Hot work continues to be one of the most significant industrial hazards facing the world. But with the help of longstanding and recently updated resources from NFPA®, the fire and life safety risks associated with hot work can be significantly reduced.
What is hot work?
Hot work refers to any process that involves open flames, sparks, or heat-producing tools and equipment. This can include activities such as welding, cutting, brazing, soldering, grinding, and other similar processes that generate heat and sparks. Hot work processes have the potential to ignite flammable materials, gas, or vapors in the surrounding environment, leading to fires or explosions if proper precautions are not taken.
Between 2017 and 2021, fire departments in the United States responded to an estimated average of 3,396 structure fires involving hot work each year, according to the latest data from NFPA. These fires caused an estimated yearly average of 19 civilian deaths and 120 civilian injuries.Statistics on hot work–related injuries and deaths to workers paint an even grimmer picture. According to the Bureau of Labor Statistics, more than 500,000 workers are injured in welding accidents alone each year, and the U.S. Chemical Safety and Hazard Investigation Board has found that hot work is one of the most common causes of worker death among incidents that it investigates.
SOURCE: NFPA Research
This year alone, there have been multiple incidents involving hot work, some fatal. In April 2023, two people were injured in Missouri when a metal drum they were cutting into exploded. A month prior, a firefighter in Buffalo, New York, was killed in a four-alarm fire where there was a partial building collapse due to a fire that started from workers handling torches in the area. Internationally, a fire that was started by welding sparks left 29 people dead in Bejing in April.
What are the associated hot work fire hazards?
When you are performing hot work, there is potential to bring together the three parts of the fire triangle: oxygen, fuel, and an ignition source. There is oxygen present in all spaces where workers perform hot work — the air we breathe is made of 21 percent oxygen under normal conditions. Special consideration should be given around sources of pure oxygen, such as oxygen tanks, which could elevate the oxygen concentration in the air, increase the potential for materials to ignite, and greatly contribute to the intensity of any fires that start.
Potential fuel sources include all materials which could be ignited, such as construction materials, insulation, roofing materials, ignitable (flammable and combustible) liquids, gases, paint, cleaning solvents, as well as simple combustibles in the area like rags, paper, wood, dust, cardboard, and furnishings. Another fuel source that is often overlooked is the item that hot work is performed on. If not monitored properly, the hot work could create enough heat to ignite that item.
Lastly, the ignition source is as simple as the hot work itself. This can occur through direct application with flames or sparks from welding, cutting, and burning. Ignition can also occur through indirect application where heat is radiated through the air or conducted through metal surfaces to fuel sources nearby.
What are methods to minimize fire hazards?
An effective process to minimize fire hazards includes three simple steps: recognize, evaluate, and control. The first step is to recognize the type of hot work that is to be performed and potential fuel hazards that might be present in the work area. The second step is to evaluate what hazards are present and the likelihood of the fuel and ignition sources coming together based on the type of hot work. Finally, the third step is to control the hazards by taking appropriate steps to eliminate or minimize the fire risk.
Furthermore, all hot work should be properly permitted before it is started. The act of competing a proper hot work permit form will ensure that the recognize, evaluate, and control steps are followed and formally documented.
Solutions from NFPA
NFPA offers hot work safety resources in the form of both codes and standards and online training.
Nearly 60 years ago, NFPA released the first edition of its hot work standard, NFPA 51B, Standard for Fire Prevention During Welding, Cutting, and Other Hot Work. OSHA values the benchmarks set by the standard so much that they incorporated it into general industry regulations for welding, cutting, and brazing (29 CFR 1910.252). The standard is also referenced in other notable NFPA documents such as NFPA 241, Standard for Safeguarding Construction, Alteration, and Demolition Operations. NFPA 51B provides guidelines for conducting hot work safely, including measures to prevent the ignition of combustible materials, and proper qualifications for personnel performing hot work, fire watch and appropriate use of fire-resistant materials and equipment, along with training and qualifications for personnel performing hot work, fire watch, and appropriate use of fire-resistant materials and equipment.
Recently, NFPA updated the Hot Work Safety Certificate Online Training (also available in Spanish). The training provides attendees with in-depth knowledge of identifying and reducing hot work hazards, and is ideal not only for individuals who will be performing hot work, but also those issuing hot work permits and anyone responsible for fire safety on a site where hot work will be performed.
Simply put, hot work fires can result in avoidable death, injury, and property loss. Hot work introduces an ignition source where one would not normally be, increasing the potential for a fire. Therefore, the top safety recommendation is to determine whether there is an alternative to hot work. By avoiding hot work, the risk of an unintended fire is minimized. However, the reality for most industry sectors is that hot work is necessary and unavoidable to complete many construction and repair projects. So, to ensure that hot work is performed safely, all parties involved need to understand the governing requirements, associated hot work hazards, and methods to minimize fire hazards through completing a training such as the Hot Work Safety Certificate Online Training. When everyone follows safe hot work practices, the chance of a deadly hot work fire is drastically reduced.
Important Notice: Any opinion expressed in this column (blog, article) is the opinion of the author and does not necessarily represent the official position of NFPA or its Technical Committees. In addition, this piece is neither intended, nor should it be relied upon, to provide professional consultation or services.
NFPA Senior Chemical Engineer Matthew Barker also contributed to this blog.