Silica and Worker Health

Key points

  • Millions of U.S. workers are exposed to respirable crystalline silica (RCS) in a variety of industries.
  • Silica dust can be released in the air when working.
  • Workers exposed to RCS can develop serious lung disease.
Close up of stone cutting with dust.


Silica dust is made up of small particles that can become airborne during work activities with materials that contain silica. Particles that are small enough to be inhaled deep into the lungs are called respirable.

Crystalline silica is typically found in:

  • Soil
  • Sand
  • Concrete
  • Mortar
  • Granite and other minerals
  • 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 intense heat of molten metal causes cristobalite to form in clay molds. Hazardous levels of respirable dust can be released into the air when working with materials that contain silica.

Silicosis, an irreversible but preventable lung disease, is caused by inhalation of RCS. Work exposures to RCS also cause other serious diseases, including lung cancer.


Worker cutting stone countertop using wet method.
Worker cutting stone countertop using wet method.

Exposures can occur during the following activities:

  • Glass, pottery, ceramics, bricks, concrete, and artificial stone manufacturing
  • Abrasive blasting
  • Foundry work
  • Hydraulic fracturing
  • Stonecutting
  • Rock drilling
  • Quarry work
  • Tunneling

There are various industries where workers can have jobs at risk for RCS exposure. Examples include:

  • Construction
  • Mining
  • Oil and gas extraction
  • Stone countertop fabrication
  • Foundries and other manufacturing settings
  • Dentistry


Key publications and posts

Communication products

Searchable database

NIOSHTIC-2 is a searchable bibliographic database of occupational safety and health publications, documents, grant reports, and other communication products supported in whole or in part by NIOSH. Search "silica" for more publications.