Changed numerical limits
Some airborne contaminants move to lower or higher values. A lower value may materially change which existing monitoring or control arrangements need review.
WES → WEL 2026 · Transition guide
What changes on 1 December 2026?
Australia's harmonised transition to Workplace Exposure Limits is scheduled for 1 December 2026. The WEL list replaces the current WES list, with several different kinds of change to check rather than one simple across-the-board conversion.
Before the transition
The existing WES list continues to apply through 30 November 2026. Safe Work Australia says the WEL list is to be adopted from 1 December 2026 following implementation into Commonwealth, state and territory WHS laws.
The main categories of change
Changed limit type
Some entries change the way the limit is expressed, including combinations of time-weighted average, short-term exposure and peak-limit treatment.
New entries
The WEL list contains contaminants that were not separately listed in the previous WES structure. Some relate to contaminants generated by work processes rather than chemicals purchased into an inventory.
Removed entries
Some former WES entries are removed or reorganised. Removal from a list should not be read as a statement that the hazard has disappeared.
Merged, split and renamed entries
A substance name can map differently between the old and future lists. Form, fraction or chemical grouping can matter, so a name-only one-to-one match is not always appropriate.
Notation changes
Safe Work Australia's transition material also records notation changes, including the move from SEN to more specific DSEN and RSEN notation, introduction of OTO and removal of CARC notation.
Two special transition cases
Thirty-three NTGC substances move away from numerical WEL treatment. Separately, a 24 June 2026 ministerial decision means the proposed new numerical limits for nine chemicals will not take effect on 1 December 2026; their exposure levels remain at their current WES levels for the transition.
33 NTGC substances →
Nine exposure levels not changing →
Why a chemical inventory is useful but incomplete
An inventory can help identify purchased substances whose listings change. It may not capture contaminants generated by tasks or processes, such as dusts, fumes, vapours or emissions. Safe Work Australia specifically advises workplaces to identify contaminants they use or generate.
Why process-generated contaminants need a separate check →
Screen your inventory
If you already have a CSV or spreadsheet chemical inventory, BecSpec's experimental screener can flag entries that match published WES→WEL transition evidence. Review and unresolved states are intentional where form, fraction or identity is uncertain.
Official sources
Safe Work Australia — Workplace Exposure Limits ↗
Safe Work Australia — Changes between WES and WEL ↗