Silica dust is generated in mechanical processes such as crushing, cutting, drilling, grinding, sawing or polishing of natural stone or manufactured products that contain silica, such as engineered stone, concrete and bricks. Some of the dust particles generated can be so small that they are not visible. Due to their small size they can penetrate deep into the lungs. These very fine particles are referred to as respirable crystalline silica or RCS.

RCS dust particles are small enough to penetrate deep into the lungs where they can cause scarring of the lungs, silicosis and lung cancer. Symptoms of silicosis include a persistent cough, shortness of breath and tiredness. Silicosis can be fatal.

Workers must not be exposed to respirable crystalline silica levels above the exposure standard of 0.05 mg/m³ for a standard eight hour shift. 

Choose wet cutting or grinding systems or systems with engineering controls such as local exhaust ventilation (LEV) fitted to the equipment to reduce airborne RCS. Using wet systems and LEV together further reduces airborne RCS. Respiratory protective equipment may still be needed even if other controls are used. More information –

• Checklist – Stone benchtop fabrication and installation 
• Code of Practice - Managing the risks of respirable crystalline silica from engineered stone in the workplace 
• Safety Alert - Stone benchtop workers at risk of silicosis
• Mines Safety Bulletin – Reducing exposure to respirable crystalline silica (quartz)

No. Facial hair or stubble along the seal of the respirator reduces the effectiveness of the respirator, and as a result the wearer may be exposed to RCS during their work activities. A fitted respirator requires fit testing to check that it will protect the user – see the Information sheet – fit testing.

Yes. For engineered stone, r. 184A of the Work Health and Safety (General) Regulations 2022 prohibits cutting, grinding or abrasive polishing unless there is an integrated water control or on-tool dust extraction, or if these are not practicable, local exhaust ventilation. For other silica containing material, uncontrolled dry cutting (ie dry cutting without on-tool extraction or local exhaust ventilation) is non-compliant under S. 19 of the Work Health and Safety Act 2020, and WorkSafe inspectors will take enforcement action where this practice is identified.

Yes, as dry cutting with on tool extraction can still produce significant quantities of RCS (exceeding the workplace exposure standard), the operator and others in the work area all need to wear suitable respirators.

Yes - if slurry is allowed to dry out and dust is generated, people can be exposed to airborne RCS.  Slurry can be managed through the use of on-tool attachments to remove the slurry as it is being produced or by cleaning the slurry whilst wet. 

Health monitoring is required in any situation where the workers’ health is at risk as a result of exposure to RCS. Further information can be found here.

In most cases health monitoring will need to be provided for workers working in the stone fabrication industry, even if standard controls such as wet cutting and respirators are in place. This is because even low exposure to RCS presents a risk.

Health monitoring may not be required for occasional tasks generating RCS, where controls are in place.

Examples of work activities that can generate respirable crystalline silica dust particles include:

• fabrication and installation of engineered stone or natural stone
• construction activities such as chasing (brick, concrete or stone cutting) and angle grinding, jack hammering and chiselling of concrete or masonry
• excavation, earth moving and drilling plant operations
• clay and stone processing machine operations
• paving and surfacing
• foundry casting
• crushing/milling of ore samples at assay laboratories

Air monitoring is important to help you understand the level of risk and whether or not your current controls are adequate.

Your risk assessment will help you to work out if you need to engage a competent person (such as an occupational hygienist) to do air monitoring. Some indicators of a need for monitoring may include: 

• frequent or long duration of a process which generates dust or mist containing silica (for example, stone manufacturing workshops); 
• efficiency of ventilation is not known or no mechanical ventilation; or 
• it is a complex work environment and it is difficult to estimate exposure.

If there are visible dust clouds, controls should be improved prior to conducting monitoring as the workplace exposure standard for silica is very likely to be exceeded. Even where wet methods are used, exposure may be significant.

If in doubt, consult an occupational hygienist for advice. 

Air monitoring should be conducted by a competent person such as an occupational hygienist. The monitoring strategy should be determined by the competent person to ensure that important factors, such as assessment of different work roles, sampling to account for seasonal or other work rate variability and sample size are factored in. Air monitoring that has not been conducted by a competent person is of limited or no use.