The next time you authorize an employee or outside contractor to do welding or metal cutting at your facility, keep this in mind: One loose spark is all it takes to burn down your building. The same goes for other types of "hot work": brazing, grinding, sawing, soldering, thawing frozen pipe, applying roof covering or sealing plastic shrink-wrap by torch.
Hot work fires cause severe, costly property losses. A study by Factory Mutual (FM) of 600 hot work fires at facilities insured by Allendale, Arkwright and Protection Mutual insurance companies revealed that each loss averaged $1.3 million. All were preventable. In most cases, the organization's management could have prevented the problem by enforcing stringent hot work guidelines. Compliance by workers is just as essential. Without partnership between management and workers, there is no guarantee of preventing losses.
You can prevent hot work fires. It's essential to first understand the challenges of the hot work fire hazards at your facility. Training workers, managing contractors and developing a no-nonsense policy enforced by facility management are the first steps. If you're a worker, you need to know what management requires and how to comply. Whether you manage the job or do it, you really can make every hot work job safer. Here's how.
Know the Challenges
The best-prepared companies rehearse potential worst-case fire situations. Almost everything in a building burns. It only takes one spark from a hot work tool to ignite wall and ceiling insulation that can melt, drip in pools and spread fire rapidly. One spark can set off combustible vapors that engulf an area in seconds. Ignited dust particles, if confined, can explode. Sparks can roll and settle on ledges, floor openings, vents or recessed wall or ceiling openings and smolder for hours before igniting surrounding combustible materials. Cutting into an insulated metal wall can ignite the inside wall materials. Insulation around wiring can melt and produce a "smokeless" fire that can do extensive damage for hours before it's detected, and anything combustible on the other side of that wall or close to it can ignite. All it takes is enough heat, with or without a spark.
Training Is Essential
Workers are a company's first line of defense against fires, yet they have been known to fire up hot work tools in volatile areas, such as paint-spray booths, without realizing the danger. The first thing you should explain to them is that skipping one precaution or being unaware of how fires can start places unneeded risk on the business, people's jobs and all workers in the area. Severe fires often result in job losses and, in the case of erring contractors, loss of professional credibility.
Before you start training, select the right people. Appoint a hot work supervisor to make sure employees and outside contractors follow management policies. He or she will authorize the hot work job and make sure the fire watch the worker who monitors the job from start to finish follows all precautions. The fire watch could be one person or a team, depending on the extent of the job and the number of locations where hot work is taking place simultaneously.
Well-trained hot work supervisors should be knowledgeable about fire hazards pertaining to building contents, operations and construction; fully trained in hot work loss prevention supervision and demonstrating good judgment in supervising the fire watch; and available or on call 24 hours a day.
The hot work supervisor should be contacted for all hot work inside and outside of facility buildings. In addition, he or she should be authorized to stop all hot work, required to visit all hot work sites before approving hot work jobs, and should be required to complete a hot work permit authorizing and tracking each hot work job (See sidebar).
Every time he or she receives a hot work job request, the hot work supervisor should consider alternatives to hot work. Is it the only option, or will one of these methods work as well: cutting with hand or electric saw or pipe cutter; using a mechanical way to join items together, such as using nuts and bolts, screwed fittings or couplings; using hand filing, instead of grinding; installing threaded pipe, instead of welded or soldered, where local codes permit; and avoiding use of torches?
If there is no alternative, he or she should tour the proposed hot work site and surrounding and adjacent areas, including adjoining rooms and areas on the floors above and below. Forbid hot work and clearly post "no hot work" signs on equipment having a surface or lining that could be affected by high temperatures, such as metal piping and ducts passing through combustible construction, such as walls, partitions and ceilings. "No hot work" signs also should be posted in areas where the fire hazard cannot be eliminated or controlled, such as stationary machinery producing volumes of heat or flames.
If no practical alternative to hot work is available, the hot work supervisor should clear and prepare a 35-foot (11 m) area surrounding the job. Facility management research shows that this is the minimum safe distance between the hot work activity and anything that could ignite in the surrounding area.
Next, shield combustible flooring with wet sand, fire-retardant tarpaulins or sheet metal, and have the floor in the area swept clean, removing oily deposits and trash. Combustible floors should be wetted down.
Lock out and purge flammable liquids and vapors from containers and piping systems in the area, and properly cover storage containers or other combustibles that cannot be moved out.
Protect or seal openings in floors, walls and ceilings, and block off duct openings because ductwork provides an easy path for sparks to travel or to ignite dust deposits inside the ducts.
In addition, cover or fill any openings in exposed walls, the floor and the ceiling with noncombustible material or Factory Mutual Research Corp. (FMRC)-approved fire-stop material. Move combustibles away from the opposite sides of walls being worked on, and put fire retardant coverings under hot work jobs in such high areas as building framing, ceilings and undersides of roofs. Sparks can settle unseen in those areas and ignite hours later. Fires can ignite under roof areas and where embers have dropped to the floors and ignited.
Close all doors and fire doors, ensuring that no significant gaps are under any door or along its sides. Sparks rolling under a closed door hung close to the floor can ignite outside the hot work area. If this is not possible, use the alternative to the 35-foot (11 m) rule, which is to designate a permanent or temporary area dedicated to hot work, provided the item being worked on can be moved into that area. Screen the area or partition this area from the rest of the facility with noncombustible construction. Never allow it to be used as a temporary storage area.
When the hot work area has been cleared, cleaned and secured, verify that the automatic fire protection systems will remain in service. Appoint only trained personnel to use the portable fire protection equipment.
Bring portable fire extinguishers to immediate and surrounding areas, and lay out fire hoses and charge them. If automatic sprinklers are not installed, alert the local fire department that you will be doing hot work.
Advise the plant emergency response team and security personnel about the hot work activity, including its location and personnel. Assign a qualified fire watch to monitor the hot work area and other areas exposed to stray sparks or heat, including areas not directly visible from the immediate hot work area. Pay particular attention to hot work jobs at elevated locations, on the building roof, on or in building walls and inside buildings with multiple floors. These areas frequently are not watched carefully enough, and often ignite from stray sparks smoldering long after workers have left the job site.
Issue a hot work permit to expire at the end of a shift or eight hours, whichever is shorter, and make sure the permit is clearly visible in the work area.
Assign a trained fire watch to remain at the hot work site for one hour after hot work is completed, and make sure the area is monitored for an additional three hours. Many fires start hours after workers have left the property.
Confirm that automatic smoke detection have been installed throughout the hot work area and that they have been arranged properly and alarmed to a constantly attended location. A fire watch, an alternate or a security guard also can be assigned to monitor the area.
Finally, reinspect the hot work area and surrounding space at the end of the monitoring period. If all is safe, sign the permit to signify the area is safe and remove it from the area. Keep it for a record.
The Importance of a Fire Watch
The fire watch must know how to use fire extinguishers and charged fire hoses and how to sound the fire alarm. To monitor the area effectively:
- Stay near the person doing the hot work, close all fire doors, make sure the work area remains free of combustibles and verify that fire retardant tarpaulins are not moved.
- Never leave the area during the job or take breaks, such as lunch, unless relieved by a qualified replacement.
- Stop the hot work if improper conditions develop.
- Be ready to sound the alarm and use an extinguisher or fire hose if a fire starts.
- Check the hot work area and adjacent areas (on the same floor and floors above and below the work area) for four hours after the work has ended, then sign the permit.
More than half of all hot work fires and the resulting property damage are caused by outside contractors. One of management's most important functions is to hold them responsible for following the organization's policies. Don't assume contractors understand the importance of safety. Although they may have the technical expertise to do hot work, they might not understand the severe risk that hot work creates and the steps needed to effectively manage this hazard.
Contractors generally are not aware if an organization has a hot work policy. They must be told. Make sure they understand that your policies must be followed, or they could face potential contract termination. They should demonstrate that they can conduct hot work safely. If you have doubts, have the hot work supervisor provide instruction.
It's also important to take these steps in advance:
1. Get references from previous customers of the contractors you are considering.
2. Discuss the planned work with contractors. Find out about their expertise and concern for the hazards at the work site and surrounding environment.
3. Make sure bids and contracts state your policy clearly. A few days before the contractor begins the job, inform it in writing of its responsibilities for following your hot work policy.
4. Confirm that the contractor has proper insurance.
5. Do not sign any hold-harmless clause created by the contractor.
6. Do not waive your company's subrogation rights.
Take Your Program's Pulse
Once you understand the dangers inherent in hot work operations and the training needed to deal with them, you're ready to write the policy stating management's intention to control hot work. Send it to employees and contractors. The policy may cite detailed loss prevention procedures or refer to another source such as a policy manual that contains those procedures. If they reflect the items cited in this article, you're off to a good start in preventing hot work fires.
If you do it right, you will be able to measure your success by the loss that never happens. Effective property loss prevention is no accident.
Mark Blank is a standards engineer with Factory Mutual's Mid-West Operations. He holds an A.A.S. in fire science technology from the College of DuPage, Glen Ellyn, Ill., and a B.S. in fire science services from Southern Illinois University, Carbondale, Ill. His engineering specialties include hot work application in various industries and arson investigation.