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Welding processes expose workers (welders, flame cutters and burners) to many hazards including the inhalation of toxic welding fumes and gases.  Exposure to welding fumes can occur through inhalation, dermal and eye contact.  Welding fumes are the fumes that result from various welding operations.   Welding fumes typically have a metallic odour.  Their specific composition varies considerably depending on the type of welding and the material being welded; the primary components involved are oxides of the metals such as zinc, iron, chromium(VI), aluminium, copper or nickel.


Biological monitoring can assess exposure by all routes inhalation, ingestion and skin absorption.  A simple urine sample can provide information about an individual worker's exposure to the metals commonly found in welding fumes.  In the case of welding, biological monitoring can specifically help to assess efficacy of the respiratory and personal protection equipment (RPE/PPE) being used.  An elevated urine result would suggest the worker has some welding fume exposure and that maybe the RPE/PPE/engineering controls need to be improved.  Biological monitoring is suitable for regular monitoring to check that systems are working correctly and for investigating the extent of exposure following incidents.

Biological monitoring for welders should include the measurement of nickel and chromium in a urine sample and this should be undertaken on an annual basis where there is shown to be good control. Samples should be collected at the end of a typical working week. It may also be necessary to also monitor for other metals depending on the type of metal being welded, for example cadmium or lead should be measured if the stainless steel has been cadmium plated or if lead paint (lead oxide primer) is present.  To determine recent exposure to both cadmium and lead a blood sample is required.  Some of the metals being welded may also create a hazard, for example if welding copper beryllium alloy it would be advisable to undertake biological monitoring (with a urine sample) for beryllium.  See the table below for other metals that can be involved in each welding process.

If workers experience symptoms consistent with metal fume fever or feel unwell outside of the normal biological monitoring regime, a urine sample should be taken as soon as possible to allow any exposure to be confirmed.

Types of welding, principal metals involved and advised biological monitoring (bold - testing receommended, italics - testing to be considered, if a constituent).

Type of Welding

Material welded

Metals  involved in weld type

Flux cored arc

Mild steel and low alloy steels

Stainless Steel

Nickel alloys

Chromium, Nickel, Aluminium, Copper, Iron, Barium, Vanadium, Titanium

Manual Metal arc (flux shielded manual metal arc) (SMAW/MMA or MMAW)

Mild steel and low alloy steels

Stainless Steel,

Al,Cu, Ni Alloys, cast iron and hardfacing

Chromium, Nickel, Aluminium, Copper, Iron, Manganese, Vanadium, Titanium, Molybdenum, Antimony.

Metal inert gas (MIG, gas metal arc, GMAW)

Mild steel and low alloy steels

Stainless Steel

Aluminium alloys

Chromium, Nickel, Aluminium, Silicon, Copper, Manganese, Iron, Beryllium, Arsenic, Vanadium, Titanium, Antimony.

Tungsten Inert gas (TIG, gas tungsten arc welding)

Mild steel and low alloy steels

Stainless Steel

Chromium, Nickel, Aluminium, Magnesium, Copper, Iron, TungstenVanadium, Titanium.

Gas Welding

Mild Steel

Lead flashing

Chromium, Nickel, Aluminium, Copper, Iron, Cobalt, Lead.

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