According to the Occupational Safety and Health Administration (OSHA), the definition of “hot work” is riveting, welding, flame cutting or other fire or spark-producing operations. A wide range of industries require their employees to perform hot work activities in order to reduce downtime and keep their businesses thriving through the maintenance of equipment. Along with these actions comes the risk to the health and safety of the workers. In a given year, there is an excess of 500,000 workers at risk from the numerous hazards inherent to hot work procedures. Welding, cutting and brazing techniques pose some distinctive hazards to employees. These range from fire and explosion to air contamination to eye exposures. Injuries can range from minor burns to fatal incidents.

One safety hazard associated with hot work is potential exposure to ultraviolet (UV) radiation during the arc welding process. This method can result in burns to the skin and damage to the lens of the eye. Excessive UV exposure to the eye can result in a condition known as “welder’s flash” which gives the feeling of having coarse particulate in the eye. This condition often shows up hours after the exposure has occurred. Current regulations require the use of personal protective equipment (PPE) such as welder’s goggles or helmets with special glass of varying tints, fire retardant clothing and welding gloves. In addition, UV light can sensitize the skin, increasing the potential damage from certain hazardous chemicals.

Infrared radiation (IR) also can be generated by the electric arc welding process or other flame cutting procedures and can cause thermal burns to the skin. The proper use of personal protective clothing can guard against injury if maintained in good condition and worn properly and consistently.

Exposure to the intense visible light emitted by an electric arc can cause damage to the retina due to “viewing" of the arc. At no time should the welding arc be observed without eye protection. Welding screens can be used to separate the workers performing the welding from individuals in adjacent areas.

Compressed gases used as a component of hot work processes pose a number of potential hazards to the user. Depending on the application, gases may be corrosive, explosive, flammable and noxious or may displace the oxygen in the atmosphere of the work area. It is imperative the contents of the cylinder are identified, labeled and stored appropriately. The caps for most compressed gas cylinders are compatible; therefore you should not rely on the label on the cap to identify the contents of the cylinder. Compressed gas cylinders should be secured at all times with straps or chains to prevent them from falling. If regulators are broken off during a fall, a cylinder can become a missile. These “rocket” cylinders have been shown to penetrate concrete walls and cause extreme damage, including fatalities.

Cylinders should be stored with signage posted in the area identifying specific PPE, along with information about reactivity and work practices. When cylinders are transported, they should be firmly capped and secured to a cart prior to any movement. Flash back arrestors or flame arrestors should be used in oxy-acetylene welding and cutting procedures in order to keep the flames from traveling back through the equipment and causing an explosion with potential disintegration of the tank.

In addition to the safety issues with hot work processes, there also is a health concern associated with the fumes generated from welding, cutting and brazing events. It is important to determine the contaminants of the process prior to conducting the work. The substrate on which you are performing work or the process itself may contain hazardous materials which are released as respirable fumes. This airborne particulate can be inhaled by the employee performing the procedure. Metals such as lead, cadmium and zinc can be generated when welding on galvanized materials. Welding on stainless steel can generate chromium and nickel fume, which are considered to be human carcinogens.

The health effects of hot work exposures range from irritation of the respiratory tract to poisoning of the whole body. Disease caused by metal particulate in the lungs, known as pneumoconiosis, can result from hot work procedures without the use of respiratory protection or ventilation. In order to determine if these exposures exist, air quality monitoring should be performed during a normal work shift. A sampling pump, fitted with a filter cassette and calibrated to a specific flow rate, is attached to the employee with the open cassette in the breathing zone. The sampling will continue throughout the work shift. At the completion of the shift, the sample is capped and sent to a certified laboratory for analysis. The results are then compared to the OSHA permissible exposure limits (PELs) for each component to determine if any overexposures exist.

The development of a comprehensive written program to manage your hot work process is essential.   The plan should include information about PPE, a hot work permitting process, cylinder storage, transport and handling, flash back arrestor use, respirator requirements (if any) and air quality monitoring. The safety and health of your workers may depend on it.