is critical in church construction where open wall cavities and ceiling plenums can carry sparks to concealed spaces.
4. Check below and behind: Inspect the other side of walls, floors, and ceilings where hot work will contact or radiate heat. Metal conducts heat and can ignite combustibles on the opposite side of a steel deck, beam, or partition.
5. Compressed gas cylinders: Secure all cylinders upright with chains or straps. Separate oxygen cylinders from fuel gas cylinders by at least 6 metres (20 feet) or by a non-combustible barrier at least 1.5 metres (5 feet) high with a fire-resistance rating of at least 30 minutes, per O. Reg. 213/91 s.55.
6. Welding screens: Use welding curtains or screens to contain sparks, slag, and UV radiation. This protects adjacent workers and confines sparks to a controlled area.

7. Fire Extinguisher Types

Understanding fire extinguisher classifications ensures the right extinguisher is used for each type of fire:

Class A — Ordinary Combustibles

Wood, paper, cloth, rubber, plastics. The most common fire type on construction sites due to the abundance of combustible building materials.

Class B — Flammable Liquids & Gases

Gasoline, oil, grease, propane, solvents, paints, and adhesives. Common on construction sites where fuels, finishes, and adhesives are used daily.

Class C — Energized Electrical Equipment

Any fire involving live electrical equipment. Once the power is disconnected, the fire becomes Class A or B depending on the fuel.

Common Extinguisher Types on HCMI Sites

• ABC Dry Chemical: The most common extinguisher on construction sites. Effective on Class A, B, and C fires. Contains monoammonium phosphate powder. Available in 5-lb, 10-lb, and 20-lb sizes. HCMI requires a minimum of 20-lb ABC extinguishers for hot work operations.
• CO2 (Carbon Dioxide): Effective on Class B and C fires. Leaves no residue, making it preferred near sensitive electrical equipment and electronics. Not effective on Class A fires as it does not cool the fuel. The discharge horn becomes extremely cold during use — never hold the horn directly.

8. Using a Fire Extinguisher — PASS Technique

Every HCMI worker must know how to use a fire extinguisher. The PASS technique is the standard method:

1. P — Pull the pin. This breaks the tamper seal and unlocks the operating lever. Hold the extinguisher upright.
2. A — Aim the nozzle (or hose) at the base of the fire, not at the flames. The base is where the fuel is burning — aiming at the flames puts the extinguishing agent above the fire where it is ineffective.
3. S — Squeeze the operating lever slowly and evenly. This discharges the extinguishing agent. Release the lever to stop the discharge.
4. S — Sweep the nozzle from side to side at the base of the fire. Continue sweeping until the fire appears to be out. Watch for re-ignition and be prepared to discharge again.

Before Attempting to Fight a Fire

• Ensure the building fire alarm (if active) has been pulled or 911 has been called.
• Confirm you have a clear escape route behind you — never let the fire get between you and the exit.
• Only attempt to fight small, incipient-stage fires (roughly the size of a small wastebasket or smaller).
• If the fire is growing, producing dense smoke, or involves structural elements — evacuate immediately. Your life is more important than the building.
• Most portable extinguishers have a discharge time of only 10-25 seconds. Know the approximate discharge time of your extinguisher.

9. Site Fire Prevention Plan

The Ontario Fire Code requires a fire safety plan for construction projects. The HCMI Site Fire Prevention Plan includes:

• Fire extinguisher locations: Extinguishers are placed at each stairwell, at the site entrance, in the site trailer, adjacent to hot work areas, and near propane storage. A site plan showing extinguisher locations is posted in the site trailer and at the main entrance.
• Evacuation routes: Primary and secondary evacuation routes are established and communicated to all workers during site orientation. Routes are updated as building construction progresses and access points change.
• Assembly point: A designated assembly point is established at a safe distance from the building. All workers report to the assembly point during an evacuation for head count.
• Emergency contacts: 911, the HCMI office (519-509-6363), the site superintendent's cell number, and the local fire department non-emergency number are posted in the site trailer and at the main entrance.
• Housekeeping: Combustible waste (wood scraps, packaging, rags) must be collected and removed from the building at least daily. Oily rags must be stored in closed metal containers — they are subject to spontaneous combustion.
• Smoking: Smoking is prohibited inside the building under construction and within 9 metres (30 feet) of combustible material storage and propane storage. A designated smoking area is established at each site.
• Flammable material storage: Solvents, adhesives, fuels, and other flammable liquids must be stored in approved flammable storage cabinets or in a designated outdoor area away from the building and ignition sources.

10. Temporary Heating Fire Risks

Temporary propane heaters are a significant fire risk on construction sites, particularly during the framing, insulation, and drywall stages when combustible materials are abundant. Key fire prevention measures for temporary heating:

• Maintain a 3-metre (10-foot) clearance from all combustible materials around the heater.
• Never direct the hot exhaust from a torpedo heater toward combustible materials, walls, or stored materials.
• Place heaters on non-combustible surfaces. Protect combustible floors with concrete blocks or steel plates.
• Never leave direct-fired propane heaters operating unattended. Shut them off when workers leave the area.
• Keep propane hoses away from heater exhaust and traffic areas. A damaged hose near a heat source is an explosion risk.
• Ensure temporary polyethylene enclosures are kept away from heater exhaust. Poly sheeting melts and burns readily.

For detailed propane and temporary heating procedures, refer to the Propane & Temporary Heating Safety guide.

11. HCMI Hot Work Procedures

1. Permit Required: No hot work of any kind may begin on an HCMI project without an approved HCMI Hot Work Permit signed by the site superintendent or designated competent person.
2. Pre-Work Inspection: The person performing the hot work and the fire watch must jointly inspect the area within 11 metres before work begins. Both must sign the permit confirming the inspection.
3. Fire Watch Assignment: A dedicated fire watch must be assigned for all hot work. The fire watch may not be the worker performing the hot work. On HCMI projects, the fire watch must carry a radio or cell phone for emergency communication.
4. Post-Work Fire Watch: 30 minutes minimum after all hot work ceases; 60 minutes when near concealed spaces. The fire watch signs off on the permit with the completion time.
5. Extinguisher Requirement: A minimum 20-lb ABC fire extinguisher must be within immediate reach (not more than 7.5 metres) of the hot work area. The fire watch must verify the extinguisher is fully charged before hot work begins.
6. Sub-Trade Compliance: Sub-trades performing hot work on HCMI projects must follow the HCMI hot work permit system. Sub-trades may use their own permits only if they meet or exceed HCMI requirements and are approved by the site superintendent.
7. Sprinkler Systems: Where building fire sprinkler systems or fire detection systems have been partially commissioned, they must remain operational in the hot work area. Sprinkler heads may be temporarily bagged (with fire-watch coverage) only when direct impingement of welding sparks on the sprinkler head is unavoidable. Bags must be removed immediately after hot work is complete.
8. Documentation: Completed hot work permits are retained in the site trailer for the duration of the project and archived at the HCMI head office for a minimum of two years.

12. Hot Work Safety Checklist

Complete before starting any hot work:

• HCMI Hot Work Permit completed and authorized
• Fire watch assigned and briefed — name on permit
• Area within 11 metres inspected for combustible materials
• Combustibles removed or protected with fire-resistant covers
• Floor swept clean of sawdust, shavings, and debris
• Openings in floors, walls, and ceilings sealed or covered
• Opposite side of walls/floors/ceilings inspected for combustible materials
• Fire extinguisher (minimum 20-lb ABC) within 7.5 metres, charged and inspected
• Fire watch has radio or cell phone for emergency communication
• Welding screens or curtains in place to contain sparks
• Compressed gas cylinders secured upright, oxygen and fuel gas separated by 6 metres or barrier
• Sprinkler/detection systems operational (or approved temporary bagging in place)
• Workers aware of evacuation routes and assembly point
• Post-work fire watch duration confirmed on permit (30 or 60 minutes)
• All workers in the area notified that hot work will be performed