Welding fumes

Welding processes can generate fumes made up of tiny solid particles and gases. Inhaling these fumes and gases can pose long and short-term health risks to workers.

 

The workplace exposure standard (WES) for welding fumes (not otherwise classified) and aluminium welding fumes has been reduced from an 8-hour time-weighted average of 5 mg/m³ to 1 mg/m³ to better protect workers from the harmful effects of welding fumes.

What are welding fumes

Welding fumes form when metal heats above its boiling point. As these fumes cool down, they condense into tiny particles, small enough to be inhaled into the lungs.

Some welding fumes are visible, appearing like smoke or a mist, but many fumes are invisible and can only be detected using special equipment. It’s crucial to use effective ventilation systems and personal protective equipment (PPE) like respirators and welding face shields to minimise exposure to these harmful fumes and UV radiation.

Welding fume composition

The composition of welding fumes depends on several factors, including:

  • welding process – different welding methods, like MIG, TIG, or stick welding produce varying types and amounts of fumes
  • type of base metal – the kind of metal being welded, such as steel, stainless steel, or aluminium
  • welding rod/electrode or filler metal wire, including the materials in the welding rod or wire
  • shielding gases or flux – gases like argon or carbon dioxide, or fluxes used to protect the weld
  • contaminants or coatings – rust, oil, paint, or other coatings on the metal can lead to more hazardous fumes.

Types of welding processes

There are many types of welding processes, but the most common is arc welding. Arc welding involves joining two metal parts by melting them at extremely high temperatures and allowing them to cool and fuse together.

The four main arc welding processes are:

  • flux-cored arc welding (FCAW):
    • uses a special wire filled with flux that creates a protective gas shield during welding
    • often used for heavy-duty welding tasks like shipbuilding and construction
  • manual metal arc welding (MMAW)/stick welding:
    • uses a coated metal rod (electrode) that creates an electric arc to melt the metal
    • is popular for its versatility and suitability for outdoor welding
  • gas metal arc welding (GMAW)/MIG welding:
    • uses a continuous wire feed and shielding gas to protect the weld
    • is ideal for welding thin sheets of metal and commonly used in automotive and manufacturing
  • gas tungsten arc welding (GTAW)/TIG welding:
    • uses a non-consumable tungsten electrode and a separate filler rod
    • provides precise, high-quality welds, often used for pressure piping, stainless steel and aluminium.

Risks and health hazards of welding fumes

Workers who perform welding tasks and those nearby are at risk of exposure to welding fumes. Exposure to welding fumes can pose both short-term and long-term health risks to workers.

Health effects

Health effects of exposure to welding fumes and gases include:

  • headaches, dizziness, nausea
  • irritation of the nose, throat, and lungs, leading to coughing and tightness in the chest
  • asphyxiation – difficulty breathing due to a lack of oxygen in the air, which can happen in confined spaces
  • asthma and wheezing – breathing problems that can become chronic
  • metal fume fever – a flu-like illness that can cause fever, chills, and body aches
  • lung damage – permanent damage leading to conditions like bronchitis, pneumonia, emphysema, or other chronic obstructive pulmonary disease (COPD)
  • cancer – long-term exposure can increase the risk of lung and kidney cancers
  • nerve problems.
 
This video provides practical information on how to reduce workers exposure to the risks of hazardous welding fumes and UV radiation.

Exposure standards and IARC classifications

Exposure standard

The workplace exposure standard (WES) for welding fumes (not otherwise classified) has been reduced from an 8-hour time-weighted average (TWA) of 5 mg/m³ to 1 mg/m³. This change aims to better protect workers from the health risks associated with welding fumes.

Due to welding processes generating a variety of metal fumes and gases, the respective exposure standard for that particular chemical must also not be exceeded. Refer to the Workplace exposure standards page for more information.

IARC classifications

Welding fumes and the UV radiation emitted during welding are classified as Group 1 carcinogens, meaning they are known to cause cancer in humans. This classification comes from the International Agency for Research on Cancer (IARC) emphasising the importance of eliminating and minimising exposure to welding fumes.

Controlling exposure to welding fumes

Follow the hierarchy of controls

To protect against the risks of welding fumes, it's essential to follow the hierarchy of controls. It will often be necessary to use more than one control measure where the risk cannot be eliminated.

Eliminate exposure

Remove the need to weld, so far as is reasonably practicable. For example, some fabrications may be designed to include many pre-cast components or extruded shapes to eliminate the need to weld.

Substitution

Where elimination is not reasonably practicable, reduce welding fumes at the source by using processes, consumables, gases and other inputs that generate less fume.

Use alternative processes or settings that lower fume:

  • Apply waveform or arc-control technologies (for example, pulsed GMAW, controlled dip/short-arc) to stabilise the arc and reduce spatter and fume.
  • Where practicable, choose lower-fume processes suited to the job (for example, GTAW/TIG for appropriate applications).

Use alternative consumables that produce lower fume:

  • Choose low-fume or low-manganese solid wires and flux-cored wires where appropriate.
  • Use filler rods or electrodes designed to reduce fume generation and avoid electrodes with hazardous flux coatings (such as those containing high levels of manganese or other toxic metals).
  • Follow manufacturer-recommended parameters (voltage, amperage, wire-feed speed), as running hotter than necessary increases fume.

Use shielding gases that minimise fume generation:

  • Use argon‑rich shielding gas blends, where compatible with the welding procedure, as they generally produce less fume than pure CO₂.
  • Use gas mixtures optimised for stable arcs and reduced fume output.

Remove coatings and contaminants before welding:

  • Clean or strip paint, primers, oils, galvanising, rust and other surface contaminants to prevent additional hazardous fume generation.
  • Use suitable surface preparation methods (mechanical or chemical) and dispose of residues safely.

Isolation

Minimise the risk by isolating or separating welding activities from other workers. This involves physically separating the welding fume source from anyone who could be exposed.

Examples of isolation include:

  • conducting welding in isolation booths or designated welding bays to prevent fume from spreading
  • using screens, barriers or enclosures to separate welding tasks from nearby workers
  • locating high-fume or ancillary hot-work processes (for example, gouging, plasma cutting) in separate areas away from general workspaces.

Engineering controls

Install engineering controls to capture or remove airborne contaminants at the source.

Ventilation is one of the most common engineering controls used to manage welding fumes. The four main types of ventilation are:

  • on gun fume extraction, which captures the fume directly at the point of generation, requiring less repositioning
  • local exhaust ventilation (LEV), which captures fumes directly at the arc using movable extraction hoods or down draft ventilation tables. LEV is most effective when positioned close to the welding arc
  • forced dilution ventilation, which uses roof or wall fans to introduce fresh air into the work area, helping to dilute airborne contaminants. This type of ventilation can support other controls in large workshops and factories, but it should not be relied on as a primary control for welding fumes
  • natural dilution ventilation, which relies on constant natural airflow through open doors and windows to disperse fumes. This may assist overall air movement in larger, well-ventilated indoor areas or outdoor workspaces, but it is not sufficient as a primary control for welding fumes.

Administrative controls

Reduce exposure by:

  • implementing safe procedures for handling hazardous chemicals
  • training and consulting with workers about welding risks and safe work practices
  • reducing the quantity of hazardous chemicals used or stored in the workplace
  • checking the safety data sheets (SDS) for consumables to identify fume and gas hazards.

Personal protective equipment (PPE)

Where PPE is provided to minimise risks to workers, it must be suitable for the nature of the work and any associated hazards. This includes being the correct size, properly fitted and is reasonably comfortable for the worker.

PPE is necessary to protect against radiation (UV/IR), burns, electric shock, and noise hazards that are generated by welding and allied processes.

Respiratory protective equipment (RPE)

RPE is likely to be necessary to protect from welding fumes and gas hazards. The appropriate type of RPE depends on the welding process, exposure levels, and the effectiveness of other controls. Appropriate selection, fit‑testing and maintenance are essential to ensure protection.

Tight-fitting air purifying respirators (full-face or half-face):
  • provide respiratory protection when correctly selected, fit-tested, maintained and worn.
  • require workers to be clean shaven where the respirator seals against the face.

Particulate filters (P2 or P3) do not protect against gases such as ozone or nitrogen oxides. Correctly selected combined particulate and gas/vapour filters provide protection for some gases and vapours.

Powered air purifying respirators (PAPR)

Powered air purifying respirators (PAPR) worn with a welding helmet have the advantage of not requiring a tight face seal and may be appropriate for workers with facial hair.

In addition, PAPRs can provide a higher level of protection and comfort for the user.

Important considerations

Supplied air respirators may be necessary for work in confined spaces or situations involving high fume concentrations, and specialist advice should be obtained.

Personal protective Equipment (PPE) and Respiratory Protective Equipment (RPE) should not be relied upon as the sole protection against the risks associated with welding. They must be used as part of a comprehensive safety plan that includes engineering controls like local exhaust ventilation (LEV) and safe work practices.

A combination of controls can significantly reduce exposure to hazardous fumes and ensure a safer working environment for everyone involved.

Air monitoring

Air monitoring is the process of sampling the workplace atmosphere to estimate workers' potential exposure to hazardous chemicals through inhalation.

When to conduct air monitoring

Air monitoring should be carried out when there is uncertainty about a worker’s level of exposure and whether the exposure could exceed the workplace exposure standard (WES). It can also be used to assess the effectiveness of existing control measures in minimising exposure.

Who should conduct air monitoring

Air monitoring should be conducted by a competent person, such as an occupational hygienist, with samples taken in the worker's breathing zone to accurately determine their exposure to airborne contaminants.

Health monitoring

Persons conducting a business or undertaking (PCBUs) must ensure that health monitoring is carried out for a worker if there is a significant risk their health from exposure to any Schedule 14 hazardous chemicals, such as lead, cadmium or chromium.

This requirement may apply where a PCBU is relying on lower-order controls, such as respiratory protective equipment or administrative controls, to keep exposure below the relevant workplace exposure standards.

Welding fumes can contain Schedule 14 metals, and PCBUs must determine whether welding tasks may generate these substances at levels that could pose a significant risk to workers.

PCBUs should also consult, or obtain advice from, a medical practitioner or occupational physician experienced in health monitoring to determine the appropriate monitoring for workers exposed to welding fumes.

Guidance on suitable health monitoring for specific hazardous chemicals is available from SafeWork Australia.

Further information and resources

A thumbnail showing the first page of the welding processes code of practice.
Code of Practice: Welding processes

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