Information only
This tool is not a WHS risk assessment, not exposure monitoring and not professional advice. It compares names and CAS numbers against a dataset of WES and WEL values. A match does not mean a worker is over or under a limit. Check every result against the official Safe Work Australia WEL list and WES list. If you need to know actual exposures, talk to an occupational hygienist.
1. Add your register
Paste one substance per line, or copy columns straight from Excel. CAS numbers give the most reliable match. Product rows with several CAS numbers, e.g. Brake cleaner, 108-88-3; 67-64-1, are split automatically.
Or upload a file: CSV, TSV, TXT or Excel (.xlsx, first sheet).
The file is read on your device. It is not sent anywhere.
2. Results
| Row | Your entry | Matched substance | Match | Current WES to 30 Nov 2026 |
WEL from 1 Dec 2026 |
Change | Source & notes |
|---|
"Verify" means the match is on a name, not a CAS number. Confirm the CAS number in section 3 of the SDS before you rely on it.
Questions
What is changing on 1 December 2026?
Safe Work Australia's Workplace Exposure Standards (WES) list is replaced by the Workplace Exposure Limits (WEL) list. Most values don't change. Some limits are lower, a few are higher, new substances are added, and substances classed as non-threshold genotoxic carcinogens lose their numerical limit, so exposure has to be eliminated or minimised instead. Until 1 December 2026, the WES list still applies. Source: Safe Work Australia.
Does my register leave my computer?
No. The page downloads the comparison data once, and all matching happens in your browser. We use GoatCounter, which sets no cookies, to count page views and how many checks are run. A check is counted as one event named "register-check", with no register contents. You can confirm this in your browser's network tab.
How does matching work?
CAS numbers are matched exactly after their check digit is validated. If there's no CAS number, or the CAS isn't in the dataset, we try the substance name and common synonyms, then close spellings. Every name-based match is marked "verify".
Can I look up one substance?
Yes. There is a page for each of the substances in the dataset, with the current WES, the WEL from 1 December 2026, notation changes and what to update in your register. See all substances, A to Z.
Where does the data come from?
Safe Work Australia's own publications: the WES list and the WEL list (both as amended November 2025), the "Changes to Workplace Exposure Limits" comparison table, and the June 2026 Decision RIS on 9 chemicals. © Commonwealth of Australia, licensed under CC BY 4.0. What we changed: the values are machine-read from SWA's files, reformatted, and combined into one WES-to-WEL comparison per substance, with entries that share a CAS number grouped. Every value was cross-checked against the PDF versions of the lists and the comparison table. This site isn't affiliated with or endorsed by Safe Work Australia.