What is processing of a crystalline silica substance?

Processing of a crystalline silica substance involves tasks such as cutting, drilling, grinding or polishing. This work causes very fine particles of crystalline silica dust to be released. This dust is known as respirable crystalline silica, or RCS.

If inhaled, RCS can cause serious health issues depending how much dust a worker breathes in and for how long. In its solid form, crystalline silica is not harmful.