Frequently asked questions - Silica
This page provides information for employers and employees about silica and some of the legal duties relating to protecting workers from developing silicosis.
Silica is found in sand, stone, concrete and mortar. It is also used in the manufacture of a variety of products including composite stone used to fabricate kitchen and bathroom benchtops, bricks, tiles and some plastics. When workers cut, crush, drill, polish, saw or grind products that contain silica, very small dust particles (not necessarily visible to the eye) are generated that are small enough to lodge deep in the lungs and can cause illness or disease including silicosis. These very small dust particles are referred to as respirable crystalline silica (RCS).
What is RCS?
Silica dust is generated in mechanical processes such as crushing, cutting, drilling, grinding, sawing or polishing of natural stone or man-made 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.
Why is exposure to RCS dangerous?
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.
What is the new RCS Exposure Standard?
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.
What controls should I be using?
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 –
Can I wear a fitted respirator if I have stubble or a beard?
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.
Can my employer require me to shave if a fitted respirator is required?
Yes. An employer should have a policy in relation to PPE requirements and this may include that employees who need to wear fitted respirators be clean shaven.
Is dry cutting banned?
Uncontrolled dry cutting (ie dry cutting without local exhaust ventilation on-tool) is non-compliant and WorkSafe inspectors will take enforcement action where this practice is identified.
If controlled dry cutting (using LEV) is being conducted, do other workers in the vicinity need to be protected?
Yes, as dry cutting with local exhaust ventilation 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.
Is slurry from wet cutting a problem?
Slurry from wet cutting materials containing silica must be adequately managed. 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. If slurry is allowed to dry out and dust is generated, people can be exposed to airborne RCS.
When is health surveillance for RCS exposure required?
Health surveillance 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 surveillance will need to be provided for workers working in the stone fabrication industry.
Health surveillance may not be required for occasional tasks generating RCS, where controls are in place.
What activities generate high levels of RCS?
Examples of work activities that can generate respirable 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
Do I need to measure the level of exposure to RCS?
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;
- 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.
Who can conduct air monitoring?
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 may be of limited use or not useful.
- Checklist – Stone benchtop fabrication and installation
- Guidance Note – Safe stone product fabrication and installation
- Safety Alert - Stone benchtop workers at risk of silicosis
- Mines Safety Bulletin – Reducing exposure to respirable crystalline silica (quartz)
- Guidance on the interpretation of workplace exposure standards for airborne contaminants - Safe Work Australia
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