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A Simple Guide to Crystalline Silica

Whilst crystalline silica has been known as a dangerous substance for years now, it is receiving increasing attention with tighter regulatory controls. Raising the awareness of its risk and understanding more about it is the first step in ensuring that exposures are minimal. 

In our guide we provide more knowledge on the subject, answering what it is, along with other common questions we frequently get asked.

What is crystalline silica?

Crystalline silica is a basic constituent of sand, stone, soil and other minerals which are frequently used in building materials such as concrete, bricks and tiles found on construction sites. 

When in the form of quartz, it is found at varying proportions in aggregate, mortar, concrete, brick, stone such as granite, shale, sandstone and manufactured stone products. 

Is crystalline silica dangerous?

Yes, it can be extremely dangerous. Crystalline silica can form a dust fine enough to penetrate deep into the lungs during the process of cutting, sanding, drilling or grinding. 

These fine particles are termed as respirable particles. Respirable crystalline silica is one of the most common occupational exposure risks throughout the world and high exposures are typically associated with the mining, quarrying, tunnelling and construction industries. 

The respirable crystalline silica is harmful when particles penetrate into the unciliated airways and has been associated with adverse health outcomes such as lung cancer, silicosis, kidney disease and emphysema. These diseases can be fatal within 5 to 10 years and can impact the lives of people as young as 20 or 30 years of age.

What are the legislative requirements - WHS Regulation?

SafeWork NSW has recently (1 July 2020) reduced the workplace exposure standard (WES) for crystalline silica to 0.05 mg/m3 for an eight-hour time-weighted average (TWA). 

The 8-hour TWA must be taken into consideration as many work sites typically work extended shifts resulting in a requirement to adjust the WES accordingly (ultimately lowering the exposure standard for relevant workers). 

In addition to the reduced crystalline silica WES, SafeWork NSW have also provided recommendations prohibiting the uncontrolled cutting and grinding of materials containing crystalline silica. 

There are also now specific WHS Regulation changes that considers cutting of manufactured stoned (like kitchen benchtops) as high-risk work. 

Workplaces must not allow workers to cut (also includes grind, drill or polish) manufactured stone containing crystalline silica with a powertool unless:

  • Each worker who may inhale the dust must be provided with appropriate respiratory protective equipment that complies with AS/NZS 1716–2012, Respiratory protective devices; and 

  • At least one of the following controls aimed at reducing exposures to dust is implemented, used and maintained:

    • A water delivery system supplying a continuous feed of water over the area being cut;

    • The utilisation of an appropriate on-tool dust extraction system; and/or

    • Local exhaust ventilation to capture the dust produced transporting the dust to a safe emission point, or to a filter or scrubber.

Monitoring exposure of crystalline silica

Workplaces must evaluate hazardous chemicals that pose a serious risk to the health of workers by ensuring that they are not exposed to airborne concentrations of a substance exceeding the workplace exposure standard and if there is any uncertainty, air monitoring must be conducted.

Like asbestosis, mesothelioma, pleural plaques and all other diseases with asbestos, silicosis is now a notifiable disease that goes onto a silicosis register. 

Person Conducting a Business or Undertaking (PCBU) must provide health monitoring for workers if they carry out ongoing work using, handling, generating or storing crystalline silica, and there is a significant risk to the worker’s health because of exposure.

TOP TIPS TO PREVENT EXPOSURE OF CRYSTALLINE SILICA

Eliminate or Substitute the Risk

Where possible, workplaces should aim to eliminate the hazard. This can be achieved by changing the products used (for example, eliminating the use of silica containing products used during work processes) or eliminating processes that generate hazards (for example, purchasing pre-cast silica containing products to prevent the requirement for cutting or grinding products). 

Isolate the Hazard

If elimination is not reasonably practical, workplaces must implement controls aimed at isolating dust generating processes from other workers. This can be achieved through designing physical barriers to create enclosures to contain dust during work processes.

Engineering Controls 

It is imperative workplaces implement engineering controls to minimise the risks associated with exposure to respirable crystalline silica. Wet methods of control such as the continuous supply of water during cutting used in conjunction with a combination of local exhaust ventilation systems; via on-tool dust extraction systems or systems designed to capture dust at the source, reduce dust exposure of workers.

Administrative Controls 

Providing workers with appropriate information, including the development of safe work procedures, training and supervision is important to ensure higher levels of control remain effective and that workers understand the risks associated with the tasks.

Personal Protective Equipment

Workplaces have an obligation to provide workers with appropriate personal protective equipment (PPE). where there is a risk of exposure to respirable crystalline silica, workers must be provided with respiratory protective equipment (RPE) that complies with AS/NZS 1716–2012, Respiratory protective devices and include a testing and training program to correctly fit, instruct on the use and ensure regular maintenance.

How can EDP help?

EDP can provide your business with the following services with the aim of minimising the risks associated with silica in the workplace:  

  • Provide Silica awareness training for workers to inform them of the hazards associated with their work and educate them in the use of correct control measures;
  • Review current workplace practices and controls and provide guidance on achieving legislative compliance;  
  • Validate the effectiveness of workplace controls, aimed at minimising exposures to respirable crystalline silica, by designing and conducting air monitoring programs; and 
  • Assist in the development and review of workplace risk assessments and procedures.

You can get your own copy of our information sheet below