Silica, Crystalline

Silica, Crystalline Menu Workers' Rights
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General Industry and Maritime

OSHA's Respirable Crystalline Silica standard for general industry and maritime requires employers to limit worker exposures to respirable crystalline silica and to take other steps to protect workers.

Among other things, the standard requires employers to:

  • Assess employee exposures to silica if it may be at or above an action level of 25 µg/m3 (micrograms of silica per cubic meter of air), averaged over an 8-hour day;
  • Protect workers from respirable crystalline silica exposures above the permissible exposure limit (PEL) of 50 µg/m3, averaged over an 8-hour day;
  • Limit workers' access to areas where they could be exposed above the PEL;
  • Use dust controls to protect workers from silica exposures above the PEL;
  • Provide respirators to workers when dust controls cannot limit exposures to the PEL;
  • Use housekeeping methods that do not create airborne dust, if feasible;
  • Establish and implement a written exposure control plan that identifies tasks that involve exposure and methods used to protect workers;
  • Offer medical exams - including chest X-rays and lung function tests - every three years for workers exposed at or above the action level for 30 or more days per year;
  • Train workers on work operations that result in silica exposure and ways to limit exposure; and
  • Keep records of exposure measurements, objective data, and medical exams.

General industry and maritime employers must comply with all requirements of the standard by June 23, 2018, except for the following:

Medical surveillance must be offered to employees who will be exposed at or above the action level for 30 or more days a year starting on June 23, 2020. (Medical surveillance must be offered to employees who will be exposed above the PEL for 30 or more days a year starting on June 23, 2018.)

Hydraulic fracturing operations in the oil and gas industry must implement engineering controls to limit exposures to the new PEL by June 23, 2021.

OSHA begins enforcement of the Respirable Crystalline Silica standard for general industry and maritime on June 23, 2018, while offering assistance during the first 30 days of enforcement to employers making good faith efforts to meet the new standard's requirements. See the June 7, 2018 memorandum.

General Industry and Maritime Outreach Materials

Sample Powerpoint for General Industry and Maritime. Provides a customizable Powerpoint for employers and other instructors to tailor their training on how to comply with OSHA's respirable crystalline silica standard for general industry and maritime.

Small Entity Compliance Guide for the Respirable Crystalline Silica Standard for General Industry and Maritime [Español]. Discusses suggested engineering and work practice controls, exposure assessments, respirator use, medical surveillance, written exposure control plans, and other aspects of compliance.

General Industry and Maritime Fact Sheet. Provides a summary covering the requirements of the respirable crystalline silica standard for general industry and maritime.

OSHA Standards, Interpretations, and Directives

General Industry and Maritime Standard (29 CFR 1910)

OSHA Directives

Standard Interpretations

Frequently Asked Questions

State Standards

There are 28 OSHA-approved State Plans, operating state-wide occupational safety and health programs. State Plans are required to have standards and enforcement programs that are at least as effective as OSHA's and may have different or more stringent requirements.

General Industry and Maritime Resources
  • Silica. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic. Provides information about silica as well as links to related publications and references.
  • Natural and Engineered Stone Countertop Manufacturing, Finishing, and Installation.
    • OSHA NIOSH Hazard Alert: Worker Exposure to Silica during Countertop Manufacturing, Finishing and Installation. (2023) [Español](2023). This Hazard Alert discusses ways to protect workers from significant crystalline silica exposure during manufacturing, finishing, and installing natural and manufactured stone countertops. The Hazard Alert follows reports of 46 workers in Spain and 25 workers in Israel who developed silicosis as a result of exposure to crystalline silica in their work manufacturing stone countertops.
    • Severe Silicosis in Engineered Stone Fabrication Workers – California, Colorado, Texas, and Washington, 2017-2019. (2019). U.S. Department of Health and Human Services. Morbidity and Mortality Weekly Report (MMWR). This MMWR describes silicosis, autoimmune disease, and latent tuberculosis infection in stone fabrication workers.
    • Working Safely with Natural and Engineered Stone Products. National Occupational Research Agenda. (2019). This webinar describes the dangers of silica exposure, employer requirements to comply with OSHA’s Respirable Crystalline Silica Rule, and methods employers can use to protect workers. It was hosted by the NORA Respiratory Health Cross-Sector Council, OSHA, the California Department of Public Health’s Occupational Health Branch, CPWR – The Center for Construction Research and Training, and the Natural Stone Institute.
    • Silicosis Risk for Workers. Washington State Department of Labor and Industries. (2019). This Hazard Alert discusses ways to protect workers who saw, grind, sand, finish, or install natural or engineered stone countertops. The Hazard Alert notes stone countertop workers in Washington and California developing silicosis from silica exposures.
    • Silica Exposures Frequently Exceed the Legal Limit in Stone Fabricators. Washington State Department of Labor and Industries. (2019). This report illustrates the findings of silica samples taken during Washington state inspections from 2007-2018, finding many instances of overexposures..
  • OSHA NIOSH Hazard Alert: Worker Exposure to Silica During Hydraulic Fracturing. U.S. Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 2012-166, (2012). This Hazard Alert discusses the health hazards associated with hydraulic fracturing and focuses on worker exposures to silica in the air. It covers the health effects of breathing silica, recommends ways to protect workers, and describes how OSHA and NIOSH can help.
  • OSHA Fact Sheet: Protecting Workers from the Hazards of Abrasive Blasting Materials. OSHA Publication 3697, (2013).
  • "Control of Silica Exposures in Foundries." American Foundry Society (AFS; 2007). Developed by the AFS Safety and Health Committee as a product of an AFS/OSHA Alliance, this manual provides useful technical information for foundries to use in controlling worker exposures to respirable crystalline silica. (Note: The document does not fully reflect the new permissible exposure limit and other requirements established by the OSHA's Respirable Crystalline Silica Standard.)
  • Video: "Don't Let Silica Dust You!" Produced by the Association of Occupational and Environmental Clinics with support from NIOSH, the California Department of Public Health, San Francisco Bay area bricklayers and roofers unions, and other partners, the video describes the use of controls and identifies enablers and barriers for reducing workplace exposure to crystalline silica.
  • OSHA Clinicians page. The page provides information for clinicians to understand important ethical, regulatory, and clinical issues.
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