Silica

Silica is a very common substance usually found mixed with other materials. The most common form of crystalline silica is quartz found in sand and sandstone. Other forms include cristobalite and tridymite. Crystalline silica dust can occur in quarrying, tunnelling, monumental and architectural masonry, construction processes including maintenance and demolition. One of the most hazardous areas is in sandblasting and therefore efforts should be made to specify a non-siliceous blasting compound or indeed water when such processes are necessary.