Identifying silica dust risks and hazards in construction

In the first of a series of articles looking at Queensland’s new code of practice for silica dust in construction, we explain how to identify exposure risks at the workplace.

The Managing respirable crystalline silica dust exposure in construction and the manufacturing of construction elements code of practice Code of Practice 2022 (the Code) starts on 1 May 2023. It is a practical guide for PCBUs in construction and related manufacturing, which outlines how to meet their legal requirements to safely manage silica dust at the workplace.

The first step is to identify any risks and hazards caused by silica dust at your workplace. Are any materials containing one per cent or more crystalline silica being used? Do any tasks which involve these materials generate dust containing respirable crystalline silica?

PCBUs must consult workers while they are identifying risks and hazards. Section 4 of the Code provides information on consulting with workers and other duty holders (contractors on site, labour hire companies).

Many common construction materials contain small amounts of crystalline silica, but the new code focuses on materials containing one per cent or more.

• Construction materials which contain one per cent or more crystalline silica include, but are not limited to, bricks, concrete, engineered stone, natural stone (granite or sandstone) and fibre-cement sheets.
• Construction materials which contain no silica at all or less than one per cent crystalline silica include, but are not limited to, wood, glass, metals (iron, steel, copper or aluminium) and most plastics.

Take the following actions to find out if construction materials contain one per cent or more crystalline silica:

• check the technical document or safety data sheet for the material
• contact the manufacturer, supplier or importer
• get the material tested by a National Association of Testing Authorities facility.

If you can’t find out how much crystalline silica is in the material, you should manage the risk on the assumption that it does.

Construction work that involves earthmoving (digging trenches or tunnelling) can also involve a risk of silica dust exposure, as many common materials found underground contain crystalline silica. These include most rocks, sands and clays, granite and sandstone. Section 5.1 of the Code identifies tests to confirm which materials are present in the earth that will be moved, processed or disturbed.

Dust containing respirable crystalline silica can be generated and released into the air during tasks which involve high-energy processing, such as cutting, sawing, grinding, drilling, polishing, scabbling and crushing.

This dust can also airborne after settling in the workplace by:

• using dry sweeping, compressed air or high-pressure water to clean up
• letting slurry dry out before cleaning it up
• allowing excessive dust build-up around equipment and work areas.

Further information

Further information on identifying respirable crystalline silica hazards is provided in Section 5 of the new Code.

All identified hazards must be included in a safe work method statement (construction work) or the workplace’s WHS risk management plan (manufacturing). Dust controls must be implemented to prevent and minimise exposure to RCS dust from these tasks.

Read more about managing respirable crystalline silica hazards at WorkSafe.qld.gov.au.