Welding, cutting, soldering, and brazing in construction, maintenance, and fabricating activities are considered “hot work” when there is a potential fire hazard present.  Many lives have been lost due to explosions caused by vapors contained in tanks or storage vessels that were ignited by a spark or welders’ torch.  The U.S. Chemical Safety Board has investigated numerous accidents that had been caused when doing this type of work, and found that many companies had not filed for a permit to do the work, or conducted any safety planning beforehand for contract welders and other workers.  Risks involved in performing hot work are asphyxiation, electric shock, air contamination, fire, and explosions. 

When hot work is being performed in confined spaces, such as silos, ship compartments, furnaces, pipelines, vessels, pits, vats, tanks, degreasers, these procedures are essential to ensure the safety of all involved in the work: 

• Have written permit identifying hot work to be done;
• In-depth hazards evaluation of location;
• Safety training in the hazards of hot work;
• Empty and purge tanks beforehand;
• Check tanks, vessels, and pipe for corrosion;
• Test atmosphere for suitable oxygen content;
• Perform gas monitoring;
• Gas detectors should always be used prior to and during hot work;
• Vapors rise as outside temperature warms up, so continuous monitoring is important;
• Keep vents open;
• Be sure valves are leak-free;
• Be sure all power sources are turned off;
• Have NIOSH/MSHA approved breathing devices when required;
• Equipment should never block exits;
• Have constant communication with rescue personnel close-by. 

If there is any doubt regarding the hot work to be performed, a professional environmental specialist should check the air quality and make specific recommendations for the welding/cutting situation.  Special precautions should be taken.  Welders perform all sorts of work on a daily basis.  They know the risks involved and are specialists in their field.  They also understand that there are several types of PPE that they must utilize:

•         Fire retardant welder’s cap;
•         Welding helmet that contains the correct filter shade lens;
•        Gloves that are tough, long-lasting, comfortable, and meet the   needs and hazards of the particular job;
•         Earplugs or muffs in case of loud noise while performing the job, as well as protect the ears from debris;
•        Goggles to protect the eyes. 

Welding is a job that requires much training and skill.  It is up to each company that hires either its own welders or contract welders to ensure their safety at all costs.

Source: CSB

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