Welding

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.  In February 2020 new guidance about LEV and RPE for mild steel welding was issued by HSE and there are workplace actions required to comply with the guidance.

An elevated urine result would suggest the worker has some welding fume exposure and that 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 - online ordering is available. It may also be possible to monitor for other metals depending on the type of metal being welded, for example manganese and copper for mild steel, aluminium for alloyed steels, beryllium in copper beryllium alloy. 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.  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.

For further information about all types of welding information and safety, please visit: https://www.hse.gov.uk/welding/

Types of welding, principal metals involved and advised biological monitoring (bold - testing recommended, 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, Tungsten,  Vanadium, Titanium.
Gas Welding	Mild Steel Lead flashing	Chromium, Nickel, Aluminium, Copper, Iron, Cobalt, Lead.