Hazards + exposures
We checked all nine deadlocked chemicals against the new national database. Every one carries its old number
In June, work health and safety ministers could not reach a majority to tighten the exposure standards for benzene, respirable crystalline silica and seven other chemicals, so those standards carry over unchanged when workplace exposure limits take legal effect on 1 December 2026. Safe Work Australia has since published the database that will carry them. We queried it directly, chemical by chemical, and read the approved record for each. All nine match the carried-over values. The database also supplies detail the decision notice did not: the milligram equivalents, the size fractions, and the fact that copper is not one entry but two.
This follows our July piece on the nine chemicals ministers could not agree on. That story reported a decision. This one checks whether the system built to carry that decision actually does, which is a different question and, six weeks before a legal deadline, the more useful one.
On 4 August Safe Work Australia replaced the Hazardous Chemical Information System, the national register of hazardous chemical data. The new HCIS is where a duty-holder looks up what limit applies to a substance. From 1 December those limits stop being advisory standards and become workplace exposure limits with legal force.
What the register says for each of the nine
Values are from the approved and active record for each chemical in the new HCIS, read on 6 August 2026. Where the register holds more than one approved record for a substance, as it does for copper, both are shown. The right-hand column is what we reported in July as the standard that carries over.
| Chemical | Fraction | In the new register | Carried-over standard, as we reported it |
|---|---|---|---|
| Benzene | Inhalable | TWA 1 ppm (3.2 mg/m³) | TWA 1 ppm |
| Chlorine | Inhalable | Peak 1 ppm (3 mg/m³) | Peak 1 ppm |
| Copper | Fume | TWA 0.2 mg/m³ | TWA 0.2 mg/m³ (fumes) |
| Copper | Dusts and mists | TWA 1 mg/m³ | TWA 1 mg/m³ (dusts and mists) |
| Formaldehyde | Inhalable | TWA 1 ppm (1.2 mg/m³); STEL 2 ppm (2.5 mg/m³) | TWA 1 ppm; STEL 2 ppm |
| Hydrogen cyanide | Inhalable | Peak 10 ppm (11 mg/m³) | Peak 10 ppm |
| Hydrogen sulphide | Inhalable | TWA 10 ppm (14 mg/m³); STEL 15 ppm (21 mg/m³) | TWA 10 ppm; STEL 15 ppm |
| Nitrogen dioxide | Inhalable | TWA 3 ppm (5.6 mg/m³); STEL 5 ppm (9.4 mg/m³) | TWA 3 ppm; STEL 5 ppm |
| Quartz (SiO2) | Respirable | TWA 0.05 mg/m³ | TWA 0.05 mg/m³ |
| Titanium dioxide | Inhalable | TWA 10 mg/m³ | TWA 10 mg/m³ |
Nine for nine. There is no gap between what ministers decided and what the register will enforce, which is worth establishing rather than assuming, because the two have been known to drift apart and nobody would have noticed here until someone was measured against the wrong number.
Three things the register adds
The milligram equivalents. A limit expressed in parts per million is not what an air-monitoring laboratory reports. The register carries both, so benzene at 1 ppm is also 3.2 mg/m³, and hydrogen sulphide at 10 ppm is 14 mg/m³. If you are reading a monitoring result, that second column is the one you need.
Copper is two entries, not one. The register holds separate approved records for copper fume at 0.2 mg/m³ and copper dusts and mists at 1 mg/m³, a five-fold difference turning on the physical form. A duty-holder who looks up "copper" and takes the first number they see has a one-in-two chance of applying a limit five times too generous.
Two of the nine are peak limitations, not averages. Chlorine and hydrogen cyanide carry no eight-hour average at all. Their limits are peak limitations, which Safe Work Australia defines as the maximum concentration measured over the shortest time possible and in any case no more than 15 minutes. An eight-hour average is the wrong instrument for both, and a compliant-looking TWA result says nothing about whether either limit was breached.
Silica is in there under a name you may not search for
Respirable crystalline silica appears in the register as Quartz (SiO2) (respirable fraction), at TWA 0.05 mg/m³. That is the same limit, under the mineral's name rather than the hazard's. Anyone searching the new system for "silica" and concluding it is absent has searched for the wrong string, and given how much construction and stone work now turns on that number, it is worth knowing before 1 December rather than after.
Our view, labelled as such
The carry-over itself is not good news, and we said so in July: nine chemicals were assessed as warranting tighter limits and did not get them. Nothing in the register changes that.
What the register does change is that the position is now checkable. Six weeks out from a legal deadline, any duty-holder can confirm the number that will apply to them rather than infer it from a decision notice, and any discrepancy between the two would now be visible. That is a meaningfully better position than the one we described in July, and it is the sort of thing that usually goes unremarked because nobody looks.
How we checked this
We queried the new HCIS directly for each of the nine chemicals using its CAS registry number rather than its name, and read the approved, active record returned for each. The register keeps versions: alongside each approved record sit draft and superseded ones for the same substance, so the figures above are specifically the record marked approved and active at the time of reading. Benzene, for example, holds four records, of which the live one was approved on 31 July 2026. The right-hand column of the table is our own July reporting, reproduced so the two can be compared line by line, and the definitions of time-weighted average, short-term exposure limit and peak limitation are Safe Work Australia's own from the register's reference pages.
What we have not done. We have not put any of this to Safe Work Australia, and we are not reporting a defect, because we found none: the point of the exercise was to test agreement and the agreement holds. We have not audited the whole register, only these nine chemicals, so nothing here says anything about the roughly eleven hundred other substances it carries. We have not read the per-chemical evaluation reports the register references, only the values themselves. This is general information about what the register states, not advice on compliance for any particular workplace, and the limits take legal effect on 1 December 2026 rather than today.
Sources
- Safe Work Australia, Hazardous Chemical Information System (the new HCIS, published 4 August 2026; workplace exposure limit records queried directly and read 6 August 2026): the approved and active exposure limit record for each of the nine chemicals in the table, including the parts-per-million and milligram-per-cubic-metre values, the size fractions, the two separate copper records, and the entry for quartz.
- Safe Work Australia, Workplace exposure limits reference (read 6 August 2026): that the limits come into effect from 1 December 2026, and the definitions of the three limit types, being the eight-hour time weighted average, the short-term exposure limit measured over 15 minutes, and peak limitation measured over the shortest time possible and no more than 15 minutes.
- Australian Workplace Safety, the nine chemicals ministers could not agree on: our July report of the decision, and the carried-over standards reproduced in the right-hand column above.