Silica dust is a significant health hazard for workers – very small particles of silica dust cannot be seen under normal lighting or with the naked eye and stay airborne for long periods of time. When airborne, workers can inhale the small silica dust particles deep into their lungs where they can lead to a range of respiratory diseases, including silicosis. Safe Work Australia has produced the following information on managing the health and safety risks associated with working silica containing products:
https://www.safeworkaustralia.gov.au/doc/working-silica-and-silica-containing-products