California makes enhanced silica protections permanent
California's enhanced general-industry silica protections became permanent on February 5, 2025. The amendments added protections for specified high-exposure tasks, including monitoring and respiratory protection, while retaining the existing 50 µg/m³ permissible exposure limit.
Task exceptions and respirator alternatives need site-specific review. The separate September 2026 artificial-stone discussion draft has not established an enacted ban.
- Legal status
- Permanent regulation effective
- Source check
- Sep 17, 2026
- Topic
- Respirable crystalline silica
- Technical review
- Jiaxi · 2026-09-23
What changed
Previous requirement
Emergency protections in force from December 29, 2023 with 2024 readoptions.
New requirement or current position
Permanent high-exposure task controls, at least annual monitoring for trigger tasks, respiratory protections and surveillance; existing 50 microgram/m3 PEL retained.
Who it affects
- Stone fabrication
- Artificial stone
- Natural stone processing
- General industry
Dates and milestones
Commencement and compliance dates can differ. Read the conditions beside each date, including any stay or local adoption requirement.
- Announcement or publication
- Feb 5, 2025
- Recorded effective date
- Feb 5, 2025
Covered general-industry silica operations
Selected exposure values
These values need the scope, limit type and averaging period shown below. A proposed or advisory value is not a binding limit.
Respirable crystalline silica
50 µg/m³| Averaging period | 8-hour TWA |
|---|---|
| Limit type | PEL retained |
| Scope | California section 5204 |
What this could mean for your IH program
Advisory interpretation: Apply trigger-task duties even where an exposure reading is below the PEL. The amendment is more than a numerical-limit change.
Confirm applicability with a qualified practitioner before changing your program.
Questions and qualifications
- This record does not encode every task exception or respirator alternative.
Source evidence
- Title 8 section 5204: Respirable Crystalline Silica
California DIR / Cal/OSHA · (b)(8), (c), (d)(3), (f)(2), (h), (j); History item 6
Permanent text effective February 5, 2025. High-exposure trigger tasks include artificial stone above 0.1% silica and other stone above 10%; annual minimum sampling, wet controls and added respiratory/medical safeguards.
- Silica Non-Emergency Regulation
California OSHSB · Status table
Permanent regulation filed and effective February 5, 2025; rulemaking history distinguishes 2024 proposal and emergency readoptions.
Managing your IH program
Explore how LEAP IH supports industrial hygiene data management and risk assessment.
Explore LEAP IHSee a missing update or a correction? Contact APT with this page and the official source.