Welding fumes

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

 

From 18 January 2024 the workplace exposure standard (WES) for welding fumes (not otherwise classified) has been reduced from an 8-hour time weighted average of 5 mg/m3 to 1 mg/m3.

Welding fumes explained

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 helmets 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

Exposure to welding fumes can pose both short-term and long-term health risks to workers. In the short term, inhaling welding fumes can lead to headaches, dizziness, nausea, and metal fume fever (a flu-like illness). Repeat exposure can increase the risk of serious conditions like lung cancer, kidney damage, and nerve problems.

Who is at risk

Workers who perform welding tasks and those nearby are at risk of exposure to welding fumes.

Health effects

Health effects of exposure to welding fumes and gases include:

  • 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.
This video provides practical information on how to reduce workers exposure to the risks of hazardous welding fumes and UV radiation.

Exposure standards and 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 metals and gases, the respective exposure standard for that particular chemical must not be exceeded. Refer to the Workplace exposure standards for airborne contaminants which are listed on the Safe Work Australia website and its Hazardous Chemical Information System (HCIS).

Classification

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) to help workers understand the importance of safety measures while welding.

Controlling exposure

Hierarchy of control

To protect against the risks of welding fumes, it's essential to follow the welding hierarchy of control.

Eliminate exposure

Eliminate, as far as is reasonably practicable, any exposure to welding fumes. If it's not possible to completely eliminate the risk, measures to minimise the risk should be used.

Substitution

You can do this by:

  • replacing a hazardous chemical with a less dangerous alternative. Consider the form of welding process such waveform controls (for example pulsed welding, controlled dip/short arc welding) when used on gas metal arc welding (GMAW or MIG) welding processes
  • removing surface coatings and contaminants before welding to reduce fumes

Isolation

Conduct welding in isolation booths away from others.

Engineering controls

You can do this by installing local exhaust ventilation systems to capture or remove airborne contaminants.

The four main types of ventilation are:

  • on gun fume extraction – captures the fume directly at the point of generation, requiring less repositioning
  • local exhaust ventilation (LEV) – protects workers by capturing fumes directly at the source using capture hoods. LEVs are most effective when positioned close to the welding arc
  • forced dilution ventilation – uses fans to push fresh air into the work area, diluting the concentration of welding fumes. Useful for large workshops and factories
  • natural dilution ventilation – relies on natural airflow through open doors and windows to disperse fumes. Best for outdoor or well-ventilated indoor workspaces.

Develop administrative controls

You can do this by:

  • implementing procedures to handle hazardous chemicals safely
  • educating and training 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) of welding rods to identify the gases and fumes released during welding.

Personal protective equipment

  • Welding helmets with powered air purifying respirators (PAPRs). PAPRs protect workers by:
    • filtering out dangerous welding fumes, providing respiratory protection
    • providing a continuous supply of filtered air into a welding helmet, reducing breathing resistance and offering a cooling airflow for comfort.
  • Tight fitting respirators and masks. Half-face respirators can provide additional protection when ventilation isn't enough. Workers must be clean shaven and fit-tested.
  • Protective clothing such as long-sleeved shirts and pants, gloves, and safety shoes help prevent skin contact with harmful fumes and UV radiation.

Personal protective Equipment (PPE) and Respiratory Protective Equipment (RPE) should not be relied upon as the sole protection against the risks associated with welding. PPE and RPE should 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.

By following this hierarchy, workplaces can significantly minimise the health risks associated with welding fumes, ensuring a safer environment for all workers.

Recent studies have shown that the most effective way to control exposure to welding fumes is through a combination of proper ventilation and the use of welding helmets with powered air purifying respirators (PAPRs).

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 helps determine if exposure standards are being exceeded or approached. It should be carried out when there is uncertainty about the level of the worker’s exposure. Air monitoring also tests the effectiveness of control measures in reducing exposure.

Who should conduct air monitoring

Air monitoring should be conducted by a competent person, such as an occupational hygienist. The monitoring must be done in the person'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 to worker’s health because of exposure to a hazardous chemical referred to in Schedule 14 such as lead, cadmium or chromium.

This may be the case where there is reliance on low order controls such as respiratory protective equipment or administrative controls to control excessive exposure below relevant exposure standards.

The relevant chemicals present in welding fumes that are listed in Schedule 14 are inorganic compounds of cadmium, chromium and lead. PCBUs need to determine whether these hazardous chemicals are present in the welding fumes and whether they are likely to be present in sufficient concentrations to present a significant risk to workers,

PCBUs should consult or obtain advice from a medical practitioner or occupational physician on suitable health monitoring for exposure to welding fumes.

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

Further information and resources

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