When crushing large rocks, concrete, or construction rubble with crushing machines, there is a potential to generate respirable crystalline silica dust. Inhaling these small silica particles over time can cause irreversible damage to the lungs.

WorkCover Queensland recommends the following exposure controls in accordance with Appendix 4 of the Managing respirable crystalline silica in construction and manufacturing of construction elements code of practice 2022 (PDF, 1.71 MB):

Use suitable engineering controls

Consider the following engineering control options:

• Utilize equipment with water spray or mist for dust suppression at crusher and other dust-generating points.
• Choose either a ventilated booth providing fresh, climate-controlled air to the operator or a remote-control station.

Details of controls: Using water sprays or mists for dust suppression at points where dust is generated (such as hoppers, conveyors, sieves/sizing, vibrating components, and discharge points) effectively controls dust exposures during crusher operations. Additionally, operator isolation methods, such as enclosed booths or remote-control stations, must be implemented. It is crucial to operate and maintain the crusher according to the manufacturer’s instructions to minimize dust emissions.

Operator isolation:

• Enclosed booth: Operators can limit silica exposure by staying inside the ventilated booth during crushing operations. The booth should be well-sealed, well-ventilated, use positive pressure, have properly functioning joints, and include heating and air conditioning.
• Remote-control station: Alternatively, a remote-control station positioned upwind at a sufficient distance can be used for operator isolation, limiting exposure to silica-containing dust.

Select appropriate respiratory protective equipment (RPE)

The need for respiratory protective equipment (RPE) depends on:

• The chosen engineering controls.
• The duration of the task during the shift.
• The location of the work.

When properly used, wet methods with ventilated booths or remote-control stations can effectively limit exposure to airborne dust. The use of respiratory protection is not required when crushers are equipped with water sprays along with either control booths or remote-control stations at construction sites.