Whether you’re a large, heavy equipment manufacturer with a stable of experienced welders or a small job shop where welding equipment is used infrequently, odds are you use the same type of equipment: a metal inert gas (MIG) welder.

This kind of welder is by far the most common and most versatile welder, adaptable not only to many different user skill levels but also to many different materials and applications. It’s important to know the hazards MIG welding poses and ensure that you protect workers against them.

Hazards of MIG welding

A MIG welder is a type of shielded metal arc welder that uses high-voltage electricity to melt and form a metal wire that’s fed through the welding torch and applied to the point of the weld. When cool, the metal forms a bond between the two welded objects.

To protect the weld from oxidation, an inert shielding gas is typically fed through the torch that protects the welding zone. In another variation, the shielding gas is generated by a coating on the wire itself (flux-cored wiring), but the arc and the gas shield are characteristic of all MIG welding.

As you might expect, the combination of an electrical arc, hot metal, and gases poses a range of hazards to welders and other workers in the area, including:

Fire hazards. Welding is just one variety of “hot work,” or work involving active use of an ignition source. If you have an ignition source and breathable air—two legs of the “fire triangle”—you must take care not to have the third leg (flammable and combustible materials) present.

Respiratory hazards. Welding comes with multiple respiratory hazards. The metal being welded, the filler material being used, and any substances on the surface of the object being welded (such as paint) can be vaporized, creating toxic smoke and fumes. The inert gas used to shield the arc can accumulate in the work area, displacing oxygen. The process can also generate carbon monoxide gas at potentially toxic levels.

Eye and skin burns. The bright, hot arc that melts the metal wire is dangerous to look at directly, capable of causing burns to the cornea (the outer membrane of the eye). This hazard affects welders and anyone in the area who can see the weld zone.

The ultraviolet light generated by the arc can cause sunburn. Drops of melted metal splashed and sprayed from the weld zone can burn exposed skin, and the workpiece itself will be hot to the touch for some time after the weld is completed.

Ergonomic hazards. Welders often position their torch and workpiece with their helmets raised and then jerk their heads to snap the helmet closed as they light the torch.

Repeated frequently over a long period of time, this motion can lead to repetitive motion injuries in welders.

In addition, workpieces that are not optimally positioned or job tasks that require welders to contort their bodies can contribute to ergonomic injuries.

Protect Workers from the 5 Most Common Hazards of MIG Welding

A 48-year-old shipyard welder was welding on a barge that was undergoing renovation, working from an elevating work platform. A pinhole leak developed in the hydraulic lines on the lift, and the escaping hydraulic oil was ignited by sparks from the welding operation. The worker was taken to a burn unit, but later died.

Yesterday, we talked about the four most common hazards of MIG welding—including fires, respiratory hazards, burns, eye injuries, and ergonomic injuries. Today, we’re going to talk about control mechanisms that can be used to minimize the risk from each of those hazards.

Protecting welders and other workers

To protect themselves and others against welding hazards, it’s essential that welders take appropriate precautions.

Fire prevention. Welders should clear the work area of all flammable and combustible materials and always have a fire extinguisher readily available. If flammable and combustible materials cannot be removed from the work area, welders should use a combination of barriers, a fire watch, and hot work permitting to control fire hazards.

Respiratory protection. Reduce workers’ exposure to toxic fumes during welding by:

  • Cleaning the workpiece to remove any paint, solvent residue, or other substances that could generate toxic smoke and fumes;
  • Providing good, general ventilation in the work area and training workers to position themselves to avoid vapors generated by welding;
  • Using local exhaust ventilation to remove contaminants from the work area; and
  • Providing respirators if ventilation and positioning cannot reduce air contaminants to safe levels.

Burn prevention. Welders should wear protective, flame-resistant gloves (such as leather welder’s gloves) insulated to provide protection from heat and having gauntlet cuffs to provide arm protection. Other protective clothing can include fire-retardant coveralls or aprons and leather boots or shoes. Workers should avoid synthetic materials like polyester and nylon that can melt to the skin when exposed to high temperatures.

Eye injury prevention. You must protect the eyes of the welder and any other workers in the area from the welding arc, flying sparks, and droplets of hot metal. You can use welding blinds to shield the work area from surrounding areas.

For welders, the welding hood protects the eyes from physical damage and burns. The lens shade built into a welder’s hood damps the light of the arc so the welder can see the weld zone without risking eye damage. Lens shades come in different filter strengths, rated from #8 to #13, and should be chosen based on the amperage used for welding.

Ergonomic injury prevention. To prevent ergonomic injuries, minimize welders’ tendency to close their welding hoods by jerking their heads. For workers who do not often need to lift and lower their hoods, it may be enough to train them to use their free hand to lower their hoods. For welders who do need to raise and lower their hoods often, consider providing hoods with autodarkening lenses that will lighten when the welding arc is shut off and darken quickly when the arc is activated.

To prevent ergonomic injuries related to positioning and posture, give workers control over the layout and arrangement of their workstation and workpiece wherever possible, using adjustable worktables and workstations.

For more information or assistance with your Environmental and Health & Safety regulatory compliance needs, contact Ralph Carito at Total Environmental & Safety, LLC (Total) at rcarito@TotalEnviron.com or 908-442-8599.