Silica and Workplace Exposure

Australia is in the middle of a silica crisis, and many workplaces still don’t realise how exposed they are. Respirable crystalline silica (RCS) continues to cause preventable, irreversible disease across construction, mining, tunnelling, quarrying and manufacturing. But unlike hazardous substances that workers actively choose to handle, silica is everywhere: in concrete, stone, brick, tile, mortar and the earth itself. That’s what makes it so dangerous. People don’t know they’re at risk because the dust they can’t see is the dust that causes the most harm.

The scale of the problem has prompted a major regulatory response. Since May 2024, silicosis has become a nationally notifiable disease through the newly established National Occupational Respiratory Disease Registry, with mandatory reporting requirements for diagnosed cases. Landmark legal decisions involving tunnelling workers have set national precedents. And the transition from Workplace Exposure Standards (WES) to enforceable Workplace Exposure Limits (WEL) in December 2026 signals that regulators expect organisations to treat silica risk management as non-negotiable.

What Is Silica & Where Is It Found?

Silica is a naturally occurring mineral found in rock, sand and soil. In workplace settings, the primary concern is crystalline silica, a form that becomes hazardous when materials containing it are disturbed during work activities.

A critical distinction must be made between visible dust and respirable crystalline silica. Larger dust particles may be seen and tend to settle quickly. Respirable crystalline silica particles are extremely small and can be inhaled deep into the lungs, where they may cause long-term damage. These particles are usually invisible and may remain airborne for extended periods.
Crystalline silica is present in materials including concrete and cement, bricks and tiles, stone and mortar, grout and engineered stone, and quarry products.

As a result, silica exposure occurs across a wide range of industries: construction, mining, quarrying, tunnelling, manufacturing and stone fabrication. This breadth is part of the problem. Where other hazardous substances require procurement and are clearly labelled, silica is simply part of the material being worked on. Many workers generating RCS don’t recognise that the exposure is occurring.

How Silica Exposure Occurs in the Workplace

Silica exposure occurs when work activities generate fine dust containing respirable crystalline silica. Tasks such as cutting concrete, grinding stone, drilling masonry, crushing materials and blasting rock can release high concentrations of silica dust into the air.

Exposure may occur indoors or outdoors. Enclosed spaces, dry cutting techniques and inadequate ventilation increase airborne concentrations, but outdoor work does not eliminate risk, particularly where controls are not properly implemented or maintained.

Tunnelling environments deserve specific attention. Recent legal cases have shown that tunnelling can produce persistent clouds of respirable crystalline silica, especially when ventilation and dust suppression systems are inadequate. The landmark case of Craig Bennett (NSWDDT 2025/5), a tunnelling worker diagnosed with silicosis, has set a national precedent and is relevant to all work that breaks into the earth’s crust and generates RCS.

Exposure can be acute or long-term. Acute exposure involves short-term inhalation of very high concentrations of silica dust, while long-term exposure involves repeated lower-level inhalation over time. Even short-duration tasks may generate hazardous exposures if dust is not effectively controlled.

Health Effects of Silica Exposure

Short-term silica dust exposure may cause irritation of the eyes, nose and throat, coughing and breathlessness. These symptoms are often mild initially and may not prompt medical attention. That is precisely why they are so dangerous.

Long-term exposure to respirable crystalline silica can result in serious and irreversible disease. Silicosis — progressive scarring of lung tissue that restricts breathing — is the most well-known condition. But silica exposure is also associated with lung cancer, chronic obstructive pulmonary disease, kidney disease and autoimmune conditions such as scleroderma.

Many silica-related diseases have long latency periods, meaning symptoms may not appear until years after exposure has ceased. There is no safe level of respirable crystalline silica exposure. That is why regulators emphasise exposure prevention rather than reliance on exposure limits alone.

Australia is now experiencing a major resurgence in silica-related disease, with a dramatic rise in cases among engineered stone benchtop workers and recent landmark legal decisions involving tunnellers. These events have intensified regulatory scrutiny and led to the introduction of mandatory national reporting of silicosis through the National Occupational Respiratory Disease Registry.

Acute vs. Long-Term Silica Exposure

Acute silica exposure occurs when workers inhale very high concentrations of silica dust over a short period. This may lead to acute silicosis, a rare but severe condition that can develop within months and progress rapidly.

Long-term exposure involves repeated inhalation of lower concentrations over months or years. This pattern is most commonly associated with chronic silicosis and other long-term respiratory conditions.

How much silica exposure is dangerous? Risk depends on cumulative dose, duration, particle size and individual susceptibility. This uncertainty underpins the regulatory expectation that exposure be reduced as far as reasonably practicable, not just to the limit, but below it where possible.

Understanding Silica Risk Work & WHS Obligations

Under Australian work health and safety laws, respirable crystalline silica is recognised as a high-risk hazardous substance. Workplace exposure standards are transitioning to enforceable workplace exposure limits, defining the maximum average airborne concentration permitted over an eight-hour workday.

Employers and PCBUs must identify silica risk work, conduct exposure assessments and implement effective controls. These obligations apply even when monitoring results fall below published limits.

The transition from Workplace Exposure Standards to Workplace Exposure Limits — taking effect in December 2026 — reinforces that these values are enforceable, not aspirational. This has increased expectations for proactive silica risk management, documentation and review of control measures.

Since May 2024, silicosis has also become a nationally reportable occupational respiratory disease. Under the National Occupational Respiratory Disease Registry, clinicians must report diagnosed silicosis cases. The registry supports prevention and early intervention, strengthening surveillance in high-risk industries and forming a key component of WHS compliance frameworks across Australia.

Preventing & Controlling Silica Exposure

Preventing silica exposure relies on applying the hierarchy of controls. Elimination and substitution are the most effective measures, such as avoiding silica-containing materials or using alternative construction methods where feasible.

Engineering controls play a critical role where elimination is not possible. These include wet cutting techniques, on-tool dust extraction, local exhaust ventilation and dust containment systems designed to capture dust at the source.

Administrative controls include safe work procedures, silica exposure control plans and worker training. Personal protective equipment, such as respirators, may be required but should never be relied upon as the sole control measure.

Monitoring & Testing Silica Exposure

Monitoring silica exposure is a key component of effective risk management, but it’s important to understand what you’re measuring and why.

Air monitoring measures the concentration of respirable crystalline silica in the workplace and helps assess whether controls are effective. This is environmental monitoring. It answers the question: “What’s in the air?”

Health surveillance is different. It monitors workers’ health over time where exposure cannot be fully eliminated. It answers a separate question: “What’s happening to the person?”

One cannot replace the other when exposure pathways, cumulative risk or individual susceptibility exist. Occupational hygienists typically conduct silica exposure assessments, including personal air sampling. Health surveillance supports early identification of adverse health effects and informs fitness-for-work decisions.

Under the national registry framework introduced in 2024, clinicians must report diagnosed silicosis cases, strengthening early detection and enabling improved surveillance in high-risk industries.

Role of Occupational & Environmental Physicians (OEPs)

OEPs play a critical role in the management of silica workplace exposure, and that role has become more important as the scale of Australia’s silica problem has come into focus.

In industries now known to be high-risk — tunnelling, engineered stone fabrication, construction, mining and quarrying — OEPs are at the front line of early identification. Australia’s largest modern outbreaks of silica-related disease have occurred in these sectors, and OEPs are central to detecting cases before they become irreversible.

What does this look like in practice? OEPs interpret exposure data alongside clinical information. They assess individual risk, advise on health surveillance requirements, guide fitness-for-work decisions and collaborate with occupational hygienists to ensure monitoring programs are fit for purpose.

Health surveillance for silica-exposed workers may include baseline and periodic health assessments, lung function testing and review of exposure history. Early identification allows timely intervention and supports safe work continuation. But only if the right clinicians are involved from the start.

Silica Health Services From Phoenix Occupational Medicine

Are you confident your silica health surveillance program is catching problems early? Do you know which medicals your workers actually need, and whether your program meets the current regulatory requirements?

Phoenix Occupational Medicine provides specialist-led silica health services, including:

Silica Baseline & Periodic Health Surveillance — ongoing monitoring of workers exposed to RCS, including lung function testing, respiratory questionnaires and clinical review by an OEP
RSHQ Mineral Mines & Quarries Medicals — compliant health assessments for workers in Queensland’s mining and quarrying sectors
RHSQ Queensland Coal Mine Workers’ Health Scheme Medicals — medicals conducted under the Coal Mine Workers’ Health Scheme as regulated by Resources Safety & Health Queensland
Interpretation of air monitoring results — collaboration with occupational hygienists to translate environmental data into clinical action and fitness-for-work decisions

Our OEPs work with employers and hygienists to design health surveillance that is fit for purpose, not just a compliance checkbox, but a program that actually identifies risk and supports your workers.

Need to set up a silica health surveillance program, or not sure whether your current one meets the latest requirements? Get in touch with our team.

Key Takeaways

Australia is experiencing a resurgence in silica-related disease. Silicosis is now a nationally notifiable condition with mandatory reporting.

Respirable crystalline silica exposure causes serious and irreversible disease, and there is no safe level of exposure.

The transition from WES to WEL (December 2026) means enforceable limits and higher compliance expectations.

Tunnelling, engineered stone, construction, mining and quarrying are high-risk industries where early identification is critical.

Health surveillance and air monitoring serve different purposes. Both are needed.

Phoenix Occupational Medicine offers specialist silica health surveillance, RSHQ and RHSQ medicals, and air monitoring interpretation led by OEPs.

Information provided is general only and should not be construed as legal or medical advice. We recommend that readers seek advice for their specific circumstances.