Prepare for the WES to WEL transition: Changes for welding fumes

Major changes to airborne contaminant exposure limits are approaching, with the Workplace Exposure Limits (WELs) scheduled to replace the Workplace Exposure Standards (WES) from 1 December 2026. The change is more than a change of name. Most national WELs will apply from that date, although jurisdiction-specific transitional arrangements may apply.

Some substance limits have decreased, others have increased and many remain unchanged. The new list also includes an ototoxicity notation and identifies non-threshold genotoxic carcinogens (NTGCs), for which no safe exposure threshold can be established. These changes will have a greater impact on some workplaces than others.

This article will focus on the main changes that workplaces conducting welding should be aware of.

Get in touch with your local Air-Met Scientific office today to discuss how we can help you prepare for these changes.

Welding Fume Basics and Regulation

‘Welding fumes’ is a general term for the airborne particles generated during welding. Welding can also produce hazardous gases. Fume particles are typically formed when vaporised metal cools and condenses, and their composition depends on the welding process, materials and consumables used.

Health Impacts of Exposure to Welding Fumes

Inhaling welding fumes can cause short-term health effects, including respiratory irritation, headaches, dizziness, nausea and metal fume fever, which causes fever, chills and body aches. Long-term exposure can contribute to respiratory disease, neurological effects and lung cancer.

Welding Fume Exposure in Australian Industries

It’s not just welders who may be exposed to welding fumes. Workers nearby may also be exposed, particularly in enclosed or poorly ventilated workplaces such as factories and manufacturing plants. Welding is common in Australian construction, manufacturing, defence and maritime industries.

The chemical composition of welding fumes is dependent on the specific welding process and the metals being welded. Factors affecting the composition of welding fumes include the types of metal or alloys being welded and the welding rods, electrodes and fluxes used. The risk is also different depending on the environment such as whether it is conducted indoors or outdoors.

Regulation and Changes to Welding Fume Exposure Limits Under the WEL

The complex composition of welding fumes makes exposure assessment challenging. Separate WELs apply to individual metals and gases, in addition to the general limit for welding fumes not otherwise classified (NOC). Several relevant national limits will change from 1 December 2026. Businesses must check which limits apply in their jurisdiction: in Victoria, transitional limits apply to specified substances, including manganese, certain nickel forms and nitric oxide, until 30 November 2029.

Welding-fume risks must be eliminated so far as is reasonably practicable. Where elimination is not reasonably practicable, risks must be minimised using higher-order controls such as substitution, process enclosure and local exhaust ventilation before relying on respiratory protective equipment (RPE). Meeting an exposure limit does not, on its own, establish that all reasonably practicable risk controls are in place.

Exposure Limits for Typical Welding Fumes and Gases

Metal fumes produced by welding can pose dangers to health. These substances are referred to in the Model Code of Practice: Welding processes and several have had limits or categorisation changed in the transition from WES to WEL.

It is not sufficient to assess only the general limit for welding fumes not otherwise classified. Individual constituents, including beryllium, cadmium, chromium compounds, lead, manganese and nickel, may have more restrictive limits or different assessment requirements. Welding also generates gases such as ozone and nitrogen oxides, which are not covered by the general particulate welding-fume limit. Hexavalent chromium compounds are listed as NTGCs under the national WEL framework, requiring stringent risk controls even though no numerical WEL is assigned to those entries.

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These are national reference values, not a substitute for the current legally applicable jurisdictional schedule. Victoria retains transitional limits for specified manganese and nickel entries until 30 November 2029. Confirm chemical form, sampling fraction and applicable jurisdiction before using a value for compliance decisions. Chromium(VI) compounds require separate NTGC consideration.

Several gases may be generated as by-products of welding, depending on the process and surrounding contaminants. The values below are expressed in parts per million (ppm), rather than mg/m³. Gas-specific sampling or direct-reading methods are required; particulate sampling alone cannot assess these gases.

Victoria retains a transitional limit for nitric oxide until 30 November 2029.

Sampling, Respiratory Protection and Fit Testing for Welding Fumes

As with other airborne contaminants, an effective approach combines risk assessment, appropriate engineering controls, exposure monitoring and, where required, correctly selected respiratory protective equipment (RPE). Monitoring and PPE do not replace the duty to eliminate or minimise exposure risks so far as is reasonably practicable.

Air Sampling for Compliance

A key step in assessing exposure is representative personal air sampling. Sampling can establish airborne contaminant concentrations in a worker’s breathing zone and support calculation of an eight-hour time-weighted average (TWA). Gravimetric sampling measures collected particulate mass; identifying and quantifying particular metals generally requires suitable laboratory analysis. Results can also help evaluate the performance of engineering controls, but a conventional air sample does not, by itself, demonstrate the protection achieved by a respirator.

A sampling pump such as the SKC AirChek Essential+ can draw air through a suitable collection medium positioned in the worker’s breathing zone. The pump, flow rate, sampler and analytical method must be selected for the target contaminant and the applicable sampling standard.

It is essential to choose the correct sampling medium and particle-size fraction for the substance being assessed. For example, the SKC IOM Sampler can be used for suitable inhalable particulate methods; a different sampler may be needed for respirable particulate exposure, and welding gases require separate methods. Expert occupational hygiene guidance may be necessary when multiple metal constituents are present.

Real-Time Aerosol Monitoring

To complement personal air sampling, real-time aerosol monitoring can be undertaken using an instrument such as the DustCanary Trend 420 real-time respirable dust monitor. Real-time readings can help identify concentration changes during particular tasks and illustrate the effect of ventilation or work practices. However, direct-reading aerosol instruments cannot identify individual metal constituents, and responses can be affected by particle size and composition. They therefore complement, rather than replace, substance-specific exposure sampling and laboratory analysis.

Respiratory Protective Equipment and Fit Testing

Personal protective equipment (PPE) is a lower-order control in the hierarchy of controls. Engineering measures and safe work practices should be considered first, with RPE providing an important additional layer of protection where residual welding-fume exposure remains.

Welding helmets fitted with powered air-purifying respirators (PAPR) are one RPE option for welders. These systems use a powered blower and suitable filters to supply filtered air to a compatible PAPR helmet. Protection depends on the equipment configuration, correct selection, use and maintenance.

PAPR systems may use tight-fitting or loose-fitting headtops. Tight-fitting respiratory facepieces require fit testing to confirm an adequate seal and users must be clean-shaven where the facepiece seals against the skin. Quantitative fit testing instrumentation such as the OHD Aerofit and Quantifit II should be used to test individuals in their RPE. Loose-fitting headtops generally do not require fit testing, but must still be correctly selected and used. Protection factors vary by equipment classification and configuration; loose-fitting PAPR should not automatically be described as providing a lower level of protection.

Businesses should be aware of the following standards relevant to the selection, use and fit testing of RPE:

• AS/NZS 1715:2009 ‘Selection, Use & Maintenance of Respiratory Protective Equipment (RPE)’
• AS/NZS 1716:2012 ‘Respiratory Protective Devices’
• AS/NZS ISO 16975.3:2023 ‘Fit Testing for Respiratory Protective Devices’

Ultimately, the appropriate RPE depends on the substances and concentrations involved, the controls already in place, the work being undertaken and the suitability of the equipment for the wearer. Fit testing, where required, is one part of a broader respiratory protection program.