Mild Steel Welding Fume - 2019 COSHH Control Measures


Before we get into COSHH Control Measures for Mild Steel Welding Fume, we probably best start with what Mild Steel Welding Fume actually is.

It’s a complex mixture of airborne particles, gases, fumes and vapors that form from the thermal manipulation of metals.

The welding fume particles created from the vaporisation of molten metal can cause a wide range of adverse health effects.

The International Agency for Research on Cancer (IARC) has very recently revealed a new scientific paper. The paper cites evidence that exposure to mild steel welding fume can cause lung and kidney cancer. Therefore The Workplace Health Expert Committee has reclassified mild steel welding fume as a human carcinogen. 

Welding remains one of the most common activities carried out within industry throughout the UK. The Health and Safety Executive (HSE) will therefore no longer allow welding to be performed, without suitable COSHH control measures in place. Partly due to there currently being no known level of safe exposure, regardless of duration.

The stricter enforcement measures come after the IARC evidence showed that general ventilation also does not achieve the required control.



The inhalation of mild steel welding fume has been known to be hazardous to health for some time, even before the most recent HSE announcement.

Welders are more prone to reduced lung function, lung infections and many experience irritation of the throat and lungs. Welders can also experience flu-like symptoms after welding activity (also known as ‘metal fume fever’). The causes are commonly related to welding on plated, galvanised, painted or degreased metals as well as mild steel. These may cause additional inhalation and respiratory exposure concerns as mentioned previously.

Exposure to manganese can also cause adverse health effects including neurological effects similar to that of Parkinson’s disease.

Welding of stainless steel may produce nickel oxide and chromium oxide, both of which can cause asthma. Stainless steel fume may also contain hexavalent chromium which is known to cause more severe lung cancer.



The HSE has released a safety alert for all undertaking welding activities, including mild steel, in any industry. In order to protect workers, the HSE is strengthening its enforcement of cancer-causing welding fumes with immediate effect. 

The latest Regulation 7 (5) of COSHH sets out a very clear requirement for the control of both mutagenic and carcinogenic substances. It is the responsibility of the employer to ensure that exposure is reduced to as low as is reasonably practicable, as stated within welding fume regulations.

The control of cancer risk will require suitable engineering and COSHH control measures for all welding activities that take place indoors, which includes Local Exhaust Ventilation Testing. Employers are also being warned that where LEV alone does not adequately control exposure, it should be supplemented with suitable respiratory protective equipment. This RPE should be used to protect employees from any residual fume. Even when welding outdoors, employers should provide appropriate RPE.

Health and safety law expert Sean Elson of Pinsent Masons added: “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.”

The raised enforced control standards are highlighted below:

  • Outdoor welding requires the use of RPE
  • All forms of welding fume can cause cancer
  • Enforcement of the raised control standards (COSHH Regulation 7) is with immediate effect 
  • Indoor welding requires the use of LEV. If LEV is unable to control fume capture then RPE is also required



The Institution of Occupational Safety and Health (IOSH) recommends that all members and industry employers in the UK. Due to the changes to the control standards for welding fume. Review all current welding control measures in place to ascertain they meet all raised control standards. This may also mean that COSHH risk assessments and risk registers may need to be updated.

The changes currently only affect the UK. For companies outside of the UK, we predict local regulators may also begin to extend their enforcement position in the near future due to the evidence being from the IARC.

The HSE stresses that all welders within industry are required to be suitably trained in the use of all controls.



ECL Occupational Hygienist Mike Mullet says. “We are advising our clients to review all relevant COSHH risk assessments as a matter of priority.”

“It is also important to remember facial hair,” says Mike. “Although a fashionable beard is currently on-trend in the UK, RPE can often cause some incompatibility issues. That’s why we stress that it doesn’t matter if you opt for the Viking style or just designer stubble. All welding workers need to be clean-shaven to ensure a good, tight seal with their respirator.”

The HSE has provided specific guidance on the control measures to consider when welding in a variety of environments. In all cases, RPE with a minimum Assigned Protection Factor (APF) of 20 is outlined as required. As always, the RPE should be suitable and correct for the workforce who will be wearing it.

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 allows for at-source fume extraction. Preventing mild steel welding fume from spreading and entering the worker’s breathing zone or into the workplace.

In summary, we advise all employers to ensure the following measures are put in place for any welding activities:

  • An up to date LEV Test has been done
  • Ensured correct use and selection of RPE
  • COSHH Risk Assessments and risk registers updated
  • Appropriate Training has been given to all employees
  • Current welding control measures have been reviewed



Physical hazards should also be evaluated, such as heat stress, EMF and Workplace Noise Exposure depending on the job’s specific circumstances. All aspects should be considered when undertaking risk assessments, and control measures should be implemented accordingly to reflect the risk level.

If you are welding mild steel, we recommend updating your COSHH risk assessment and adapt any exposure controls previously in place. This will ensure the provision of suitable control measures moving forward.



ECL’s highly experienced occupational hygienists can evaluate the risk of exposure of hazardous agents in the workplace, including welding fume. The aim is to ensure complete COSHH compliance via effective COSHH control measures.

For 18 years, our occupational hygiene department has serviced many industries offering the risk of welding fume exposure. We have attended many of these sites to undertake Workplace Exposure Monitoring among our many other air quality, occupational hygiene or environmental consultancy services.

ECL can assess employees’ exposure to hazardous substances via comprehensive exposure monitoring. This will determine the levels of substances in the workplace. ECL can ensure workplace exposure limits are not exceeded for any substances used. Advice is always given on the best control measures to help prevent ill health and employee absence.

ECL understands the risks involved in the wide variety of workplace activities associated with welding. Our experience allows us to undertake all examination of control measures and exposure prevention. Then recommend any improvements or ensure continued efficient performance. We will provide a detailed report on work practices and findings together with recommendations for remedial action.

Call us on 01443 841 760 or fill out our ECL Enquiry Form for any queries regarding workplace exposure monitoring, COSHH control measures, COSHH risk assessments, welding fume regulations or any of our many other accredited services.