Beyond following the regulations mandated by OSHA and your state, safety in welding is largely based on understanding hazards and awareness of your surroundings. Welding hazards can be roughly broken into seven risk categories:
Arc welding is based on the creation of an electrical circuit, and a “break” in the electrical circuit, where the electricity is forced to travel through a gas (that becomes ionized in this process). The resistance in gas (think about the difficulty electricity has traveling through air) creates an “arc.” An arc is comprised of electrical energy lost as heat and light, so electrical hazards may be the most intuitively recognizable risk in arc welding. Common electrical hazards include:
Work pieces can be hot, and this may not always be visually apparent. To reduce the risk of burns, allow pieces that have been welded or cut adequate time to cool. Also, sparks from the welding process are hot metal and can burn arms or exposed skin, as well as eyes. Proper PPE, including closed-toe shoes, safety glasses with side shields under a welding helmet, welding jackets and covering exposed skin, can help the welder avoid burns.
Arc welding, plasma welding and cutting, and oxyfuel welding and cutting all produce light. Eyes are best protected from UV and visible light emission of arc welding by means of a welding helmet. Different shades of lenses are available as appropriate for different welding processes and currents. Welding shades generally vary between 8-12, although auto-darkening helmets can have variations between 7-14. If you are not sure what lens shade you need, see your welding distributor. Newer auto-darkening helmets utilize lenses that protect from UV (ultraviolet) and IR (infrared) light even when not darkened. Other employees working near a welder should also be protected with welding screens. Oxyfuel welding should use at least Shade 5 goggles.
Another risk related to the light from arc welding is burns to the skin akin to rapid sunburn. Use proper PPE to make sure no skin is exposed.
Finally, many experienced welders “tack,” or create small welds to hold pieces in place for welding - oftentimes this is done without the use of their welding helmet. An auto-darkening helmet, which allows the end user to manipulate pieces with the helmet down, is a great option to consider for welders who ‘tack’.
Maintaining a workspace free of flammability hazards such as oily rags is one of the best ways to reduce risk of fire. Butane lighters should not be kept in the welder’s pocket or on the welder’s person, and oxygen should never be used to clean the welder’s clothes or introduced into the welding area. Even vapors from gasoline or other chemicals can create flammability risk and should be kept away from the area. Remember, sparks can fly from the welding area into the surrounding area and present a risk for anything flammable in the nearby vicinity.
Welding or cutting a tank that once contained something flammable or an unknown chemical is not advised.
Asphyxiation robs your body of sufficient oxygen to live. If other gases displace oxygen out of the area or decrease the percentage of oxygen in the air, a welder would still have “air” to breathe, but if this air is depleted of oxygen, asphyxiation can take place quickly and without warning.
Never weld in a confined space without supplied breathing air. Be aware that cylinders left open or liquid cylinders releasing pressure through a relief valve can introduce gas into the area that can displace oxygen and cause asphyxiation. Allow for lateral airflow into the welding through open doors and use of fans.
Some materials - for example, coated materials and stainless steels - can create toxic fumes. Know the base metal you are welding and associated hazards. Remove oils and other foreign chemicals that can be vaporized when welding, prior to heating the piece. Different filler metals and electrodes can have their own unique risks. Some tungsten can contain thorium, which is a radioactive element. This can present a hazard in the grinding area where dust can be inhaled.
The risks associated with compressed and liquefied gases vary and can include, but are not limited to, flammability, risk of explosion and risk of accelerating combustion and temperature. Gases should be stored in a way that complies with the National Fire Protection Association (NFPA) standards as well as all applicable CGA (Compressed Gas Association) standards.
Nine steps to welding safety: Consider your surroundings