According to the website silica-safe.org, silica is one of the most common naturally occurring elements on the planet. The mineral compound is found in two forms — crystalline or noncrystalline (also referred to as amorphous). Sand and quartz are common examples of crystalline silica. If undisturbed, materials that contain crystalline silica are not hazardous. Once disturbed, however, they generate small-sized particles that can get in the lungs — “respirable crystalline silica.”
NIOSH field studies show that workers in the oil and gas industry may be exposed to dust with high levels of respirable crystalline silica during hydraulic fracturing or “fracking,” a process used to “stimulate” well production that involves large quantities of silica sand.