Silica is silicon dioxide. It is naturally occurring and found in many 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).
Exposure to silica dust can result in:
- illness and disease
- for example sarcoidosis, breathing problems, chronic bronchitis, emphysema, lung cancer, progressive massive fibrosis and silicosis, and
- for example eye irritation and eye damage.
There are three types of silicosis—acute, chronic and accelerated. Silicosis and progressive massive fibrosis are irreversible and often fatal. Symptoms of these diseases may not appear for many years after exposure. Workers may be diagnosed with these diseases and not present with any symptoms, even at the point of initial diagnosis, which is why prevention and health monitoring are critical.
As the duty holder, you will need to implement a combination of different control measures to eliminate or minimise generating silica dust at your workplace. This includes when working with naturally occurring silica (for example in mining or tunnelling) or working with products containing high amounts of silica (such as engineered stone).
If you rely solely on one control measure, such as PPE, there may be a significant risk to your worker’s health and you may be breaching WHS laws. It has been shown that solely relying on PPE does not adequately protect your workers.
This guide is only intended to provide guidance about how you can control the risks of silica dust. It does not cover every hazard that may be present at your workplace. You must be careful to make sure that when you are controlling silica dust that you are not introducing other hazards or not fulfilling your WHS duties for other hazards.
You can manage risks of exposure to silica dust by selecting and implementing measures using the hierarchy of controls.
Figure 1 The hierarchy of control measures