Research into a lower workplace exposure standard and short term exposure limit for respirable crystalline silica

On 22 March 2024, WHS ministers agreed to Safe Work Australia’s recommendations relating to the ban on the use of engineered stone under the model WHS laws. Read the Ban on the use of engineered stone webpage for more.

Transitional Arrangements

The ban is set to come into effect on 1 July 2024 in most jurisdictions. Jurisdictions will need to implement amendments to their own WHS laws to give effect to the ban on the use of engineered stone. For questions about transitional arrangements and the implementation of the amendments in your jurisdiction, please contact your WHS regulator.

Following a health-based review of the WES for RCS, the 8 hour time weighted average workplace exposure standard (WES) for respirable crystalline silica was recommended to be reduced from 0.1 mg/m3 to 0.02 mg/m3 to minimise the risk of silicosis and lung cancer.

However, submissions to the public consultation for the WES review raised concerns that a WES of 0.02 mg/m3 would be difficult to measure and enforce. 

In 2019, WHS ministers agreed to lower the WES for RCS to 0.05 mg/m3 with implementation in all jurisdictions as soon as practicable, pending further review of the measurability concerns. 

Safe Work Australia investigated the measurability concerns for an 8 hour time weighted average WES for RCS of 0.02 mg/m3, as well as the option of a short term exposure limit (STEL). 

The report into measuring airborne concentrations of RCS found that there was uncertainty in measuring 0.02 mg/m3 with the current sampling and analysis equipment available in Australia. This was due to multiple reasons including sampling error, analytical uncertainty and laboratory reporting and performance. This report recommended that more work be done on measurement standards and laboratory techniques in Australia before the WES for RCS is reduced to 0.02 mg/m3. The full report is available at Measuring respirable crystalline silica.

The report into adding a STEL for RCS did not recommend a STEL if the 8 hour time weighted average WES is 0.05 mg/m3. The report stated that any exposure above 0.05 mg/m3, even for short periods of time, is not recommended and that a STEL would only provide additional protection when used in combination with a WES of 8 hour time weighted average of 0.02 mg/m3. The full report is available at Short Term Exposure Limit for Respirable Crystalline Silica.

Safe Work Australia continues to monitor developments in the measurement of RCS to inform future reviews of the WES.

Supporting information