As a result of The International Agency for Research on Cancer (IARC) releasing new scientific evidence that exposure to mild steel welding fume can cause lung cancer and possibly kidney cancer in humans, mild steel welding fume has been reclassified as a human carcinogen by the Workplace Health Expert Committee.
The Health and Safety Executive (HSE) has therefore released a safety alert for those undertaking welding activities, including mild steel, in any industry. In order to protect workers, the HSE is strengthening their enforcement of cancer-causing welding fumes with immediate effect.
Mary Cameron, occupational hygiene team leader, gives an overview of the changes and why control measures are fundamental to protecting employee health and safety.
Welding Fume Contents and Risks
Welding fume is a complex and varying mixture of airborne particles, vapours and gases which arise from the thermal manipulation of metal materials. The fume particles formed from the vaporisation of molten metal as well as by-product vapours and gases may cause a wide range of adverse health effects. Welding on painted, plated, galvanised or degreased metals may cause additional inhalation exposure concerns.
Depending on the job’s specific circumstances, physical hazards should also be considered such as heat stress, EMF and noise exposure. As with any hazardous process, all aspects should be considered when undertaking the risk assessment and control measures implemented accordingly to reflect the level of risk.
"welding on painted, plated, galvanised or degreased metals may cause additional inhalation exposure concerns"
What control measures do I need to implement?
It must be understood that general ventilation does not achieve the essential welding fume exposure control. Control of exposure to carcinogenic fumes requires more effective engineering controls, such as local exhaust ventilation (LEV), which allows for at-source fume extraction thus preventing welding fume from spreading into the surrounding workplace and entering the worker’s breathing zone.
Indoor welding tasks require the use of LEV. If LEV is unable to control fume capture then Respiratory Protective Equipment (RPE) is also required. Appropriate RPE should be also provided for welding outdoors. Regardless of the duration of exposure, the HSE will no longer accept any welding undertaken without suitable exposure control measures in place as there is no known level of safe exposure. Adequate exposure control measures are a necessity and for good reason.