The HSE will no longer permit welding to be carried out without any suitable control measures in place, regardless of duration. Control measures will range from ventilation to suitable respiratory protective equipment (RPE), depending on the nature of the activity.
The change in advice, set out in a new HSE alert, reflects new scientific evidence from the International Agency for Research on Cancer that exposure to all welding fume, including mild steel welding fume, can cause lung cancer and possibly kidney cancer. HSE's Workplace Health Expert Committee has therefore endorsed the reclassification of mild steel welding fume as a human carcinogen.
Companies and contractors carrying out welding activities must also update their risk assessments to reflect the change in expected control measures, HSE said.
Health and safety law expert Sean Elson of Pinsent Masons, the law firm behind Out-Law.com, said: "The recognition that all welding fume can cause cancer is an important development, and businesses can expect the HSE to rigorously enforce based on the expectations for engineering controls."
Welding fume refers to the mixture of airborne gases and very fine particles given off during welding and hot cutting processes. The danger to human health comes if these gases and particles are inhaled.
The HSE will now require "suitable engineering controls" for all indoor welding as a first step to control the cancer risk from steel welding fume. Effective local exhaust ventilation (LEV) may be used to carry away the gases and particles before they can be breathed in. Extraction will also control exposure to manganese, which is present in mild steel welding fume and may cause neurological effects similar to Parkinson's disease, the HSE said.
If LEV or similar measures alone will not adequately control exposure, "adequate and suitable" RPE should also be used to protect against the residual fume. Appropriate RPE should also be provided for welding outdoors. Welders should be suitably instructed and trained in the use of these controls, the HSE said.
Engineering controls must be correctly used, suitably maintained and subject to thorough examination and test where required. RPE must be subject to an RPE programme incorporating training, maintenance and supervision requirements.
Health and safety expert Jon Cowlan of Pinsent Masons said: "Employers should review their COSHH [Control of Substances Hazardous to Health] assessments as a matter of priority - and should not forget 'non-core' activities either, such as in-house engineering workshops and contractors visiting site."