WES → WEL: Workplace Exposure Limits replace Standards
Status: Upcoming
Effective 1 December 2026. Reference now, treat as binding from that date.
From 1 December 2026, the long-running Workplace Exposure Standards (WES) for airborne contaminants are replaced nationally by Workplace Exposure Limits (WEL). The change updates ~50 substances with reduced or revised limits based on current toxicological evidence, and modernises the framework around short-term excursion limits and biological monitoring. All Australian jurisdictions adopt the WEL list under model WHS Reg 49.
What is changing
Safe Work Australia's Workplace Exposure Standards (WES) for airborne contaminants have governed chemical exposure limits in Australian workplaces for decades. The WEL list, published by SWA in 2024, replaces the WES list nationally on 1 December 2026. The transition affects approximately 50 substances — silica, diesel particulate matter, isocyanates, hexavalent chromium, beryllium, welding fumes, and others — many with significantly reduced limits. The framework also formalises short-term excursion limits (STEL) and ceiling limits for substances where peak exposure matters, and introduces biological monitoring guidance for substances where airborne measurement is unreliable. Until 30 November 2026 the WES list remains binding; from 1 December 2026 the WEL list binds and the WES list is superseded. PCBUs that monitor airborne contaminants must update their measurement protocols and their chemical risk assessments to the new limits.
Timeline
WEL list published by Safe Work Australia.
Final 6-month transition period begins.
WEL binds nationally; WES superseded.
Who it affects
- Construction trades exposed to silica or welding fume
- Manufacturing operations with airborne contaminants
- Healthcare and laboratory operations with chemical exposures
- Transport and logistics operations with diesel exhaust exposure
- Mining operations with crystalline silica or diesel exposure
What you need to do
- 1
Audit your chemical register
Identify substances where the WEL is lower than the WES. These are the substances most likely to require new controls or new monitoring.
- 2
Update your chemical risk assessments
Risk assessments that cite WES values need to be reissued against the WEL values. The assessment date and source are critical for s18 reasonably-practicable reasoning.
- 3
Plan re-monitoring for at-risk substances
For substances where you have historic WES exceedances, plan re-monitoring against the WEL before 1 December 2026 to establish a baseline.
- 4
Brief workers on the change
Workers exposed to airborne contaminants need to understand that limits are tightening and what new controls (substitution, ventilation, RPE) are being applied.
How RAE IQ handles it
RAE IQ's chemical register and chemical risk assessment module already track WES and WEL values side-by-side. From 1 December 2026 the engine automatically surfaces the WEL as the binding limit; chemical risk assessments generated before that date capture both values with the effective-date stamp so the historical record remains defensible. The citation supersession scanner notifies organisations with affected chemicals in their register.
Related glossary terms
Industries most affected
Tracked, cited, and ready when the date flips.
Every change on this page is wired into RAE IQ's drafting engine — when the effective date hits, the documents it generates change too.