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Respirable Crystalline Silica

Respirable Crystalline Silica

In many industries it is now common to find the high-energy operations that can generate respirable crystalline silica. Wherever you find materials such as sand, concrete, brick, block, stone and mortar combined with cutting, sawing, grinding, drilling or crushing there is risk for exposure to respirable crystalline silica. Crystalline silica is also a component used to make certain products: glass, pottery, ceramics, bricks, concrete and artificial stone. Adding to the challenge of controlling exposure, is that respirable crystalline silica is generally at least 100 times smaller than ordinary sand.


Founded in 1984, IEA is an environmental consulting firm with offices in Minnesota providing services throughout the United States.

Our health and safety specialists provide support and services to:

  • Evaluate employee exposures to crystalline silica
  • Compare exposure monitoring results to the current OSHA Action Level and PEL
  • Assist with training and documentation
  • Provide guidance to reduce employee exposure

To learn more about respirable crystalline silica and the requirements of the OSHA standard, contact IEA. Call us toll–free at 800.233.9513.

Scope of Industries Affected

  • Construction
  • Glass manufacturing
  • Pottery products
  • Structural clay products
  • Concrete & ready mix products
  • Foundries
  • Dental laboratories
  • Paintings and coatings
  • Jewelry production
  • Refractory & Furnace operations
  • Landscaping
  • Stone products
  • Abrasive blasting operations
  • Railroads
  • Hydraulic fracturing - gas & oil
  • Asphalt products


OSHA limits exposure to respirable crystalline silica to 50 micrograms per cubic meter of air (µg/m3) over an eight-hour day with an action level of 25 µg/m3 over an eight-hour day.


Construction industry

June 23, 2017 — Employers are required to comply with all obligations of the standard, except methods of sample analysis.

June 23, 2018 — Employers are required to comply with all obligations of the standard, including methods of sample analysis.

All operations in general industry and maritime.

June 23, 2018 — Employers are required to comply with all obligations of the standard including offering medical surveillance to employees exposed above the PEL for 30+ days a year.

June 23, 2020 — Employers are required to also offer medical surveillance to employees who will be exposed at or above the action level for 30+ days a year.

Hydraulic fracturing for the oil & gas industry

June 23, 2018 — Requirements are the same as “All operations in general industry and maritime.”

June 23, 2018 — For this three-year period, employers can continue to have employees wear respirators to 
- June 23, 2021 comply with the PEL.

June 23, 2021 — Engineering controls must be implemented to limit exposures to the new PEL.

Contact IEA to learn how we can help you comply with the requirements of the OSHA Crystalline Silica standard. Call us toll–free at 800.233.9513.


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