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Important Legal Change - HSE Identify Welding as Carcinogenic

Health & Safety

Mild Steel Welding Fume

HSE has with immediate effect increased its enforcement expectation for all welding fume, including mild steel.


HSE state the reason for this change is due to ‘new scientific evidence from the International Agency for Research on Cancer shows that exposure to mild steel welding fume can cause lung cancer and possibly kidney cancer in humans’.

Therefore The Workplace Health Expert Committee has endorsed the reclassification of mild steel welding fume as a human carcinogen.

Actions required

Suitable actions should take the form of engineering controls for all welding activities indoors e.g. Local Exhaust Ventilation (LEV). It is deemed that general ventilation (normal air movement) does not achieve the necessary control.

Additionally, it should be noted that mechanical extraction also controls potential exposure to manganese. This substance is also present in mild steel welding fume and has been linked to neurological effects similar to that of Parkinson’s disease.

If the mechanical controls (LEV) do not capture all the fumes then suitable respiratory protective equipment (RPE) should be provided to protect against the residual fume. RPE should also be provided to those welders working outside.

Your risk assessments for welding now need to be revised to incorporate these changes.

Your risk assessments for welding now need to be revised to incorporate these changes.

There is no known level of safe exposure.


You need to ensure all of your engineering controls are used properly, covered by a scheme of regular maintenance and subject to thorough examination and test where required.

Those employees that use RPE should be included in an RPE programme, which covers for example: correct usage, maintenance and storage.

Further information

Welding Fume, produced by all welding processes. Combination of hot gases mixed with tiny solid metal particles.

Hot gas/fumes includes oxides of nitrogen (NOx) (damage to lung tissue) and carbon monoxide (CO) (toxic on inhalation) and ozone (damage to lung tissue).

Particles in fumes circa 1 micron (human hair is 50-100 microns), are not to be visible to the eye under normal lighting conditions.

Types of Welding

Arc Welding

An electric arc between an electrode and the work metal creates the very high temperatures required to melt the metal.

Oxyfuel Gas Welding

A gas torch (oxyacetylene) is used to provide high temperatures.

Metal Inert Gas (MIG) 
A consumable wire electrode is melted by the electric arc within a shielding gas (such as argon) to prevent atmospheric oxygen combining with the metal which would then from a poor weld finish (slag).

If this change impacts on your business, please contact your LAW Health & Safety Manager to discuss your requirements as a matter of urgency.

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