There is new scientific evidence from the International Agency for Research on Cancer that exposure to mild steel welding fume can cause lung cancer and possibly kidney cancer in humans. The Workplace Health Expert Committee has endorsed the reclassification of mild steel welding fume as a human carcinogen.
With immediate effect (from February 2019) there is a strengthening of the Health and Safety Executives’ enforcement expectation for all welding fume, including mild steel welding; because general ventilation does not achieve the necessary control.
Control of the cancer risk will require suitable engineering controls for all welding activities indoors e.g. Local Exhaust Ventilation (LEV). Extraction will also control exposure to manganese, which is present in mild steel welding fume, which can cause neurological effects similar to Parkinson’s disease.
Where LEV alone does not adequately control exposure, it should be supplemented by adequate and suitable Respiratory Protective Equipment (RPE) to protect against the residual fume.
Appropriate RPE should be provided for welding outdoors. You should ensure welders are suitably instructed and trained in the use of these controls.
Regardless of duration, the Health and Safety Executive will no longer accept any welding undertaken without any suitable exposure control measures in place, as there is no known level of safe exposure.
Risk assessments should reflect the change in the expected control measures.