Substances

Welding fume

Also called welding smoke, mild steel welding fume, stainless steel welding fume.

A mixture of metal oxides and gases given off during welding. Since 2019 HSE treats all welding fume, including mild steel, as a cause of lung cancer. Individual components such as manganese, chromium VI and nickel have their own exposure limits.

Last reviewed 8 September 2026

Hazard data from HSE EH40 and HSE guidance, checked 8 September 2026. Confirm the concentration and form against the supplier data sheet for the product you use.

Identification

Physical formfume
Signal wordNone
PictogramsNone
Routes of exposureinhalation

Hazard classification

    Hazard statements

      Workplace exposure limit

      No workplace exposure limit is listed in EH40/2005. Exposure must still be reduced as low as is reasonably practicable and adequately controlled.

      COSHH status

      HSE safety alert, February 2019: all welding fume is carcinogenic. Local exhaust ventilation is expected indoors and RPE where LEV alone does not control exposure, including outdoors. There is no single WEL for the fume; component limits from EH40 apply: manganese 0.2 mg/m³ inhalable and 0.05 mg/m³ respirable, chromium VI 0.01 mg/m³ (0.025 mg/m³ where process generated), nickel 0.1 mg/m³ soluble and 0.5 mg/m³ insoluble, iron oxide fume 5 mg/m³ with a 10 mg/m³ short term limit.

      Common uses

      • MIG, TIG, MMA and oxy-fuel welding
      • Flame cutting
      • Grinding after welding

      First aid

      Inhaled: fresh air. Flu like symptoms after welding galvanised steel (metal fume fever) need medical advice.

      In an emergency call 999. For advice call NHS 111. Always follow section 4 of the safety data sheet for the product you have.

      Storage

      Not applicable.

      Sources

      We do not host or copy manufacturer safety data sheets. Ask your supplier for the current sheet for the product you use.