Changes between the WES and WEL

There are several changes between the Workplace exposure standards for airborne contaminants (WES list) and the Workplace exposure limits for airborne contaminants (WEL) as a result of the WES Review. This webpage outlines the key changes that you should know about.

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.

Renaming ‘exposure standards’ to ‘exposure limits’

The Workplace exposure standards for airborne contaminants will be renamed Workplace exposure limits for airborne contaminants. This change has been made to communicate that the values are limits not to be exceeded and to align Australia with language used internationally.

There are no changes to your obligations under the model work health and safety (WHS) regulations as a result to this change. If you are a person conducting a business or undertaking (PCBUs), you must continue to ensure that no person at the workplace is exposed to a substance or mixture above its workplace exposure standard until 30 November 2026.

From 1 December 2026, you must ensure that no person at the workplace is exposed to a substance or mixture above its workplace exposure limit.

Changes to individual exposure limits and notations

The revised WEL follows the completion of the review of the workplace exposure standards and agreement by WHS ministers. While most exposure limits remained unchanged, changes that have been agreed to are:

  • a reduction in 160 exposure limits.
  • an increase in 11 exposure limits.
  • amendments to 79 exposure limits, including:
    • the introduction or removal of a time weighted average (TWA), short term exposure limit (STEL) or peak limitation,
    • the merging of multiple pre-existing exposure standards into a singular WEL,
    • the splitting a pre-existing exposure standard into 2 separate WELs to account for differences in the inhalation or respirable fraction.
  • the introduction of exposure limits for 30 airborne contaminants.
  • the removal of 6 airborne contaminants from the WEL list.

Thirty three chemicals have been moved out of the WEL list into a new list in recognition that they are non-threshold genotoxic carcinogens. More information on these airborne contaminants is provided below.

You should check the WEL list to see if the limits for the airborne contaminants you work with or generate in the workplace have changed. See the workplace exposure limits – airborne contaminants webpage for more information on what you should do if are affected by any changes.

If you work with an airborne contaminant where the exposure limit has been increased, removed, amended or moved, you can only comply with these changes from 1 December 2026. Prior to 1 December 2026, you must still comply with the current exposure standards in the WES list.

Changes to advisory notations

Advisory notations inform you of additional health risks that the airborne contaminants pose to workers. Some advisory notations have been updated in the WEL list for individual chemicals.

In addition to the above, there have also been broader changes to the advisory notations, including:

  • changes to the sensitisation notation (SEN)
  • addition of the ototoxicity notation (OTO)
  • removal of the carcinogenicity notation (CARC)

You should check the notations for any airborne contaminants you may work with or generate in your workplace.

Changes to the sensitisation (‘SEN’) notation

In the WEL list, the pre-existing sensitisation (‘SEN’) notation has been split into dermal (skin) sensitisation (‘DSEN’) and respiratory sensitisation (‘RSEN’).

These notations will provide you with more clarity as to what form of sensitisation may affect your workers and better inform you of the appropriate controls to have in place to limit exposure:

  • ‘DSEN’ indicates if the airborne contaminant can cause an allergic response after contact with skin.
  • ‘RSEN’ indicates if the airborne contaminant can cause hypersensitivity of the airways after inhaling the airborne contaminant.

Addition of ototoxicity (‘OTO’) notations to WEL list

An ototoxicity notation (‘OTO’) has been introduced into the WEL list for certain airborne contaminants. Exposure to an airborne contaminant with an ‘OTO’ notation can increase the risk of hearing loss, especially if a worker is also exposed to noise at the same time.

For more information on ototoxic chemicals, refer to the model Code of Practice: Managing noise and preventing hearing loss at work.

Removal of carcinogenicity (‘CARC’) notations from WEL

Carcinogenicity notations were included in the WES list to inform PCBUs and workers if the airborne contaminant can cause cancer or is suspected of causing cancer.

Carcinogenicity notations have been removed from the WEL. This is because the carcinogenicity notations only tell you and your workers of a possible hazard property and classification. It does not influence or impact exposure levels in the workplace and does not inform you or your workers of more immediate risks.

To find out if the airborne contaminant you work with or generate in the workplace may cause cancer or is suspected of causing cancer, you should refer to the airborne contaminant’s safety data sheet (SDS) or the Hazardous Chemical Information System (HCIS).

Non-threshold genotoxic carcinogens (NTGCs) in the WEL

The Review of Workplace exposure standards identified that 33 airborne contaminants are non-threshold genotoxic carcinogens (NTGC). These airborne contaminants have no safe exposure limit, meaning any exposure, even for a short period of time, can result in a person developing cancer.

From 1 December 2026, there will no longer be exposure limits for these airborne contaminants. They have been included in a separate list in the WEL. These airborne contaminants are:

  • Acrylamide
  • Acrylonitrile (Vinyl cyanide)
  • Allyl chloride (3-Chloro-1-propene)
  • Allyl glycidyl ether (AGE, Allyl 2,3-epoxypropyl ether)
  • Anisidine (o, p- isomers) (Methoxyaniline)
  • o-Anisidine
  • p-Anisidine
  • Benzidine
  • (bis)chloromethyl ether
  • 1,3-Butadiene
  • Catechol (Pyrocatechol, o-Dihydroxybenzene)
  • beta-Chloroprene (2-Chloro-1,3-butadiene)
  • Chromium VI compounds (including zinc chromates)
  • Coal tar pitch volatiles (as benzene solubles)
  • 1,2-Dibromo ethane (ethylene dibromide)
  • 3,3′-Dichlorobenzidine
  • Diethyl sulfate
  • Dimethycarbamoyl chloride
  • Dimethyl sulfate
  • Dinitrotoluene
  • Ethylene dichloride (1,2-Dichloroethane)
  • Ethylene oxide (Oxirane)
  • Ethylenimine (Aziridine)
  • Hydrazine (Diamine)
  • Lead chromate (as Cr)
  • 4,4’-Methylene bis(2-chloroaniline) (MOCA, MBOCA, 2,2′-Dichloro-4,4′-methylenedianiline)
  • 2-Nitrotoluene
  • Propane sultone
  • Polycyclic aromatic hydrocarbon (PAH) mixture when containing benzo[a]pyrene
  • Tetranitromethane (TNM)
  • Urethane
  • Vinyl Bromide (Bromoethylene)
  • Vinyl chloride, monomer (Chloroethylene)

As part of the transition to the WEL, PCBUs must continue to:

  • ensure that no person in the workplace is exposed to levels above the current respective WES for these chemicals, and
  • eliminate the risks of exposure to any NTGC(s) used or generated in the workplace so far as is reasonably practicable, or
  • if it is not reasonably practicable to eliminate the NTGC(s), minimise the risks for far as is reasonably practicable.

You must also continue to comply with your obligations under Schedules 10 and 14 of the model WHS Regulations if the NTGCs used or generated in the workplace are listed.

Supporting information