WES to WEL: the Workplace Exposure Limits transition on 1 December 2026

On 1 December 2026, Australia transitions from Workplace Exposure Standards (WES) to Workplace Exposure Limits (WEL). For organisations that handle hazardous chemicals (which includes most manufacturing, construction, healthcare, agriculture, cleaning and laboratory work) this is the biggest change to chemical safety in two decades.

What's changing

Three things, in plain English:

1. Lower numbers for many substances.Safe Work Australia's review tightened exposure limits for around 250 substances, often by a factor of 2–10×. Crystalline silica, welding fume, diesel particulate, formaldehyde and isocyanates are on that list.
2. New substances added.About 40 chemicals that weren't on the WES list now have a WEL. If you've been assuming “not on the list = no limit”, that assumption breaks on 1 December.
3. Tighter peak limits. Short-term exposure limits (STEL) and ceiling values were reviewed alongside the 8-hour time-weighted average (TWA) numbers. Some peak limits are significantly tighter than before.

Where this hits hardest

• Welding and metal fabrication. Welding fume limit dropped to 1 mg/m³ TWA in 2024. The 2026 transition reinforces this and adds tighter limits for several constituent metals (manganese, hexavalent chromium, nickel).
• Construction (silica). The respirable crystalline silica limit has been tightened progressively; WEL formalises the regime nationally and adds enforcement teeth.
• Healthcare and laboratories. Formaldehyde, ethylene oxide, glutaraldehyde and several anaesthetic gases have new lower limits.
• Cleaning and facilities. Isocyanate limits in two-pack paints and some industrial cleaning products are tighter.

What you need to do

1. Pull every chemical in your chemical register and identify which ones have a WEL change: tightened TWA, new STEL, new ceiling, or first-time inclusion.
2. Review your existing exposure controls for each affected chemical. A control that delivered “below WES” may not deliver “below WEL.” Hierarchy of controls applies: prefer elimination or substitution before tightening engineering controls or PPE.
3. Re-run your chemical risk assessments for affected substances. The legislative reference and the limit itself both change.
4. Update your health monitoring programme. New chemicals may trigger health monitoring obligations for the first time.
5. Update SDS expiry tracking. You want every SDS reviewed against the new limits before 1 December.

What RAE IQ does about it

The chemical register on RAE IQ is built on GHS classification with a per-chemical limit field that maps to the current WES today and the WEL from 1 December 2026. We surface affected chemicals as the transition dates pass, so you don't have to manually walk through 250 substances.

Chemical risk assessments drafted after 1 December cite WEL directly; assessments drafted before that date cite WES with a flag indicating the impending change.

The honest part

WEL is not a new platform problem. It's a real-world problem that requires real-world re-engineering of exposure controls for the substances most relevant to your operations. The platform helps you find the affected chemicals quickly and document your decisions. The actual control changes (better extraction, lower-VOC products, better PPE) are work that has to happen on the floor.

If you want to see which of your chemicals are affected, start free and upload your chemical list. The register will tag each one with current WES and incoming WEL.