Crystalline silica

Sources of exposure

When is crystalline silica dangerous?

In situ crystalline silica such as soil, rocks, natural and engineered stone, installed bricks, pavers, concrete and tiles, do not present a risk to health if left undisturbed.

When stone, rock or manufactured materials containing crystalline silica undergo mechanical processes such as crushing, cutting, drilling, grinding, sawing or polishing, they can generate very small sized crystalline silica dust, known as respirable crystalline silica (RCS). It is the RCS generated from this processing that has the potential to cause harm.

RCS when breathed in can penetrate deep into the lungs and cause irreversible lung damage. The higher the crystalline silica content of the material being processed, the greater the risk of exposure to RCS.

Workers and other persons can also be exposed to RCS from poor housekeeping methods that disturb dust on workplace surfaces, such as when dry sweeping, using compressed air or high-pressure water cleaners and general-purpose vacuum cleaners not designed for hazardous dusts.

RCS can be generated when undertaking work on silica containing materials such as:

• during manufacturing and construction
• when using sand-based products
• in materials brought to your workplace
• during fabrication and installation of composite (engineered or manufactured) stone countertops
• excavation, earth moving and drilling plant operations
• clay and stone processing machine operations
• paving and surfacing
• mining, quarrying and mineral ore treating processes
• tunnelling
• construction labouring activities
• brick, concrete or stone cutting; especially using dry methods
• abrasive blasting (blasting agent must not contain greater than 1 percent of crystalline silica)
• foundry casting
• angle grinding, jack hammering and chiselling of concrete or masonry
• hydraulic fracturing of gas and oil wells
• pottery making
• concrete cutting
• crushing, loading, hauling and dumping of rock
• clean up activities such as dry sweeping and disposal of waste
• demolition activities.

Workplace exposure standards

Exposure to substances or mixtures in the workplace can occur through inhalation, absorption through the skin or ingestion. Most exposure occurs through the inhalation of vapours, dusts, fumes or gases. For some chemicals, absorption through the skin may also be a significant source of exposure.

Exposure standards have been established in Australia for around 700 substances and mixtures. The standards are updated occasionally and may not always reflect the latest research or state of knowledge on the hazardous effects of chemicals.

Exposure standard means an exposure standard listed in the Workplace exposure standards for airborne contaminants (WES) and represents the airborne concentration of a particular substance or mixture that must not be exceeded. There are three types of exposure standards:

1. eight-hour time-weighted average (TWA)
2. short-term exposure limit (STEL)
3. peak limitation.

The WES for respirable crystalline silica in the Comcare jurisdiction is a TWA of 0.05 mg/m³. The exposure standard was halved from a TWA of 0.1 mg/m³ on 1 July 2020 following agreement by jurisdictional work health and safety ministers and an extensive review by Safe Work Australia.

Silica-related diseases

RCS is a significant health hazard for workers. A person is exposed to RCS whenever the RCS is airborne, and the person can breathe it in. When airborne, workers can breathe RCS particles deep into their lungs where they can lead to a range of respiratory diseases, including:

• acute silicosis
  • can develop after a short exposure to very high levels of silica dust, within a few weeks or years, and causes severe inflammation and an outpouring of protein into the lung
• accelerated silicosis
  • can develop after exposures of 3 to 10 years to moderate to high levels of silica dust and causes inflammation, protein in the lung and scarring of the lung (fibrotic nodules)
• chronic silicosis
  • can develop after long term exposure to lower levels of silica dust and causes fibrotic nodules and shortness of breath
  • can include progressive massive fibrosis where the fibrotic nodules in the lung aggregate
• chronic bronchitis
• emphysema
• lung cancer
• kidney damage
• scleroderma
  • a disease of the connective tissue of the body resulting in the formation of scar tissue in the skin, joints and other organs of the body.

Note: Dust can be a problem in almost any industry. Whilst the hazards of RCS are well recognised, there are many more substances that when present in dusts are hazardous to health. Exposure to all dusts needs to be eliminated, and if it is not reasonably practicable to eliminate exposure, it must minimised so far as is reasonably practicable.

Legacy engineered stone

Prohibition of legacy engineered stone

Commonwealth, state and territory Work Health and Safety Ministers have agreed to Safe Work Australia’s recommendation to prohibit the use of all engineered stone to protect the health and safety of workers. The prohibition commenced on 1 July 2024.

It is an offence under the WHS Regulations for a PCBU to carry out, or direct or allow a worker to carry out, work involving the manufacture, supply, processing or installation of legacy engineered stone benchtops, panels and slabs.

Engineered stone is defined in the WHS Regulations as a crystalline silica substance (CSS) that is an artificial product containing 1% or more crystalline silica (as a weight/weight concentration) that is created by combining materials such as natural stone, water, resins, or pigments and becomes hardened.

The prohibition does not apply to porcelain and sintered stone products (including benchtops, slabs and panels). It also does not include finished engineered stone products that do not need to be processed or modified such as jewellery, garden ornaments, sculptures, and kitchen sinks.

Additionally, the prohibition does not apply to other artificial products including:

• concrete and cement products,
• bricks, pavers and other similar blocks,
• ceramic wall and floor tiles,
• roof tiles,
• grout, mortar and render, and
• plasterboard.

The prohibition also does not apply to natural stone benchtops, panels or slabs. For example, the manufacture, supply, installation or processing of a granite benchtop is not prohibited. However, PCBUs still owe a duty to ensure the health and safety of workers who are processing natural stone products. Also, because natural stone such as granite is a type of CSS, PCBUs must meet the duties that apply to work involving the processing of a CSS. Please refer to the Working with crystalline silica substances: Guidance for PCBUs.

There are limited exceptions to the prohibition where work is permitted on engineered stone benchtops, panels and slabs. This includes:

• for the purposes of genuine research and to sample and identify engineered stone,
• the removal, repair and minor modification to previously installed engineered stone, or
• disposal of engineered stone (that is, after removal or disposal of uninstalled stock).

To support the prohibition, two national frameworks have been established:

• a notification framework under which PCBUs must notify the relevant WHS regulator if they are proposing to carry out permitted work to remove, dispose of, repair or make minor modifications to legacy engineered stone, and
• an exemption framework that provides a process for a WHS regulator to exempt a type of engineered stone from the ban where there is compelling evidence that it can be worked with safely.

Information on the notification framework can be found at Engineered stone notifications. Information on the exemption's framework can be found in the Regulatory guide: Engineered stone prohibition exemption.

Controlled processing of legacy engineered stone

For any permitted work with legacy engineered stone, the processing must be controlled.

Under the WHS Regulations, PCBUs must not process, or direct or allow workers to carry out processing of legacy engineered stone (regardless of whether it is high risk or not) unless the processing is controlled.

For more information, Safe Work Australia has published resources on its Engineered stone ban webpage.

Crystalline silica substances

Crystalline silica substances (CSS) are defined in the WHS Regulations as a material containing at least 1% crystalline silica (by weight).

Examples of a CSS include, but are noy limited to:

• natural stone products such as marble or granite benchtops
• engineered stone
• sintered stone
• porcelain and ceramic products
• sandstone
• asphalt
• cement products containing fly ash, mortar and grout
• bricks, blocks, pavers, tiles and mortar
• concrete and cement-cased products such as fibre-cement sheeting and autoclaved-aerated concrete
• most rocks, sands and clays, and
• composite dental fillings.

Crystalline silica content in a products or substance can be identified by referring to the relevant safety data sheet (SDS). Where a SDS is not available, other sources including product information of technical data sheets may be consulted.

Crystalline silica processes

On 1 September 2024, amendments to the WHS Regulations commenced which provide stronger regulation of work with all materials containing at least 1% crystalline silica, including engineered stone.

Any work with materials containing crystalline silica must be undertaken in a way that eliminates or minimises risks so far as is reasonably practicable.

The WHS Regulations include specific control measures for processing of all crystalline silica substances (CSS) containing 1% or more crystalline silica (weight/weight concentration) that must be implemented to ensure the processing is controlled.

Processing in relation to CSS means:

1. the use of power tools or mechanical plant to carry out an activity involving the crushing, cutting, grinding, trimming, sanding, abrasive polishing or drilling of a CSS; or
2. the use of roadheaders to excavate material that is a CSS, or
3. the quarrying of a material that is a CSS, or
4. mechanical screening involving a material that is a CSS, or
5. tunnelling through a material that is a CSS, or
6. a process that exposes, or is reasonably likely to expose, a person to RCS during the manufacture of handling of a CSS.

The definition is designed to capture all activity with a CSS that has the potential to generate and expose workers and others at the workplace.

High risk crystalline silica process

The WHS Regulations define high risk, in relation to the processing of a CSS, as the processing of a CSS that is reasonably likely to result in a risk to the health of a person at the workplace.

Determining if the processing of a CSS is high risk

To determine whether the processing of a CSS is high risk, an assessment for each type of processing carried out at the workplace must be completed. However, if there is more than one type of processing at the workplace occurring simultaneously, this may increase the likelihood that there will be a risk to the health of persons at the workplace. In this instance, the assessment may cover all types of processing of a CSS, and it should be consider in the assessment whether this will increase the risk to the health of persons at the workplace.

For example, different workers may be undertaking different types of processing in the same shift. When considered individually each type of processing might not be assessed as high risk with regard to the below considerations. However, the combined exposure to RCS from multiple processes may be reasonably likely to result in a risk to the health of a person at the workplace, making the overall assessment as high risk.

There are a number of factors that a PCBU must have regard to when determining whether a CSP is high risk:

1. the specific processing that will be undertaken
2. the form or forms of crystalline silica present in the CSS
3. the proportion of crystalline silica present in the CSS, determine as a weight/weight (w/w) concentration
4. the hazards associated with the work, including the likely frequency and duration that a person will be exposed to RCS
5. whether the airborne concentration of RCS that is present at the workplace is reasonably likely to exceed half the workplace exposure standard (WES)
6. any relevant air and health monitoring previously undertaken at the workplace, and
7. any previous incidents, illnesses or diseases associated with exposure to RCS at the workplace.

There is no one factor that can determine the outcome of an assessment. When assessing whether a CSP is high-risk, PCBUs must consider all the above factors.

The assessment must be recorded in writing and include how the PCBU has considered the above factors, and the reasons why the processing is determined to be high risk or not high risk.

An optional Assessment to determine if the processing of a CSS is high risk template (PDF, 153.1 KB) has been developed to assist PCBUs.

Additional requirements if processing of CSS has been determined to be high risk

Where the processing of CSS has been assessed as high risk, there are additional requirements that must be undertaken before work commences including:

• development of a silica risk control plan
• providing crystalline silica training to any worker that the PCBU reasonably believes may be involved in processing of a CSS that is high risk or be at risk of exposure to RCS
• undertaking air monitoring for RCS in accordance with regulation 50
• providing the air monitoring results to the regulator if the airborne concentration of RCS has exceeded the workplace exposure standards for RCS, and
• providing health monitoring for all workers carrying out processing of a CSS that is high risk in accordance with Division 6 of Part 7.1 of the WHS Regulations.

Silica risk control plan

If it is determined that the processing of a CSS is high risk, PCBUs must complete a silica risk control plan before commencing any processing.

The silica risk control plan must be developed in consultation with workers involved in carrying out processing of a CSS that is high risk and if any, their elected health and safety representatives (HSR). It must also be set out and expressed in a way that is readily accessible and understandable by the persons who use it.

What must a silica risk plan include?

A silica risk control plan must:

1. identify all processing carried out at the workplace that is high risk
2. contain a copy of the information used to assess the risk, including:
   • the specific processing that will be undertaken
   • the form or forms of crystalline silica present in the CSS
   • the proportion of crystalline silica contained in the CSS, determined as a weight/weight (w/w) concentration
   • the hazards associated with the work, including the likely frequency and duration that a worker will be exposed to RCS
   • results of any relevant air and health monitoring previously undertaken at the workplace
   • information regarding previous incidents, illnesses or diseases associated with exposure to RCS at the workplace
   • whether the airborne concentration of RCS present at the workplace is reasonably likely to exceed half the workplace exposure standard, and
   • the reasons why the processing has been assessed as being a high risk,
     1. document what control measures will be used to control the risks and how those measures will be implemented, monitored and reviewed, and
     2. be set out and expressed in a way that is readily accessible and understandable.

If the processing is also high risk construction work, a safe work method statement (SWMS) can be used instead of a silica risk control plan provided the SWMS covers all the required silica risk control plan content.

A silica risk control plan must be reviewed and as necessary revised if relevant control measures are revised under regulation 38 (review of control measures).

PCBUs can use the same silica risk control plan to document multiple types of processing of a CSS, so long as they provide details for each and outline the specific control measures that will be used to manage the risk of respirable crystalline silica (RCS) for each process.

An optional Silica Risk Control Plan template (PDF, 129.3 KB) is available to assist PCBUs to document any processing of CSS that is high risk and the control measures used to manage the risks of exposure to RCS. The template is not mandatory however, if it the template is not used, PCBUs should ensure that they document all the required information and that they do so in a way that is readily accessible and understandable to persons who use it.

More information is available in the Working with crystalline silica substances: Guidance for PCBUs.

Training

The WHS Regulations require PCBUs to provide crystalline silica training to any worker they reasonably believe may be involved in processing of a CSS that is high risk, or be at risk of exposure to RCS because of the processing of a CSS that is high risk at the workplace. [insert footnote: WHS Regulations, 529D]

Crystalline silica training must be nationally accredited training, or another form approved by the regulator and must cover:

• the health risks associated with exposure to RCS, and
• the need for, and proper use of, any risk control measures required by the WHS laws.

Examples of crystalline silica training that are nationally accredited training are listed on training.gov.au (such as training packages, qualifications, units of competency, skill sets or courses). National accredited training identified includes:

• 10830NAT – Course in Crystalline silica Exposure Prevention
• NAT10830001 – Prevent crystalline silica exposure
• CPCSIL3001 – Work with products and material containing crystalline silica
• CPCSIL4001 – Supervise and manage work with products and materials generating respirable crystalline silica.

PCBUs must ensure a record of crystalline silica training undertaken by workers is kept while the worker is carrying out the processing of a CSS that is high risk and for 5 years after the day the worker ceases working for the business or undertaking.

If the processing of CSS is not high risk, PCBUs must still ensure they are meeting other duties under the WHS laws to provide appropriate information, instruction, training or supervision to workers who may be exposed to RCS at the workplace.

Monitoring

For each processing of a CSS that is high risk at the workplace, a PCBU must:

• undertake air monitoring for respirable crystalline silica in accordance with regulation 50, and
• provide health monitoring for all workers carrying out the processing of a CSS that is high risk in accordance with Division 6 of Part 7.1 of the WHS Regulations.

In addition, PCBUs must provide air monitoring results to the regulator if the airborne concentration of RCS has exceeded the workplace exposure standards (WES) for RCS.

Air monitoring

Regulation 50 of the WHS Regulations requires a PCBU to undertake air monitoring to determine the airborne concentration of a substance or mixture which has a workplace exposure standard (WES) if:

• they are uncertain on reasonable grounds whether or not the airborne concentration of RCS at the workplace exceeds the WES for RCS, or
• monitoring is necessary to determine whether there is a risk to health from RCS at the workplace.

This means that, in addition to any air monitoring necessary to identify whether the processing of a CSS is high risk, PCBUs may also need to undertake additional air monitoring to meet the obligations of regulation 50.

Air monitoring to determine a worker’s exposure involves measuring the level of RCS in the breathing zone of workers using a personal sampler during their usual shift activities, including routine breaks.

The WHS Regulations require PCBUs to keep the results of air monitoring for 30 years. PCBUs must also ensure that the records are readily accessible to people at the workplace who may be exposed to RCS. Any previous air monitoring results in relation to processing of a CSS that is high risk must also be taken into consideration as part of the assessment to determine if the processing of a CSS is high risk, if the air monitoring was relevant and was conducted prior to undertaking the assessment.

Reporting airborne concentration of RCS above the WES

If air monitoring for RCS has been undertaken for processing of a CSS that is high risk and the results show the airborne concentration of RCS has exceeded the WES for RCS, the PCBU must report the results to the WHS regulator.

The results must be reported even if workers are wearing appropriate and correctly fitted respiratory protective equipment (RPE), which provides protection from exposure to RCS.

The results must be reported to the regulator as soon as reasonably practicable and no more than 14 days from the date that the air monitoring result was provided to the PCBU.

The air monitoring results must be reported to the WHS regulator in a form approved by the WHS regulator.

Health monitoring

Division 6 of Part 7.1 of the WHS Regulations requires a PCBU to provide health monitoring to any worker carrying out ongoing work at a workplace using, handling, generating or storing hazardous chemicals and there is a significant risk to the worker's health because of exposure to a hazardous chemical.

This means that where there is significant risk to a worker's health arising from ongoing exposure to RCS, whilst undertaking processing of a CSS that is high risk, the worker must be provided with health monitoring.

Depending on the circumstances, health monitoring may not only be required for workers who are directly generating RCS by regularly undertaking processing of a CSS that is high riskbut also for workers who may regularly be in the vicinity of RCS or in contact with RCS in other ways such as through cleaning work areas or equipment.

Health monitoring must be carried out or supervised by a medical practitioner with experience in health monitoring. Health monitoring for RCS includes workers being screened with specialised equipment. Depending on the worker’s past exposures and medical history, some doctors may recommend carrying out further tests with a specialist to detect early-stage silicosis.

Under WHS laws, the minimum requirements for health monitoring for crystalline silica through exposure to RCS are:

• collection of demographic, medical and occupational history
• records of personal exposure
• standardised respiratory questionnaire
• standardised respiratory function tests, for example, FEV1 (forced expiratory volume in one second), FVC (forced vital capacity) and FEV1/FVC, and
• chest X-ray full posterior-anterior (PA) view.

The medical practitioner doing the workers’ health monitoring will provide the PCBU with a health monitoring report relating to each worker. The report must be kept for at least 30 years and the worker must receive a copy of the report.

PCBUs must provide the health monitoring report to the WHS regulator if the medical practitioner doing your monitoring:

• informs the PCBU that a worker may have contracted a disease, injury, or illness as a result of carrying out work using, handling, generating, or storing silica, or
• recommends that the PCBU take remedial measures (such as stopping a worker from continuing to perform particular work or implementing additional exposure controls).

The Health Monitoring Report form (PDF, 126.3 KB) must be completed and submitted to Comcare with a copy of the health monitoring report to:

• email notify@comcare.gov.au
• fax 1300 305 906.

Further information is available in the Working with crystalline silica substances: Guidance for PCBUs.

What duty holders need to do

PCBU duties

Persons conducting a business or undertaking (PCBUs) have the primary duty of care for the health and safety of their workers and others at the workplace.

A PCBU must ensure, so far as is reasonably practicable, the health and safety or workers at work and ensure that the health and safety of other people is not put at risk from the work carried out by the business or undertaking.

This duty requires the PCBU to manage risks by eliminating health and safety risks so far as reasonably practicable, and if it is not reasonably practicable to eliminate the risks, by minimising those risks so far as is reasonably practicable.

When discussing health and safety matters with workers, PCBUs should take a consultative approach to allow workers a reasonable opportunity to express views before any decision is made. A PCBU also has a range of more specific obligations to manage various health and safety risks, which are set out in the WHS Regulations.

Officer duties

Officers, such as company directors, must exercise due diligence to ensure the PCBU complies with the WHS Act and Regulations. This includes taking reasonable steps to ensure the PCBU has and uses appropriate resources and processes to eliminate or minimise the risks of working with CSS.

Worker duties

Workers have a duty to take reasonable care for their own health and safety and to take reasonable care that their actions or omissions do not adversely affect the health and safety of other people.

Workers must also:

• comply, as far as that are reasonably able, with any reasonable WHS instructions from the PCBU,
• cooperate with any reasonable policy or procedure relating to WHS that the PCBU puts in place
• wear any personal protective equipment as instructed by the PCBU and participate in health monitoring. If the worker refuses, the PCBU may take action to meet its duties under work health and safety laws – including removing the worker from the source of exposure.

Choosing control measures

Under the model WHS Regulations, PCBUs have specific duties to manage the risks to health and safety when using, handling, generating and storing hazardous chemicals, including silica.

PCBUs also have a duty to ensure the workplace exposure standard for crystalline silica is not exceeded and to provide health monitoring to workers.

Managing risks and worker exposures to silica can be achieved by selecting and implementing measures using the hierarchy of controls:

• substitution, such as choosing a benchtop product that does not contain crystalline silica
• isolation of the hazard – using principles of safe work design to designate areas for tasks that generate dust and appropriate worker positioning during these tasks, using enclosures and automation to conduct dust generating tasks
• engineering controls that minimise the risk of exposure to generated dust, for example, local exhaust ventilation, water suppression (wet cutting) or using tools with dust collection attachments
• administrative controls, including good housekeeping policies, shift rotations and modifying cutting sequences
• personal protective equipment including appropriate respiratory protective equipment (generally a minimum of a P2 efficiency half face respirator) and work clothing that does not collect dust.

More than one control will normally be required to adequately protect workers and must be used when processing engineered stone.