Emergency Rulemaking to Prohibit the Fabrication of Engineered Stone Countertops Containing More than One Percent Crystalline SilicaAdvisory Meeting

The Division of Occupational Safety and Health (Cal/OSHA) will convene an advisory meeting to solicit stakeholder input on a proposed emergency regulation to prohibit the fabrication of engineered stone countertops and similar products with more than one percent crystalline silica (as requested by Petition 609) to protect engineered stone fabrication workers from silicosis. Silicosis is a permanently debilitating and fatal disease.

Due to the current engineered stone silicosis crisis in California, Petition File No. 609 requested that California prohibit the fabrication and installation of engineered stone containing more than one percent crystalline silica. The Occupational Safety and Health Standards Board granted the petition in part and requested that Cal/OSHA initiate emergency rulemaking to amend the crystalline silica standard (section 5204) and to simultaneously convene advisory committee meetings to undertake a review of the silica standard and potential associated regulations.

Any interested person may attend and participate in the advisory meeting either in person or through the above video conference link. Individuals may provide oral comments during the meeting and may also submit written comments before or after the meeting to the Cal/OSHA Research and Standards Branch at RS@dir.ca.gov.

Meeting Documents

• Questions for the Advisory Meeting prior to adopting an emergency regulation
• Agenda

Background Information

• Petition File No. 609
• CDPH Engineered Stone Silicosis Surveillance Dashboard
• Annotated bibliography (English)
  • Bibliografía anotada (español)
• OEHHA Chronic Recommended Exposure Limit for Respirable Crystalline Silica of 3.0 micrograms per cubic meter, 2005.
• Fazio J., et al (2025). A review of silicosis and other silica-related diseases in the engineered stone countertop processing industry. J Occup Med Toxicol. 20:9. https://doi.org/10.1186/s12995-025-00455-8
• Flattery, J., et al. (2025). Silicosis surveillance in California, 2019–2024: Tracking an epidemic. American Journal of Public Health, 115(11), 1913–1921. https://doi.org/10.2105/AJPH.2025.308225
• Heinzerling A. et al (2025). Deadly Countertops: An Urgent Need to Eliminate Silicosis among Engineered Stone Workers. Am J Respir Crit Care Med, 211(4):557-559.  DOI: 10.1164/rccm.202410-2008VP .
• Lateef S., et al (2026). Silicosis Epidemic among Engineered Stone Countertop Workers: Pictorial Review. RadioGraphics. Volume 46, Number 3. https://doi.org/10.1148/rg.250079
• León-Jiménez, A. et al(2025). High metabolic activity in positron emission tomography and systemic inflammation occurring years after exposure cessation in engineered stone silicosis. Sci Rep 15, 25364. https://doi.org/10.1038/s41598-025-10562-5
• Pavan, C. et al (2026). The combined role of silanols and oxidative stress in determining engineered stone dust toxicity. ACS Organic & Inorganic Au, 6(1). https://doi.org/10.1021/acsorginorgau.5c00089
• Gandhi S. Et al (2026). American Thoracic Society Assembly on Environmental, Occupational and Population Health, Silicosis in the Artificial Stone Countertop Industry: An Official American Thoracic Society Workshop Report. Annals of the American Thoracic Society, 2026;, aaoag176, https://doi.org/10.1093/annalsats/aaoag176