Workplace Exposure Limits – airborne contaminants

Australia is transitioning to the Workplace exposure limits for airborne contaminants (WEL list). Until 1 December 2026, you must still comply with the Workplace exposure standards for airborne contaminants (WES list). Contact your work health and safety regulator for further information. 

What is the WEL?

An airborne contaminant is a fume, mist, gas, vapour or dust that can be harmful to health when breathed in. They may not be visible to the naked eye nor detected by odour. They may arise from chemicals or materials used in the workplace or be generated by work processes.

The risks from airborne contaminants in the workplace must be managed by PCBUs by eliminating the airborne contaminants if it is reasonably practicable to do so. If it isn’t reasonably practicable to eliminate, PCBUs must minimise the airborne contaminant so far as is reasonably practicable.

PCBUs must also ensure that no person at the workplace is exposed to a substance or mixture in an airborne concentration that exceeds the exposure limit for that substance or mixture. Air monitoring must be carried out to determine the airborne concentration of the substance or mixture.

The hierarchy of control measures should be used to control risks and reduce exposure to airborne contaminants. Protection provided by respiratory protective equipment (RPE) can be taken into account when determining compliance with the WEL once all reasonably practicable higher order controls have been implemented, and the RPE is worn correctly.

The WEL is not the dividing line between a healthy and unhealthy work environment. Natural human biological variations and individual susceptibilities (such as a pre-existing medical condition) mean a small number of people may still experience adverse health effects from exposure to levels below the WEL. As such, you must always eliminate the risk of exposure to airborne contaminants so far as is reasonably practicable. If it is not reasonably practicable to eliminate the risk, minimise the risk so far as is reasonably practicable. 

Why are we transitioning to the WEL?

The WEL is a result of the review of the WES. The review of the WES was conducted to ensure that the WES are based on contemporary health evidence and provide the best protection for workers. This is the first time the WES were reviewed since 2003.

In addition, WHS ministers decided in 2018 to rename the WES list as the Workplace exposure limits for airborne contaminants to communicate that the values are limits not to be exceeded and to align Australia with language used internationally.

Transitioning from the WES to WEL

WHS ministers have agreed to the WEL list and also agreed to a harmonised transition to adopt the WEL list on 1 December 2026, following implementation of the WEL into the WHS laws of the Commonwealth, states and territories.

A summary of differences between the WES list and WEL list can be found here.

What should I do?

If you are a PCBU, you should prepare for the adoption of the WEL during the transition period, ending on 30 November 2026. You should do this by identifying, assessing and controlling the risk posed by the airborne contaminant hazard.

  1. Identifying the hazard – you should consult the WEL list to see what airborne contaminants you use or generate in the workplace and the new limits after 1 December 2026 are. If you are already aware of the airborne contaminants in your workplace, check the WEL list to see if the limit has changed. 
  2. Assess the hazard – You must ensure that no worker is exposed to an airborne concentration of an airborne contaminant that is higher than the WEL. If you unsure about whether you exceed the WEL or not, you must conduct air monitoring
  3. Control the hazard – You should identify and implement appropriate controls to implement to ensure that your workplace does not exceed the WEL. You should always aim to eliminate the airborne contaminants. But if it is not reasonably practicable to eliminate the hazard, then you must minimise the risk posed by the hazard by following the hierarchy of controls. You should review your control measures to make sure they work as planned. 

Next steps

Safe Work Australia (SWA) is currently producing guidance and other material to support the transition to the WEL. These will be published throughout the transitional period and beyond.

From the review and consideration of stakeholder feedback, WHS ministers have requested SWA conduct additional impact analysis for proposed changes to the WES for 9 chemicals: 

  • benzene 
  • chlorine
  • copper (fumes, dusts and mists)
  • formaldehyde
  • hydrogen cyanide 
  • hydrogen sulphide 
  • nitrogen dioxide 
  • respirable crystalline silica
  • titanium dioxide

Work on the additional impact analysis on these chemicals is ongoing. Until this is complete, and a decision has been made by WHS Ministers, the WEL for these chemicals will remain the same as those listed in the WES list.

For updates on the impact analysis process, the release of new and updated guidance material, and updates to the WEL list, subscribe to the mailing list.

If you have questions about your jurisdiction’s implementation of the WEL, contact your WHS regulator

Supporting information

Workplace exposure limits resources

Workplace exposure standards resources

Relevant guidance for WES and WEL