The International Agency for Research on Cancer (IARC) has updated its classification for welding fumes and UV radiation from welding to Group 1 carcinogens, the agency’s designation for agents that carry sufficient evidence of carcinogenicity in humans.
A previous IARC assessment done in 1989 classified welding fumes and UV exposure in Group B as “possibly carcinogenic to humans.”
In March, a group of 17 scientists from 10 countries met to reevaluate the risk welding fume exposure presents to people based on new evidence that has since accumulated from observational and experimental studies.
In a report published in May's The Lancet Oncology, researchers found that arc welding generates UV radiation: a risk factor for various cancers of the eye and eye burns.
Welding fumes were also found to increase the risk of lung cancer, and to some degree kidney cancer and chronic inflammation. Researchers also noted that solvents used for cleaning metal in tandem with welding, such as trichloroethylene, showed an increased risk for kidney cancer.
OSHA's suggestions to reduce exposure to welding fumes include:
- Welding surfaces should be cleaned of any coating that could potentially create toxic exposure, such as solvent residue and paint.
- Workers should position themselves to avoid breathing welding fume and gases. For example, workers should stay upwind when welding in open or outdoor environments. General ventilation, the natural or forced movement of fresh air, can reduce fume and gas levels in the work area. Welding outdoors or in open work spaces does not guarantee adequate ventilation. In work areas without ventilation and exhaust systems, welders should use natural drafts along with proper positioning to keep fume and gases away from themselves and other workers.
- Local exhaust ventilation systems can be used to remove fume and gases from the welder’s breathing zone. Keep fume hoods, fume extractor guns and vacuum nozzles close to the plume source to remove the maximum amount of fume and gases. Portable or flexible exhaust systems can be positioned so that fume and gases are drawn away from the welder. Keep exhaust ports away from other workers.
- Consider substituting a lower fume-generating or less toxic welding type or consumable.
- Do not weld in confined spaces without ventilation. Refer to applicable OSHA regulations
- Respiratory protection may be required if work practices and ventilation do not reduce exposures to safe levels.
NIOSH offers many resources for welders seeking information on protective gear and best safety practices.