Respirable Crystalline Silica (RSC) and Occupational Health Issues

Control Measures 

Research shows significant reductions in RCS exposure with water-fed tools (71%) and local exhaust ventilation (69%).

• A 2024 ban on resin-bonded engineered stone with over 1% crystalline silica was implemented.
• Health monitoring is legally required where RCS exposure presents a significant risk, including occupational history, respiratory function testing, and radiological assessment.
• Control measures include wet methods to suppress dust, local exhaust ventilation, positive-pressure cabins, and worker segregation from high-concentration areas.
• Effective control measures include engineering controls, administrative controls, and PPE, with historical reductions in silicosis due to medical monitoring and exposure reduction.

Engineering Controls

• Use sharp cutting tools that minimise the generation of large quantities of fine dust.
• Use wet processes to prevent dust generation, particularly when the process involves freshly cut quartz surfaces.
• Use water (or water with additive) suppression to prevent dust spread.
• Minimise the fall distance of dust generating materials (e.g. ensure ore passes are not emptied below the brow point and crusher chutes are kept full).
• Use water curtains and rubber curtains to prevent dust release, particularly at conveyor transfer points and chute draw points.
• Use suitable ventilation, either dilution or preferably local extraction, to control dust spread and dust release.
• Ensure suppressed dust is captured by scrubbing or filtering so it cannot be re-entrained in workplace air.

Administrative Controls

• Apply good housekeeping practices to prevent dust build-up (especially important inside vehicle dust-proof cabins).
• Use a vacuum cleaner with an appropriate filter to clean up dust spills
• Provide training in the health effects of RCS dust, its sources, and its control, and communicate the results of airborne monitoring and the assessed risk of exposure at the workplace.

Linked Legislative And Standards

Safe Work Australia  (2024c) Model WHS Regulations mandate eliminating or minimising health and safety risks, following the hierarchy of risk control.

• Mandate that PCBUs ensure airborne concentrations of substances do not exceed exposure standards, with the WES for RCS set at 0.05 mg/m3, except in Victoria at 0.025 mg/m3.
• From May 2023, WorkSafe ACT requires all PCBU in the ACT to ensure all workers who fall under the list of specified occupations and those who may be exposed to silica dust as part of their work complete the Nationally accredited course 10830NAT – Course in Crystalline Silica Exposure Prevention to continue to work on a construction site in the ACT.

Engineered stone ban

• As of July 1, 2024, there is a total ban on the manufacture, supply, processing, and installation of engineered stone across Australia.
  • There is a transition period for engineered stone contracts entered into before December 31, 2023
  • SafeWork NSW Online notification form requires that PCBUs must annually notify them about any legacy engineered stone that has been installed.

AIOH Recommendations

• Health risk assessments should be conducted by competent professionals, ensuring long-term average exposure remains below 0.05 mg/m3 to minimise health risks.
• Regular health monitoring, including occupational history, respiratory function testing, and radiological assessment, is essential for worker safety.

Current Issues to Resolve

The current issue is that many workplaces may not comply with current Workplace Exposure Standards (WES) due to a lack of enforcement or awareness, especially in construction and manufacturing.

Codes of Practice

• SafeWork NSW COP – Managing the risks of respirable crystalline silica from engineered stone in the workplace
• SafeWork QLD COP – Managing respirable crystalline silica dust exposure in the construction and manufacturing of construction elements
• SafeWork Australia Working with crystalline silica substances: Guidance for PCBUs
• WorkSafe ACT – Crystalline Silica Dust Guidance Note
• WorkSafe ACT COP – Managing the Risks of Airborne Crystalline Silica (Silica Dust) in the Workplace
• WorkSafe WA COP –  Managing the risks of respirable crystalline silica from engineered stone in the workplace
• Safe Work SA – Respirable crystalline silica in construction and demolition work
• NT WorkSafe – Guide to working with crystalline silica and crystalline silica containing products