Crystalline silica: Safety basics

What is crystalline silica?

Crystalline silica is a natural mineral. It's found in natural and man-made materials such as engineered stone, granite and sandstone.

Crystalline silica includes substances such as quartz, cristobalite, tridymite or tripoli. It's also in other building materials such as concrete, bricks, tiles and mortar.

How much crystalline silica is present depends on the material. Engineered stone, also known as reconstituted, artificial or manufactured stone, can have very high crystalline silica content, often up to 95%.

Common materials and their typical crystalline silica content include:

• sandstone, 70% to 90%
• granite, 25% to 60%
• ceramic tiles, 5% to 45%
• autoclaved aerated concrete, 20% to 40%
• slate, 20% to 40%
• concrete, less than 30%
• porcelain, 14% to 18%
• brick, 5% to 15%
• marble, less than 5%
• engineered stone, 1% or more crystalline silica, determined as a weight/weight concentration

Engineered stone ban

From 1 July 2024, the manufacture, supply, processing or installation of engineered stone benchtops, panels or slabs is banned in Victoria. The engineered stone ban applies to engineered stone benchtops, panels and slabs. Engineered stone products not in these forms are not banned. There are limited exceptions to the ban where work can be performed on engineered stone benchtops, panels and slabs. This includes:

• removal, repair or modification of installed engineered stone benchtop and panels
• disposal of installed or uninstalled engineered stone benchtops, panels and slabs
• research and analysis, and
• to sample and identify engineered stone

Specific controls are required when permitted engineered stone work involves an engineered stone process. An engineered stone process is also considered high risk crystalline silica work and you must comply with the high risk crystalline silica work obligations.

For more information, see the guidance Working with engineered stone and Frequently asked questions – Engineered stone ban.

Exposure to crystalline silica dust

When you do things like cut, grind, drill or polish products that contain crystalline silica, it releases very fine dust. Some of the dust is so small you may not be able to see it.

Workers in industries like stonemasonry, construction, manufacturing and the extractives industry may be exposed to crystalline silica dust.

More information about exposure to crystalline silica dust is available from Lung Foundation Australia. Lung Foundation Australia is a peak body that funds life-changing research and delivers support services to people living with lung disease or lung cancer.

Health risks

Silica dust can be harmful when it's inhaled into your lungs.

Exposure can lead to deadly diseases, including:

• silicosis
• lung cancer
• kidney disease
• autoimmune disease such as scleroderma
• chronic obstructive pulmonary disease (COPD)

Silicosis occurs when crystalline silica dust scars the lungs. It's a serious and incurable disease, with symptoms including shortness of breath, coughing, fatigue and weight loss. In severe cases, silicosis can require a lung transplant or lead to death.

Workplace exposure standard

Under the Occupational Health and Safety Regulations 2017, employers must ensure employees are not exposed to respirable crystalline silica dust at the workplace at a level above the exposure standard. Safe Work Australia publishes exposure standards for airborne contaminants in the workplace. The exposure standards are in Safe Work guidance, Workplace exposure standards for airborne contaminants.

The exposure standard for respirable crystalline silica dust is 0.05 mg/m3 as a time-weighted average (TWA) airborne concentration over 8 hours.

An 8-hour TWA exposure standard is the average airborne concentration of a particular substance permitted over an 8-hour working day and 5-day working week.

WorkSafe Victoria recommends that employers take a precautionary approach and reduce employees' exposure to below 0.02 mg/m3 as an 8-hour TWA to prevent silicosis and minimise the risk of lung cancer.