Silica Dust Regulations in Australian Mining

Respirable crystalline silica (RCS) is one of the most significant occupational health hazards in Australian mining. Found in virtually all rock, sand, clay and gravel, silica dust is generated by drilling, blasting, hauling, crushing, screening and dozens of other routine mining activities. The health consequences of prolonged exposure are severe and irreversible: silicosis, progressive massive fibrosis, chronic obstructive pulmonary disease, lung cancer and kidney disease.

Australia’s regulatory response has been evolving rapidly. Queensland and New South Wales—home to the country’s largest mining sectors—have both tightened their silica dust frameworks in recent years, with stricter exposure limits, expanded monitoring obligations, mandatory health surveillance, and an unambiguous regulatory preference for engineering controls over respiratory protection. Nationally, Safe Work Australia’s September 2024 amendments introduced Chapter 8A into the model WHS Regulations, creating dedicated provisions for crystalline silica management across all industries.

Most significantly, Safe Work Australia has proposed a further 50% reduction in the national Workplace Exposure Standard (WES) for RCS—from the current 0.05 mg/m³ to 0.025 mg/m³. From 1 December 2026, the current standard is also being reclassified as a Workplace Exposure Limit (WEL), carrying strengthened legal weight. Regulators are already signalling that mine operators should be designing their dust control systems to meet the anticipated lower benchmark.

For mine operators across Queensland and New South Wales, the message is clear: the regulatory trajectory points only one way, and the time to invest in engineering-based dust controls is now.

Current Exposure Standards: QLD, NSW and the National Framework

Both Queensland and New South Wales apply a workplace exposure standard of 0.05 mg/m³ (8-hour TWA) for respirable crystalline silica. This limit has been in effect since 1 September 2020, when both states adopted the lowered national standard. Both states also apply a respirable coal dust limit of 1.5 mg/m³—significantly stricter than the national standard of 3.0 mg/m³—along with a diesel particulate matter (DPM) limit of 0.1 mg/m³.

Where shifts exceed the standard eight hours, exposure limits must be adjusted downward. Queensland requires that the dose of respirable dust over a longer shift does not exceed the equivalent eight-hour dose. In practice, this means a 12-hour shift at a Queensland coal mine has an effective adjusted OEL for RCS of approximately 0.047 mg/m³.

Note: Both QLD and NSW apply the 1.5 mg/m³ coal dust limit—half the national standard. The proposed national RCS reduction to 0.025 mg/m³ would again halve the current limit across all jurisdictions.

Queensland: Legislative Framework and Obligations

Queensland’s mining dust management is governed by two principal Acts: the Coal Mining Safety and Health Act 1999 (for coal mines) and the Mining and Quarrying Safety and Health Act 1999 (for metalliferous mines and quarries). Each Act is supported by a corresponding 2017 Regulation that prescribes detailed requirements for exposure monitoring, dust control, health surveillance and reporting.

Mine operators must develop a Safety and Health Management System (SHMS) that explicitly addresses dust as a principal hazard. The SHMS must include provisions for monitoring and recording dust and silica concentrations in workers’ breathing zones, ensuring exposures do not exceed the OEL of 0.05 mg/m³ for RCS and 1.5 mg/m³ for respirable coal dust, implementing engineering controls as the primary means of dust reduction, providing health surveillance (including chest X-rays and lung function testing) at the employer’s expense, and retaining monitoring records for 30 years where the hazard has a cumulative or delayed effect.

Recognised Standard 14 (RS14) is the key technical document for Queensland coal mines. It sets out the methodology, frequency and reporting requirements for monitoring respirable dust, crystalline silica and inhalable dust. Complementing this is QGL02, the guideline for management of respirable dust in mineral mines and quarries, which provides a practical framework covering qualitative risk assessment, the hierarchy of controls, similar exposure group (SEG) sampling strategies, and periodic monitoring schedules.

Exceedances must be reported to the Mines Inspectorate, and the Site Senior Executive (SSE) is personally obligated to report any diagnosed silica-related diseases—including silicosis, progressive massive fibrosis, COPD or lung cancer—in current or former workers as soon as practicable.

New South Wales: The Strongest Regime in Australia

NSW has consistently positioned itself as having the most stringent mining dust framework in the country. The Work Health and Safety (Mines and Petroleum Sites) Act 2013 and its 2022 Regulation apply to all coal mines, metalliferous mines, quarries and petroleum sites in the state. The 2022 Regulation introduced several important reforms: it expanded mandatory airborne dust sampling to non-coal mines where RCS has been identified as a hazard, changed the minimum sampling requirement from “at least five hours” to “minimum 80% of a shift,” required all air samples to be tested for silica content, and introduced additional reporting requirements for exceedances of airborne contaminants.

The NSW Resources Regulator uses a trigger action response plan (TARP) to escalate its response to dust exposure exceedance events. The TARP considers the number, frequency and concentration of exceedances to determine the regulatory response level, which can range from advisory notices through to formal enforcement action.

September 2024: Chapter 8A Crystalline Silica Amendments

From 1 September 2024, new crystalline silica management provisions (Chapter 8A of the WHS Regulation 2017) apply across all NSW workplaces, including mines. The amendments require all persons conducting a business or undertaking (PCBUs) to control the processing of any crystalline silica substance (CSS)—defined as any material containing at least 1% crystalline silica by weight. Processing includes activities such as cutting, drilling, grinding, crushing, blasting, screening and tunnelling through silica-bearing material.

Where processing is assessed as high-risk—or where the PCBU cannot determine whether it is high-risk—operators must prepare a silica risk control plan, provide accredited crystalline silica training to workers, and undertake air monitoring with results reported to the Regulator if concentrations exceed the WES. The NSW Resources Regulator considers compliance with the existing mine-specific legislation (PHMPs, exposure monitoring under Section 89, health surveillance) to be substantially equivalent to Chapter 8A requirements, with specific exceptions around respiratory protection standards.

October 2025: NSW Silica Worker Register

From 1 October 2025, NSW employers must notify workers undertaking high-risk silica processing activities to the Silica Worker Register within 28 days of work starting. This digital register enables SafeWork NSW and the Dust Diseases Authority to identify workers who require health monitoring and detect early changes in respiratory health across the workforce. Workers regulated under the Coal Industry Act 2001 are exempt from this requirement.

The Proposed National WES Reduction: Preparing for 0.025 mg/m³

Safe Work Australia has proposed halving the national WES for RCS from 0.05 mg/m³ to 0.025 mg/m³. In October 2024, WHS ministers requested further impact analysis before confirming adoption, but the trajectory is unambiguous. The health-based review originally recommended a limit as low as 0.02 mg/m³, but measurability concerns with current Australian sampling and analysis equipment led to the interim adoption of 0.05 mg/m³ in 2019, with a commitment to further review.

From 1 December 2026, the current WES for RCS will also be reclassified as a Workplace Exposure Limit (WEL) under the national framework, carrying strengthened legal obligations. Regulators across both Queensland and New South Wales are already signalling that mine operators should be designing and procuring dust control systems capable of meeting the lower 0.025 mg/m³ benchmark.

For mine operators, this proposed reduction has practical implications. Operations that are currently compliant at 0.05 mg/m³ but running close to the limit may find themselves in exceedance territory if the standard halves. The time to evaluate and upgrade dust suppression systems is before the new limit takes effect—not after.

Why Engineering Controls Are the Mandated Priority

Both Queensland and NSW legislation—along with the national model WHS Regulations and the new Chapter 8A provisions—require dust management to follow the hierarchy of controls. Engineering controls must be the primary mechanism for reducing worker exposure, with administrative controls and respiratory protective equipment (RPE) used only as supplementary measures.

The NSW Resources Regulator’s October 2024 position paper on preventing worker exposure to RCS makes this explicit: RPE can only be relied upon once all higher-order control measures are in place, and must comply with AS/NZS 1716:2012 and AS/NZS 1715:2009, including fit-testing requirements. Workers must be clean-shaven when using tight-fitting respiratory protection, including powered air-purifying respirators.

This regulatory preference for engineering controls aligns with the evidence: controls that eliminate or reduce a hazard at source protect every worker in the area, continuously, without reliance on individual behaviour or PPE compliance. For surface mining operations, the most significant engineering control opportunities lie across several key areas.

Haul Roads and Material Transport

Haul roads are consistently among the largest sources of airborne dust on surface mine sites. Every loaded truck pass generates a plume of particulate matter that includes respirable crystalline silica, particularly in quartz-rich geological environments common across Australian mining regions. Traditional water-only spraying offers temporary suppression, but evaporation in Australia’s arid and semi-arid conditions frequently demands retreatment multiple times per shift—consuming vast volumes of water for limited suppression duration.

Polymer-based dust suppressants bind fine particles into a cohesive surface layer that resists disturbance from traffic and wind. Unlike water alone, polymer treatments extend effective suppression from hours to days or weeks, substantially reducing application frequency and total water consumption. When combined with soil stabilisation products that improve the structural integrity of the road surface, operators achieve a dual benefit: lower dust emissions and a stronger, more durable haul road that reduces tyre wear, fuel consumption and maintenance costs.

Drilling, Blasting and Processing

Drill rigs equipped with on-board dust collectors capture a significant proportion of respirable dust at the point of generation. Wet drilling systems that inject water or specialised dust control agents into the borehole suppress dust before it reaches the breathing zone. Post-blast, rapid application of chemical suppressants to the muck pile limits secondary dust generation during loading.

At crushing and screening plants, enclosure of transfer points, exhaust ventilation, and wet suppression systems (including fog cannons and misting arrays) are standard engineering approaches. The addition of surfactant-enhanced suppressant solutions improves particle capture by reducing water droplet surface tension, enabling finer mist particles to bind more effectively with airborne dust.

Automated Dosing and Real-Time Monitoring

The monitoring and documentation demands of both QLD and NSW regulations—periodic exposure sampling, SEG analysis, qualitative risk assessments, exceedance reporting and 30-year record retention—create a significant compliance burden. Automated SMART dosing systems that meter suppressant delivery based on real-time environmental conditions (traffic volume, wind speed, humidity) help maintain consistent dust control while generating the time-stamped operational data that supports compliance documentation.

Real-time particulate monitors at fixed locations or on mobile equipment provide early warning when concentrations approach the OEL, enabling corrective action before an exceedance event triggers regulatory escalation. This proactive approach aligns with the philosophy underlying both QGL02 and the NSW TARP framework: prevent overexposure rather than respond to it after the fact.

Global Context: How Australia Compares

Australia’s tightening silica standards sit within a broader global trend. In the United States, the Mine Safety and Health Administration (MSHA) published a final rule in April 2024 that lowers the mining PEL for RCS to 50 µg/m³ (0.05 mg/m³)—aligning with Australia’s current standard—and mandates engineering controls as the primary compliance pathway. The MSHA rule also introduces an action level of 25 µg/m³, medical surveillance for metal and nonmetal miners, and explicitly prohibits worker rotation as a compliance strategy.

While MSHA’s rule has been subject to litigation and a rulemaking reconsideration that has delayed US enforcement timelines, the convergence is striking: both Australian and American regulators are independently arriving at the same conclusions about the level of protection miners need, the inadequacy of RPE-dependent strategies, and the central role of engineering controls in achieving sustainable compliance.

ISO 23875, the international standard for air quality control systems in operator enclosures, adds a further layer of alignment. The standard establishes performance requirements for enclosed cab filtration systems and is increasingly referenced by both Australian regulators and MSHA as a benchmark for equipment-based dust control. For multinational mining operators, investment in engineering controls that meet the most stringent global benchmarks—rather than the minimum local requirement—is emerging as both the safest and most cost-effective long-term strategy.

A Practical Compliance Roadmap for Australian Mine Operators

Operators in Queensland and New South Wales can take concrete steps now to strengthen their compliance position—and to prepare for the anticipated reduction to 0.025 mg/m³.

1. Establish a current exposure baseline. If your operation does not already have comprehensive SEG-based exposure data, begin full-shift sampling across all roles where RCS may be present—drillers, blasters, haul truck operators, crusher and screen operators, maintenance crews and laboratory staff. Use sampling methods compliant with AS 2985 (respirable dust) and AS 3640 (inhalable dust) and accredited laboratories for analysis.
2. Map your dust generation points. Identify the locations and activities generating the highest concentrations of airborne dust. Haul roads, crusher feeds, conveyor transfer points, drill benches, stockpile loading zones and ROM pads are typical high-exposure areas. Prioritise these for engineering control investment.
3. Invest in engineering controls that target the source. Evaluate polymer dust suppression on haul roads, enclosed operator cabins with HEPA-grade filtration (to ISO 23875), wet suppression at crushing and screening plants, ventilation systems at transfer points, and automated dosing systems for continuous dust management. Design to the anticipated 0.025 mg/m³ standard—not just the current 0.05 mg/m³ limit.
4. Review your SHMS or PHMP documentation. Ensure your Safety and Health Management System (QLD) or Principal Hazard Management Plan for airborne contaminants (NSW) reflects current best practice, including a silica risk control plan that satisfies Chapter 8A requirements. Document your hierarchy-of-controls approach and the rationale for each control measure.
5. Strengthen health surveillance and monitoring records. Confirm that all exposed workers are enrolled in appropriate health surveillance programmes. In NSW, ensure compliance with the Silica Worker Register notification requirements. Maintain exposure monitoring records for the legally required retention periods—30 years in Queensland where the hazard has cumulative or delayed effects.
6. Track the regulatory trajectory. Assign a compliance lead to monitor Safe Work Australia’s progress on the proposed WES reduction, any further amendments to Chapter 8A, and state-level enforcement guidance from the Queensland Mines Inspectorate and the NSW Resources Regulator. When the standard changes, you should already be compliant.

The Bottom Line

Australia’s silica dust regulations represent some of the most stringent mining health protections in the world, and they are still tightening. Queensland and New South Wales have led the way with exposure standards, monitoring requirements and enforcement frameworks that prioritise engineering controls and place clear obligations on mine operators to protect their workforce.

The proposed national reduction to 0.025 mg/m³—combined with the reclassification of the WES as a WEL from December 2026, expanded Chapter 8A provisions, and the NSW Silica Worker Register—signals a regulatory environment that is becoming more demanding, not less. Mine operators who treat this period as an opportunity to invest in source-based dust control, strengthen their monitoring infrastructure, and build robust compliance documentation will be positioned to meet whatever standard takes effect next.

The health risks of silica dust exposure do not wait for regulations to catch up. Neither should your dust control strategy.

Sources and References

Business Queensland: Queensland Mines Legislation and Dust Management

Business Queensland: Exposure Limits for Dust

Business Queensland: Standards, Codes of Practice and Guidance on Dust

Queensland Resources: QGL02: Guideline for Management of Respirable Dust in Mineral Mines and Quarries (PDF)

RSHQ: Recognised Standard 14: Monitoring Respirable Dust in Coal Mines (PDF)

NSW Resources Regulator: Airborne Contaminants and Dust

NSW Resources Regulator: Position Paper – Regulatory Approach to Crystalline Silica (April 2025)

SafeWork NSW: Crystalline Silica Amendment Regulation 2024 (Chapter 8A)

SafeWork NSW: Working Safely with Crystalline Silica and Engineered Stone

Safe Work Australia: Workplace Exposure Standard for Respirable Crystalline Silica

Safe Work Australia: Research into a Lower WES and STEL for Respirable Crystalline Silica

Coal Services: Standing Dust Committee – Respirable Crystalline Silica

MSHA: Final Rule – Lowering Miners’ Exposure to Respirable Crystalline Silica (Federal Register) (for global context)

Komatsu: Understanding the New ISO 23875 Air Quality Standards for Mining