Regulation register: silica and engineered stone
What the law requires now, what is proposed, and when each piece took effect. California has moved in three steps: an emergency standard (2023), a permanent standard (2024) and the STOP Act (2025); a fourth, a ban, is in rulemaking.
At a glance
How to read the verification labels
- Verified: primary source
- Checked by this project against a court record, statute, agency publication or journal index.
- Verified: secondary source
- Checked against a major news organisation, professional body or university publication.
- Reported by an interested party
- Rests on a law-firm release, trade press or legal-marketing site. Treat figures as claims until independently confirmed.
- Unverified
- Listed for completeness; not yet checked against any source by this project.
Tier numbers next to sources (T1 to T4) follow the source hierarchy in the methodology: T1 primary records and agencies, T2 major news and professional bodies, T3 interested parties, T4 discovery-only.
California
Cal/OSHA emergency temporary standard on respirable crystalline silica (amendments to Title 8 CCR section 5204)
Verified: secondary source
Targeted 'high-exposure trigger tasks' (cutting, grinding, polishing, clean-up) on artificial stone and natural stone over 10% silica, tightening controls, respirator use and reporting.
- Body
- Occupational Safety and Health Standards Board / Cal/OSHA
- Type
- emergency regulation
- Status
- Superseded by the permanent standard
- Key dates
- 14 December 2023: Standards Board approves the ETS
- 29 December 2023: ETS effective, for one year
- Requirements
- Applies to high-exposure trigger tasks on stone over 10% crystalline silica
- Enhanced controls and respiratory protection
- Reporting of silicosis cases
- Sources
- AIHAT2Littler MendelsonT3
- Last checked
- 12 September 2026
Cal/OSHA permanent respirable crystalline silica standard (Title 8 CCR section 5204, as amended)
Verified: secondary source
Continues and strengthens the 2023 emergency standard: exposure assessments reassessed every six months, engineering and work-practice controls, medical surveillance with medical removal protection, written exposure control plans, and 24-hour reporting of confirmed silicosis or cancer cases.
- Body
- Occupational Safety and Health Standards Board
- Type
- regulation
- Status
- In force
- Key dates
- 19 December 2024: Standards Board votes unanimously to make the emergency provisions permanent
- 2025: Effective after Office of Administrative Law approval; exact date not verified by this project
- Requirements
- Exposure assessment every six months
- Medical removal protection up to six months
- Written exposure control plan reviewed annually
- 24-hour employer reporting of confirmed RCS-related silicosis or cancer
- Sources
- Littler MendelsonT3AIHAT2
- Last checked
- 12 September 2026
SB 20, Silicosis Training, Outreach, and Prevention (STOP) Act (Chapter 734, Statutes of 2025)
Verified: primary source
Amends Labor Code sections 6302 and 6432 and adds Chapter 2.2 (sections 6359.1 to 6359.5). Prohibits dry methods for high-exposure trigger tasks on artificial stone, requires annual employer attestation of training, classifies artificial-stone silicosis as a serious injury or illness, requires CDPH to report cases to Cal/OSHA within three business days and Cal/OSHA to investigate within three business days, and requires CDPH worker outreach.
- Body
- California Legislature
- Type
- statute
- Status
- In force from 1 January 2026
- Key dates
- December 2024: Introduced by Senator Caroline Menjivar
- 13 October 2025: Signed and chaptered (Chapter 734)
- 1 January 2026: Operative
- 1 July 2026: First annual training attestation due to Cal/OSHA
- Requirements
- Wet methods only for high-exposure trigger tasks on artificial stone
- Annual employer attestation from 1 July 2026
- Silicosis treated as a serious injury or illness
- CDPH-to-Cal/OSHA case referral within three business days
- Sources
- California Legislative InformationT1Office of Senator Caroline MenjivarT1
- Last checked
- 12 September 2026
Silicosis made a reportable disease in California
Verified: primary source
Health care providers must report identified or suspected silicosis to the local health department within seven calendar days. CDPH shares cases with Cal/OSHA under SB 20.
- Body
- California Department of Public Health
- Type
- regulation
- Status
- In force
- Key dates
- June 2025: Reportability effective
- 17 November 2025: CDPH CAHAN advisory to providers
- Requirements
- Provider reporting within 7 calendar days
- Sources
- California Department of Public HealthT1
- Last checked
- 12 September 2026
Petition 609: proposed prohibition on fabrication and installation of artificial stone containing more than 1% crystalline silica
Verified: secondary source
If adopted, California would become the first US state to prohibit fabrication and installation of high-silica engineered stone. An emergency temporary standard would last one year while permanent rules are developed. No text had been adopted as of this project's last check.
- Body
- Occupational Safety and Health Standards Board
- Type
- petition
- Status
- Granted in part; rulemaking initiated
- Key dates
- December 2025: Petition filed by the Western Occupational and Environmental Medicine Association (WOEMA), backed by more than 600 health professionals
- 10 April 2026: Cal/OSHA evaluation memorandum
- 21 May 2026: Board votes unanimously (three members present) to grant the petition in part, directs Cal/OSHA to prepare an emergency finding for expedited rulemaking and to convene advisory committees
- Sources
- Public Health WatchT2WorkCompWire (reprinting DIR release 2026-45)T2California Department of Industrial RelationsT1Occupational Safety and Health Standards BoardT1
- Last checked
- 12 September 2026
United States (federal)
OSHA respirable crystalline silica standard (29 CFR 1910.1053 and 1926.1153)
Verified: primary source
Sets a permissible exposure limit of 50 micrograms per cubic metre (8-hour TWA) and an action level of 25, with exposure assessment, engineering controls, respiratory protection, medical surveillance and training requirements.
- Body
- Occupational Safety and Health Administration
- Type
- regulation
- Status
- In force
- Key dates
- 25 March 2016: Final rule published, 81 FR 16286
- 23 June 2016: Rule effective
- 23 June 2018: General industry compliance date (per rule text; not separately re-verified)
- Requirements
- PEL 50 ug/m3 8-hour TWA
- Action level 25 ug/m3
- Written exposure control plan
- Medical surveillance for exposed workers
- Sources
- Federal Register / OSHAT1
- Last checked
- 12 September 2026
OSHA/NIOSH Hazard Alert: Worker Exposure to Silica during Countertop Manufacturing, Finishing and Installation
Verified: primary source
Non-binding federal guidance warning employers that countertop fabrication can expose workers to silica above the PEL and describing controls.
- Body
- OSHA and NIOSH
- Type
- guidance
- Status
- Current (2026 edition)
- Key dates
- 2015: Original alert issued, DHHS (NIOSH) Publication 2015-106
- 26 February 2026: Jointly updated alert issued, NIOSH 2026-101 / OSHA HA-3768-2026
- Sources
- NIOSH / OSHAT1NIOSH / OSHAT1
- Last checked
- 12 September 2026
H.R. 5437, Protection of Lawful Commerce in Stone Slab Products Act (119th Congress)
Verified: secondary source
Would bar civil actions against manufacturers and sellers of stone slab products for injuries from respirable silica arising from third-party fabrication, and, as reported, would apply to pending cases. Sixteen cosponsors listed as of the last check. Opposed by public-health and labour witnesses; supported by the engineered-stone industry.
- Body
- U.S. House of Representatives
- Type
- bill
- Status
- Ordered reported by the House Judiciary Committee; not passed
- Key dates
- 17 September 2025: Introduced by Rep. Tom McClintock (R-CA); referred to the Judiciary Committee
- 14 January 2026: Judiciary subcommittee hearing, 'Between a Rock and a Hard Place: Protecting the American Stone Slab Industry'; witnesses included former OSHA head David Michaels
- 3 June 2026: Committee markup; ordered reported as amended, 16 to 7
- Sources
- Congress.govT1Quiver QuantitativeT4U.S. House of Representatives (docs.house.gov)T1KFF Health NewsT2
- Last checked
- 12 September 2026
International
Australian prohibition on engineered stone benchtops, panels and slabs
Verified: primary source
World-first ban on the manufacture, supply, processing and installation of engineered stone benchtops, panels and slabs containing at least 1% crystalline silica.
- Body
- WHS ministers / Safe Work Australia
- Type
- regulation
- Status
- In force
- Key dates
- 13 December 2023: WHS ministers unanimously agree to ban
- 1 July 2024: Prohibition commences in all jurisdictions
- 31 December 2024: End of transitional exemption for contracts signed on or before 31 December 2023
- Sources
- Safe Work AustraliaT1
- Last checked
- 12 September 2026
Notes on verification
- California statute text was read on the Legislature's own site (leginfo). The Cal/OSHA standards and Standards Board actions are described from AIHA, a law-firm bulletin and a reprint of the Department of Industrial Relations release, because
dir.ca.govrefuses connections from outside the United States. The regulation text itself (Title 8 CCR section 5204) has not been read by this project; a reader in the United States can check it directly. - The federal rule was checked against the Federal Register API. H.R. 5437's actions were read from a mirror of congress.gov, which blocks automated access; the House hearing document was read on docs.house.gov.
- Nothing here is legal advice. Employers and workers should rely on the official text and on Cal/OSHA's own guidance.