Australia is approaching an important change in the way workplace exposure to airborne contaminants is regulated.
From 1 December 2026, the existing Workplace Exposure Standards (WES) for airborne contaminants will transition to Workplace Exposure Limits (WEL). The change follows a national review of workplace exposure standards and has been agreed by Australian Work Health and Safety (WHS) ministers.
For many workplaces, this is more than simply a change of terminology. While many exposure values will remain unchanged, some limits have been revised, some substances have been added or removed, and there are changes to exposure categories and health-related notations.
With the transition date now approaching, employers should be reviewing their chemical inventories, risk assessments, exposure monitoring and control measures now, not waiting until December.
What Is Changing?
The current WES list sets airborne exposure levels for hundreds of substances that workers may encounter in the workplace, including dusts, fumes, gases, vapours and mists.
From 1 December 2026, the WES list will become the Workplace Exposure Limits for Airborne Contaminants (WEL list). Until 30 November 2026, PCBUs must continue to comply with the current WES requirements. From 1 December, the WEL list will apply, subject to implementation in the relevant Commonwealth, state or territory WHS laws.
The terminology is changing partly to make it clearer that these values are limits that must not be exceeded, rather than simply advisory standards or targets. Safe Work Australia says the change also brings Australian terminology more closely into line with international practice.
Importantly, the fundamental duty on employers has not changed.
PCBUs must continue to eliminate risks associated with airborne contaminants where reasonably practicable, or otherwise minimise those risks so far as is reasonably practicable. The WES/WEL value is only one part of a broader risk-management process.
What Does The Change Mean For Employers?
The biggest practical issue for employers is determining whether the substances used or generated in their workplace are affected by the revised WEL list.
Safe Work Australia has identified several types of changes, including:
- reductions or increases to individual exposure limits;
- changes to the type of exposure limit applying to a substance;
- merging or splitting groups of airborne contaminants;
- changes to substance names or listings;
- new substances being added to the list; and
- substances being removed from the list.
There are also changes to advisory notations. For example, the existing SEN sensitisation notation is being separated into DSEN for dermal sensitisation and RSEN for respiratory sensitisation. An OTO notation for ototoxicity has also been introduced for certain contaminants.
These changes can have practical consequences for risk assessments, control measures, air-monitoring programs, worker information and training.
Some Chemicals Require Particular Attention
One of the more significant changes concerns 33 non-threshold genotoxic carcinogens (NTGCs).
From 1 December 2026, these substances will no longer have exposure limits in the WEL list because a practical, protective exposure level cannot be assigned. Where these substances are present, PCBUs must eliminate them where reasonably practicable, substitute them with a safer alternative where possible, or otherwise minimise the risk as far as reasonably practicable.
This means businesses should not assume that the absence of a WEL means there is no regulatory obligation.
The opposite may be true: the risk-management requirements may require particularly strong attention to elimination, substitution and engineering controls.
What About Respirable Crystalline Silica and Other High-Profile Substances?
It is important to distinguish the general WEL transition from separate work that has been undertaken on proposed changes to nine substances.
These include:
- respirable crystalline silica;
- benzene;
- chlorine;
- copper;
- formaldehyde;
- hydrogen cyanide;
- hydrogen sulphide;
- nitrogen dioxide; and
- titanium dioxide.
In June 2026, Safe Work Australia reported that a majority of WHS ministers had not supported the proposed new exposure levels for those nine substances at that stage, and further work was requested. Consequently, their exposure levels will remain at their current WES levels when the WEL framework takes effect on 1 December 2026.
Businesses should therefore use the current Safe Work Australia WEL information rather than relying on older articles, consultant reports or chemical registers prepared before the review was finalised.
What Does The Change Mean For Workers?
For workers, the transition should reinforce an important principle: exposure limits are not a substitute for good risk control.
Workers should continue to follow existing safe-work procedures, use control measures correctly and report problems with ventilation, extraction, PPE or other controls.
Safe Work Australia also recommends that workers familiarise themselves with changes to the limits for airborne contaminants used or generated in their workplace. Workers should be consulted where employers are making decisions about how risks will be eliminated or minimised, or where proposed changes may affect their health and safety.
It is also worth remembering that an exposure limit is not necessarily a guarantee that every individual will experience no health effect below that concentration. Individual susceptibility varies, which is one reason Australian WHS duties continue to require risks to be eliminated or minimised so far as reasonably practicable.
What Should Employers Do Before 1 December 2026?
With the transition only weeks away, businesses should treat this as a practical WHS review rather than simply an administrative change.
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Identify every airborne contaminant in the workplace
Start with a complete inventory of substances that could become airborne.
Look beyond chemicals stored in drums or containers. Consider contaminants generated by work processes, including:
- welding fumes;
- dust;
- silica-containing dust;
- diesel particulate matter;
- solvent vapours;
- gases;
- mists;
- fumes from heating or cutting;
- dust generated during machining or processing; and
- contaminants generated by maintenance, cleaning or waste processes.
Review Safety Data Sheets (SDS), chemical registers, purchasing records and process documentation.
The objective is to identify not only what the business uses, but also what its processes generate.
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Compare your current WES against the new WEL
For each relevant airborne contaminant, check the new WEL list.
Do not simply change the heading in your documentation from “WES” to “WEL”.
Determine whether the actual exposure value, exposure category, notation or substance listing has changed.
Safe Work Australia has published comparison information specifically to help PCBUs identify changes between the WES and WEL lists.
This provides a straightforward audit trail for the transition.
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Review existing risk assessments
Once the affected substances have been identified, revisit the relevant risk assessments.
Ask:
- Has the exposure limit changed?
- Does the current assessment rely on an old WES value?
- Are workers potentially exposed during particular tasks or maintenance activities?
- Are there short-term or peak exposure risks?
- Are contractors or other people at the workplace potentially exposed?
- Have processes, equipment or chemicals changed since the assessment was completed?
- Are existing controls still appropriate?
This is particularly important where a new WEL is lower than the existing WES.
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Determine whether air monitoring is necessary
Where there is uncertainty about whether workers are exposed above the relevant limit, air monitoring may be necessary.
Safe Work Australia’s new guidance, published in July 2026, provides specific information for PCBUs on when air monitoring may be required, how to engage a competent person, and how to interpret monitoring results.
Air monitoring should not be treated as the first or only control.
The hierarchy of controls remains central. The preferred approach is to eliminate the airborne contaminant where reasonably practicable and, where that cannot be achieved, minimise the risk using appropriate controls.
Where monitoring is undertaken, consider whether personal exposure monitoring is necessary rather than relying solely on general area measurements.
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Review engineering controls
The WEL transition is a good opportunity to verify that engineering controls are actually performing as intended.
Depending on the workplace, this may include checking:
- local exhaust ventilation (LEV);
- extraction systems;
- enclosure and isolation systems;
- process ventilation;
- dust suppression;
- automated handling;
- closed transfer systems;
- equipment maintenance; and
- filtration systems.
A documented control that exists on paper but does not adequately control exposure in practice does not provide effective risk management.
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Review PPE and respiratory protection
PPE should not be used as a substitute for higher-order controls where those controls are reasonably practicable.
However, businesses should review respiratory protective equipment where it forms part of the control strategy.
Check that:
- the selected respirator is appropriate for the contaminant;
- workers are correctly trained;
- fit testing requirements are addressed where applicable;
- filters and cartridges are appropriate;
- maintenance and replacement arrangements are effective; and
- workers understand when and how the equipment must be used.
Any change in exposure level may warrant a review of the existing respiratory protection arrangements.
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Review health monitoring requirements
Some hazardous chemical exposures can trigger specific health-monitoring obligations under WHS legislation.
The WEL transition should therefore prompt a review of whether existing health-monitoring arrangements remain appropriate for the substances and exposure scenarios present at the workplace.
This is separate from air monitoring: air monitoring measures exposure in the workplace, while health monitoring assesses aspects of a worker’s health in accordance with applicable requirements.
Businesses should seek competent professional advice where the interaction between exposure, health monitoring and WHS requirements is unclear.
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Consult workers
Worker consultation should be part of the transition process, not something left until the new limits come into effect.
Workers often have practical knowledge about where exposure occurs that may not be obvious from a written risk assessment.
Discuss:
- which tasks generate dust, fumes, vapours or other contaminants;
- when exposure appears to be highest;
- whether controls are practical during real work;
- problems with extraction or ventilation;
- PPE issues;
- changes to work procedures; and
- any proposed additional monitoring or controls.
Safe Work Australia specifically highlights consultation as part of preparing for the WEL transition.
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Update WHS documentation
Once the assessment is complete, update relevant documentation, including:
- chemical registers;
- risk assessments;
- hazardous chemical procedures;
- Safe Work Method Statements (where applicable);
- operating procedures;
- air-monitoring programs;
- training materials;
- induction materials;
- emergency procedures; and
- internal WHS registers.
Make sure documents distinguish between the requirements applying before and from 1 December 2026 where necessary.
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Communicate the changes
Workers do not need to become occupational hygienists, but they should understand what the change means for their work.
For example, toolbox talks or training sessions could explain:
What is changing?
WES will become WEL from 1 December 2026.
Why is it changing?
The WES review has resulted in revised exposure limits and terminology intended to make clear that these are limits that must not be exceeded.
What does it mean for our workplace?
Some of the substances we use or generate may have different limits or classifications.
What do workers need to do?
Continue following established controls, report problems and participate in any monitoring, training or consultation.
A Special Consideration: Diesel Engine Emissions
Businesses that operate diesel-powered equipment should pay particular attention to the transition.
Safe Work Australia has identified a new workplace exposure limit for diesel particulate matter of 0.01 mg/m³, which will apply from 1 December 2026. New guidance has also been released covering industries including mining, quarrying, tunnelling, construction, agriculture, transport and logistics, oil and gas, and vehicle maintenance.
For workplaces with diesel engines, this should trigger a review of sources, ventilation, work practices, maintenance and exposure monitoring.
A Practical WEL Transition Checklist
Before 1 December 2026, employers should consider completing the following:
- Identify all airborne contaminants used or generated at the workplace.
- Review relevant Safety Data Sheets and chemical registers.
- Compare current WES values against the new WEL list.
- Identify substances with changed exposure limits.
- Identify new or removed substances and changed notations.
- Check whether any NTGCs are present.
- Review existing risk assessments.
- Determine whether air monitoring is required.
- Engage a competent occupational hygienist where specialist assessment is needed.
- Review engineering and ventilation controls.
- Review respiratory protection and PPE arrangements.
- Review health-monitoring requirements.
- Consult workers and health and safety representatives.
- Update procedures, risk assessments and registers.
- Update worker training and induction material.
- Document actions and assign responsibility for outstanding controls.
- Confirm requirements with the relevant state, territory or Commonwealth WHS regulator.
Don’t Wait Until 1 December
The WES-to-WEL transition is sometimes described as a change in terminology. That description misses the practical implications.
The name is changing, but the more important issue for employers is that some exposure limits and classifications are changing as well.
The good news is that businesses do not need to reinvent their entire hazardous-chemical management system. Existing risk-management processes provide the foundation. The immediate task is to identify where the new WEL requirements differ from the requirements currently being applied and determine whether existing controls remain effective.
For Australian workplaces, the key date is 1 December 2026. Until 30 November, the current WES list continues to apply; from 1 December, the WEL list will apply following implementation in the relevant WHS laws.
Businesses should therefore use the remaining transition period to complete the review, undertake any necessary monitoring, strengthen controls and communicate the changes to workers.
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The Safe Work Australia WEL list and supporting guidance should be treated as the primary reference point, with businesses also checking the requirements of their relevant WHS regulator because Commonwealth, state and territory regulators are responsible for administering and enforcing WHS laws in their respective jurisdictions.
Further Resources
Employers can access the current Safe Work Australia Workplace Exposure Limits list, the comparison of changes between WES and WEL, and the Safe Work Australia guidance on air monitoring and WELs.
For Queensland businesses, WorkSafe Queensland’s information on the new Workplace Exposure Limits is also relevant.
This article provides general information and is not legal or occupational hygiene advice. Australian WHS requirements can differ between jurisdictions, so businesses should confirm the applicable requirements with their relevant WHS regulator and obtain competent professional advice where necessary.
