Workplace exposure limits - Frequently asked questions

Work processes can release dusts, gases, fumes, vapours and mists into the air. They are called airborne contaminants, and exposure can be harmful to health. Many of these may not be visible to the naked eye.

Employees exposed to airborne contaminants at work may be at risk of adverse health effects ranging from immediate discomfort such as eye and throat irritation to respiratory disease and cancer.

Safe Work Australia (SWA) publishes and maintains the Workplace exposure standards for airborne contaminants list (WES list). The WES list is a list of hazardous substances that have an exposure standard.

From 1 December 2026, SWA will replace the WES list with the Workplace exposure standards for airborne contaminants list (WEL list).

A WES or WEL is the maximum airborne concentration of a substance in an employee’s breathing zone that most (but not all) employees can be exposed to without harm to their health.

Exposure limits may be expressed as an 8-hour time-weighted average (TWA), a short-term exposure limit (STEL) or a Peak limitation.

• A TWA is the average airborne concentration of a substance over an eight-hour working day and a 40-hour working week.
• A STEL applies to the average airborne concentration over a 15-minute period.
• A Peak limitation is a concentration that must not be exceeded at any time during workplace exposure.

Some substances have more than one type of exposure limit.

Exposure limits are set at levels intended to protect employees from adverse health effects resulting from workplace exposure to airborne contaminants. However, exposure limits do not identify the dividing line between a healthy and unhealthy work environment. Individual factors, such as existing medical conditions, may mean some people experience health effects at levels below the applicable exposure limit.

Employers must eliminate risks associated with exposure to harmful substances so far as is reasonably practicable. If elimination is not reasonably practicable, employers must reduce those risks so far as is reasonably practicable. Where an exposure limit applies, employers must also ensure employees are not exposed above that limit.

Work Health and Safety (WHS) ministers have agreed to replace the WES list with the WEL list from 1 December 2026.

The WEL list includes a range of changes to exposure limits and airborne contaminant listings, including:

• 31 airborne contaminants with limits introduced for the first time
• reduced or increased exposure limits for some airborne contaminants
• 33 non-threshold genotoxic carcinogens (NTGCs) that will no longer have exposure limits
• 6 other airborne contaminants removed because their import, manufacture and use are prohibited under Australian legislation
• other changes to names, groupings, exposure-limit types and advisory notations.

In Victoria, transition arrangements apply to 15 substances until 1 December 2029.

The WEL list is the result of SWA's national review of the WES framework. The review considered current scientific and health evidence and led to changes designed to better protect employees from exposure to harmful airborne contaminants.

Yes, but specific Victorian arrangements apply.

From 1 December 2026, Victoria will adopt the national WEL list with transition arrangements for 15 substances. The 15 substances include diesel particulate matter (DPM), which has specific arrangements that differ between underground mining work and all other industries.

See Fifteen substances with a transition period in Victoria and Diesel particulate matter (DPM) in Victoria.

The changes apply to employers and self-employed people at workplaces where employees are, or who may be, exposed to airborne contaminants at levels likely to exceed the exposure limit.

This includes workplaces where chemicals and substances are used, produced, handled or generated through work processes. Examples include manufacturing, construction, mining, agriculture, transport and waste management.

Employers must continue to eliminate risks from exposure to airborne contaminants so far as is reasonably practicable. If elimination is not reasonably practicable, employers must reduce those risks so far as is reasonably practicable. Employers must also ensure that any remaining exposure does not exceed the applicable exposure standard or limit.

No. The changes do not create new duties for employers under Victoria’s occupational health and safety laws.

Employers must continue to eliminate risks from exposure to airborne contaminants so far as is reasonably practicable. If elimination is not reasonably practicable, employers must reduce those risks so far as is reasonably practicable using the hierarchy of controls. Employers must also ensure that any remaining exposure does not exceed the applicable exposure standard or limit.

From 1 December 2026, the limits in the WEL list will apply to most substances and mixtures, while Victorian transition arrangements will apply to 15 substances. Employers should review their current controls and make any changes needed to manage exposure risks and comply with the applicable exposure standards or limits

To prepare for the adoption of the WEL list SWA have published a comparison of the changes between the WES list and the WEL lists, including airborne contaminants with new, revised or removed exposure limits

Visit: comparison of the changes in airborne contaminant listings between the WES and the WEL lists.

Employers must first consider whether risks from exposure to airborne contaminants are being eliminated or reduced so far as is reasonably practicable using the hierarchy of controls.

Employers must then consider whether any remaining exposure could exceed the applicable exposure standard or limit.

Whether changes are needed will depend on the substances used or generated in the workplace, the level of exposure and the effectiveness of the controls already in place. If a new or reduced WEL applies, employers should review their controls and determine whether further action is needed before the new limit takes effect.

During the SWA national review of the workplace exposure standards framework, 9 chemicals were separately assessed. These are:

• benzene
• chlorine
• copper
• formaldehyde
• hydrogen cyanide
• hydrogen sulphide
• nitrogen dioxide
• respirable crystalline silica (RCS)
• titanium dioxide

WHS Ministers considered the Decision RIS for proposed WEL for 9 chemicals. All Ministers agreed further work was required.

Victoria supports the nationally agreed decision and will continue to work with Safe Work Australia and other jurisdictions on implementation of the WEL framework.

From 1 December 2026, the WEL list will include the 9 chemicals at the same numerical limits as in the current WES list.

We will provide updates on our website as further information about these chemicals becomes available.

The changes to Victoria's regulations relating to WEL enable the outcomes of any further national work on these 9 chemicals to be adopted in Victoria without a separate regulatory process.

Please note, however, if there is a need to deviate from the national approach for the limits in the WEL list or commencement dates we will need to amend Victorian regulations, which will require a RIS or RIS exemption.

WorkSafe will provide information as further updates become available.

Victoria has provided a three-year transition period for the following 15 substances:

• bitumen fumes
• diesel particulate matter (DPM), measured as respirable elemental carbon
• flour dust
• grain dust
• hydrogen fluoride
• manganese fume, dust and compounds (respirable)\
• methyl bromide
• nickel metal, powder, nickel sulphide roasting (dust and fume)
• nitric oxide
• perchloroethylene
• phosphine
• Portland cement (respirable dust)
• styrene monomer
• sulphur dioxide
• wood dust (softwood).

Following consideration of submissions and further analysis, including advice from occupational hygienists and other subject matter experts, the Victorian Government determined that a transition period should be adopted for 15 substances where implementation challenges were identified.

The transition period provides a clear pathway for employers to progressively achieve compliance with the new WEL. This approach is intended to make compliance achievable, encourage sustained focus on exposure reduction, and provide time for businesses to plan and implement necessary changes, including investment in engineering controls.

The new WELs for the 15 substances apply in Victoria from 1 December 2029. DPM, measured as respirable elemental carbon, has industry-specific exposure limits in Victoria for underground mining work and all other industries. For further information on DPM arrangements, see Diesel particulate matter in Victoria.

Until 1 December 2029, substances listed in Schedule 8A of the Occupational Health and Safety Amendment (Workplace Exposure Limits) Regulations 2026 and Schedule 1A the Dangerous Goods (Storage and Handling) Amendment (Workplace Exposure Limits) Regulations 2026 will be subject to the exposure limits specified in that Schedule, rather than the limits in the national WEL list.

Flour dust, manganese fume, dust and compounds (as Mn) (respirable) and Portland cement (respirable dust) do not currently have an exposure limit. For these substances, the new WEL apply from 1 December 2029.

A summary of the Victorian limits that apply from 1 December 2026 and the limits that apply from 1 December 2029 is available in the Victorian Workplace exposure limits quick reference table on our website.

Existing health and safety duties continue to apply during this period.

Employers must eliminate risks from exposure to airborne containments so far as is reasonably practicable. If elimination is not reasonably practicable, employers must reduce those risks so far as is reasonably practicable using the hierarchy of controls.

Employers must also ensure that any remaining exposure does not exceed an applicable exposure standard or diesel particulate matter limit.

Employers should use the transition period to understand the new limits, review their current controls and implement any further controls needed before the new limits apply.

No. The transition period is intended to give employers time to prepare for the lower limits, not to delay action. Exposure limits are not a target. Employers should continue to eliminate risks so far as is reasonably practicable, or reduce risks using the hierarchy of controls, even where exposures are below the applicable exposure limit.

DPM is measured as respirable elemental carbon (REC).

The applicable DPM exposure limit depends on whether the work is undertaken in underground mining work or another industry and whether the exposure occurs before or on 1 December 2029.

In Victoria, the exposure limit for DPM measured as REC may differ from the WEL.

Applicable limits in Victoria:

NTGCs are substances that can damage a person's genetic material (DNA) and may cause cancer. Based on current scientific knowledge, no safe level of exposure has been identified for these substances. Because of this, any exposure may increase the risk of cancer.

A number of substances are identified as NTGCs under the national WEL framework.

NTGCs are listed in Appendix B of Safe Work Australia's Workplace exposure limits for airborne contaminants.

No. From 1 December 2026, NTGCs will not have WEL assigned under the national framework. This is because a protective exposure level cannot be established for these substances based on current scientific knowledge.

The absence of a WEL does not mean these substances are unregulated or that exposure does not need to be controlled.

Until 1 December 2026, employers must continue to ensure that exposure does not exceed the current WES, if any, applicable to the substance.

No. However, employers must eliminate risks associated with NTGCs so far as is reasonably practicable. If elimination is not reasonably practicable, employers must reduce the risks so far as is reasonably practicable using the highest level of control measures available.

This may include substituting the substance with a safer alternative where one is available.

Employers must eliminate risks associated with exposure to NTGCs so far as is reasonably practicable. If elimination is not reasonably practicable, employers must reduce those risks so far as is reasonably practicable by applying the hierarchy of controls.

Depending on what is reasonably practicable when reducing the risk, this may include:

• substituting the substance with a safer alternative
• isolating employees from exposure
• using engineering controls to minimise exposure
• using administrative controls and
• using personal protective equipment (PPE) to further reduce any remaining risk.

WorkSafe Victoria provides guidance on air monitoring (also known as atmospheric monitoring), including:

• what air monitoring is
• when air monitoring may be needed
• who is qualified to conduct air monitoring
• interpreting monitoring results
• reviewing the effectiveness of control measures
• actions to take if exposure standards may be exceeded.

Visit WorkSafe’s Exposure standards and atmospheric monitoring webpage for more information.

A change to a WEL does not automatically mean air monitoring is required. However, employers need to assess what current exposure levels are and whether additional controls will be required to meet the new WEL.

To identify substances in your workplace, review your hazardous chemical register, safety data sheets (SDS), air monitoring results and workplace processes. Some airborne contaminants can also be generated by work activities, such as welding, decanting, cutting, grinding, quarrying, crushing, or operating diesel-powered equipment.

You can check the WEL list to see whether substances used or generated in your workplace are affected by the changes. The list includes substances with revised limits and those subject to transition arrangements in Victoria.

The Safe Work Australia airborne contaminants information hub can help you understand more about airborne contaminants, how to manage them, and changes to workplace exposure standards.

Businesses should identify any airborne contaminants that may be present in the workplace and ensure risks for exposure are eliminated or reduced so far as reasonably practicable using the hierarchy of controls.

They should then consider whether any remaining exposure could exceed the applicable exposure standard or limit and whether additional controls are needed. Businesses should seek expert advice where necessary.

You can find information about the national WES and the WEL at the Safe Work Australia airborne contaminants hub. 

To view the lists and the changes between them, visit:

• Workplace exposure limits for airborne contaminants
• Workplace exposure standards for airborne contaminants
• Changes between the WES and WEL  

For information about the exposure limits and commencement dates that apply in Victoria visit:

• Workplace exposure standards/limits

For information about the Victorian arrangements prescribed in the amendment regulations, refer to:

• the Occupational Health and Safety Amendment (Workplace Exposure Limit) Regulations 2026
• the Dangerous Goods (Storage and Handling) Amendment (Workplace Exposure Limit) Regulations 2026

Employers must eliminate risks from airborne contaminants so far as is reasonably practicable or, if elimination is not reasonably practicable, reduce those risks so far as is reasonably practicable using the hierarchy of controls.

If atmospheric monitoring shows that an applicable exposure standard or limit has been exceeded, the employer must review the controls in place and take action to reduce exposure using the hierarchy of control.

You can seek advice from a qualified and experienced occupational health and safety professional, such as an occupational hygienist, who can help assess exposure risks and recommend appropriate control measures.

Visit

• WorkSafe’s Workplace exposure standards and limits web page.
• Safe Work Australia’s airborne contaminants hub.

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