Welding Fume Exposure
Managing Occupational Exposure to Welding Fumes
New evidence suggests that a more precautionary approach is needed for welding fume exposure. In the UK there are around 200,000 welders, with around 40% of them working as professional welders and the remainder carrying out welding as part of their job. Welders are exposed to metal fume, ultraviolet (UV) radiation, noise and other hazards. Fume exposure depends on the metal being joined, the welding process, and the circumstances of the work, but levels can be in excess of 10 mg/m3.
In the past, there has been particular concern about the possible cancer risks from welding stainless steel because of possible exposure to hexavalent chromium, a known carcinogenic metal, and tighter levels of control have often been advocated in these circumstances.
Welding Fumes and Cancer
In 2017 the International Agency for Research on Cancer (IARC) concluded that welding fumes are carcinogenic to humans, increasing the risk of lung cancer and possibly kidney cancer. The conclusions on the carcinogenicity of welding fumes were based on a careful review of the human epidemiological evidence and the available animal toxicity data. There are four large high-quality epidemiological studies that were particularly helpful in evaluating the risks for lung cancer. These studies show there is no evidence that the metal or the type of welding process makes any difference to the lung cancer risk. In fact, one of the epidemiological studies showed similar risks for iron oxide fume, regardless of the process generating the fume. The lung cancer risks were apparent for welders who had cumulative exposure equivalent to average levels between 0.2 and 1.1 mg/m3, over a 45-year working life.
HSE Welding Fume Regulations
Based on advice from the Workplace Health Expert Committee (WHEC), the Health and Safety Executive (HSE) have recently advised that the standard of control required for welding fume under the Control of Substances Hazardous to Health (COSHH) Regulations has been tightened. In particular:
- All indoor welding tasks must use local exhaust ventilation and may also require respiratory protective equipment (RPE) to be worn;
- Outdoor welding should only be carried out when wearing RPE.
HSE plan to issue a Safety Alert to provide more detail on the control measures needed for welding.
IOM agrees that no distinctions should be made between different base metals being welded when selecting appropriate control measures, and we endorse the advice from HSE. Our scientists are concerned that the lung cancer risks may apply to all metal fumes, not just welding fumes, and that the acceptable level of exposure may be well below those currently found in the industry. For this reason, we are now advising our customers to ensure that metal fume exposure amongst their workers is as low as technically possible, and certainly less than 1 mg/m3.