Crystalline silica and silicosis

Engineered stone ban

The ban on the manufacture, supply, processing and installation of engineered stone benchtops, panels and slabs is in effect.

Learn more on the engineered stone ban web page.

What is crystalline silica? 

Silica is silicon dioxide, a naturally occurring and widely abundant mineral that forms the major component of most rocks and soils. There are non-crystalline and crystalline forms of silicon dioxide. The most common type of crystalline silica is quartz (CAS 14808-60-7). 

Different types of rock and rock products can contain different amounts of crystalline silica, for example: 

What is silica dust? 

Silica dust or respirable crystalline silica (RCS) is generated in workplace mechanical processes such as crushing, cutting, drilling, grinding, sawing, polishing, quarrying and tunnelling natural stone or man-made products that contain crystalline silica. Because the particles generated are so tiny, RCS can be breathed in and can penetrate deep into the lungs where they can cause irreversible lung damage.

Work activities that may represent a high risk exposure 

Silica is one of the most abundant minerals found in the earth’s crust and is used in many products across a variety of industries and workplaces. Crystalline silica is most dangerous to health when dust is generated, becomes airborne and is then inhaled. 

Examples of work activities that can generate RCS include: 

• using power tools to cut, grind or polish natural and engineered stone countertops 
• excavation, earth moving and drilling plant operations 
• clay and stone processing machine operations 
• paving and surfacing 
• mining, quarrying, mineral ore treating processes
• mechanical screening 
• road construction and tunnelling 
• construction labouring and demolition 
• brick, concrete or stone cutting; especially using dry methods 
• abrasive blasting (blasting agent must not contain greater than 1 per cent of crystalline silica) 
• foundry casting 
• angle grinding, jack hammering and chiselling of concrete or masonry 
• hydraulic fracturing of gas and oil wells
• pottery making 
• crushing, loading, hauling and dumping of rock, and 
• clean-up activities such as sweeping.

What diseases can silica dust cause? 

If a worker is exposed to and breathes in RCS they could develop: 

• 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. It can lead to fibrotic nodules, shortness of breath, and progressive massive fibrosis 
• chronic bronchitis
• emphysema 
• lung cancer 
• kidney damage, or 
• 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.

WHS duties in relation to crystalline silica and RCS

Persons carrying out a business or undertaking (PCBUs) have a primary duty of care for the health and safety of workers and others at the workplace. In addition to this primary duty, PCBUs have specific duties relating to crystalline silica, these include:

• duties that apply to work with any material containing 1% or more crystalline silica (these materials are called crystalline silica substances or CSSs, and they include engineered stone) (please refer to the Working with crystalline silica substances: Guidance for PCBUs),
• duties to manage the risks to health and safety when using, handling, generating and storing hazardous chemicals, including crystalline silica, and
• duties in relation to the engineered stone prohibition (please refer to the Engineered stone prohibition: Guidance for PCBUs).

Health monitoring for workers exposed to crystalline silica 

Under the model WHS Regulations, PCBUs must provide health monitoring for workers if they are carrying out ongoing work using, handling, generating or otherwise exposed to respirable crystalline silica and there is a significant risk to the worker’s health because of exposure. 

The minimum health monitoring requirements for crystalline silica include: 

• collection of demographic, medical and occupational history 
• records of personal exposure 
• standardised respiratory questionnaire 
• standardised respiratory function tests, for example, FEV1, FVC and FEV1/FVC, and 
• chest X-Ray full PA view (baseline and high risk workers only). 

Further information about the duties for health monitoring can be found in:  

• Health monitoring for exposure to hazardous chemicals - Guide for medical practitioners
• Health monitoring – Guide for crystalline silica

Workplace Exposure Standard (WES)

The workplace exposure standard (WES) for RCS is 0.05 mg/m³ (eight-hour time weighted average). A person must not be exposed to RCS above the WES.

PCBUs should keep worker exposure to silica dust as low as reasonably practicable. Air monitoring must be conducted if there is any uncertainty that the WES is being exceeded or to find out if there is a risk to a worker’s health. 

Further information

You can find further information on what you must do to keep your workers safe from the risks of crystalline silica in our Working with crystalline silica substances: Guidance for PCBUs and supporting resources.

For specific information on working with engineered stone products refer to the Engineered stone ban: Guidance for PCBUs