Fire Protection, Prevention, Hot Work, and Alarm Response
Key Takeaways
- Fire prevention controls fuel, ignition sources, oxygen exposure, and housekeeping before a fire starts.
- Hot work requires permits, area preparation, fire watch, suitable extinguishers, and post-work monitoring.
- Workers should use extinguishers only for incipient fires when trained, safe, and able to exit.
- Alarm response depends on immediate warning, evacuation, accountability, and notification of responders when needed.
Fire Protection, Prevention, Hot Work, and Alarm Response
Construction Fire Risk
Fire protection is harder during construction because permanent alarms, sprinklers, fire doors, exits, and standpipes may be incomplete or impaired. At the same time, the site may contain temporary heaters, generators, extension cords, fuel, adhesives, roofing materials, packaging, welding, cutting, and grinding. A CHST should evaluate fire protection as an active system that changes with each phase of work.
Fire prevention controls the fire triangle: fuel, oxygen, and heat. Good housekeeping removes scrap, oily rags, sawdust, and packaging. Electrical inspections find damaged cords, overloaded circuits, and blocked panels. Flammable liquid controls include approved containers, closed lids, bonding and grounding when needed, and storage away from exits and ignition sources. Fire lanes, hydrants, extinguishers, standpipes, and alarm points must remain accessible.
Prevention Controls and Hot Work
A fire prevention plan should identify major fire hazards, ignition sources, material storage rules, emergency equipment, and responsible personnel. On multi-employer sites, coordination matters because one contractor's sparks can ignite another contractor's materials.
| Control area | Good practice | Red flag |
|---|---|---|
| Housekeeping | Daily debris removal | Combustibles near heaters |
| Electrical | Inspect cords and panels | Daisy-chained cords |
| Liquids | Approved containers | Open cans near exits |
| Access | Clear fire lanes | Materials blocking hydrants |
Hot work includes welding, cutting, brazing, soldering, grinding, torch-applied roofing, and similar heat-producing tasks. A hot work permit should verify that the area was inspected, combustibles were removed or protected, floor and wall openings were covered, the correct extinguisher was present, and a fire watch was assigned when needed. The fire watch must know how to stop work, sound the alarm, use available equipment if trained, and stay after the work for the required monitoring period.
Special concern is needed near concealed spaces, shafts, insulation, combustible dust, chemical storage, and roofing assemblies. Sparks can travel beyond the visible work area and start a smoldering fire that appears after crews leave.
Alarm and Extinguisher Response
When an alarm sounds, workers follow the EAP: warn others, evacuate or shelter as directed, and report for accountability. Portable extinguisher use is limited to incipient fires when the worker is trained, the correct extinguisher is available, the alarm has been activated, and a clear exit remains behind the worker. If smoke, heat, rapid spread, chemicals, explosion risk, or blocked egress exists, workers should evacuate and call emergency services.
Extinguishers must match the hazard. Class A is ordinary combustibles, Class B is flammable liquids, Class C is energized electrical equipment, Class D is combustible metals, and Class K is cooking media. PASS, meaning pull, aim, squeeze, sweep, is only a technique; it does not make an unsafe fire safe to fight.
- Inspect extinguishers for access, pressure, pin, seal, and damage.
- Replace or recharge used extinguishers immediately.
- Use fire watch or other compensating measures during impairments.
- Notify affected parties when alarms, sprinklers, or standpipes are out of service.
A welder will cut steel near a wall opening leading to a shaft with packaging debris. What should happen before work begins?
Which fire may be appropriate for trained employee extinguisher use?
Why must fire lanes and hydrants remain clear?