Crystalline Silica: Job Activities Posing Risk

Job Activities Posing Risk

A construction worker in dust while operating a dowel drill on a concrete runway.

A construction worker in dust while operating a dowel drill on a concrete runway. Photo by NIOSH.

There are a number of industries where workers can have jobs at risk for exposure to crystalline silica dust.  Examples include construction, mining, oil and gas extraction, stone countertop, foundries and other manufacturing settings, and even dentistry.

Job activities within these industries such as cutting, quarrying, drilling, and abrasive blasting can put a worker at risk for exposure if proper engineering controls and respiratory protection are not implemented.

Sources of Exposure

Crystalline silica is found in soil, sand, concrete, mortar, granite, other minerals, and artificial stone. The most common form of crystalline silica is quartz; however, it can also occur in the form of cristobalite and tridymite. Exposure to cristobalite typically occurs in foundries where the intense heat of molten metal causes cristobalite to be formed in clay molds. When workers cut, drill, chip, sand, or grind materials that contain crystalline silica, hazardous levels of respirable crystalline silica dust can be released into the air that workers breathe.

Exposures Occur During the Following Activities
  • Manufacturing of glass, pottery, ceramics, bricks, concrete, and artificial stone
  • Abrasive blasting
  • Foundry work
  • Hydraulic fracturing
  • Stonecutting
  • Rock drilling
  • Quarry work
  • Tunneling

Resources for Silica in Industry

Page last reviewed: December 18, 2020