California’s Division of Occupational Safety and Health (Cal/OSHA) has convened a silica advisory committee to evaluate whether the state should follow Australia’s precedent and ban engineered stone products containing crystalline silica. For the U.S. surface materials industry, this is the regulatory development to watch in 2026 — a California ban would be the first in North America and would send shockwaves through the entire supply chain.

What the Advisory Committee Is Examining

The Cal/OSHA silica advisory committee’s scope includes:

1. Feasibility of an Engineered Stone Ban

Drawing directly from the Australian experience, the committee is evaluating whether a ban is technically and economically feasible for California’s market. Key questions: Are silica-free alternatives available in sufficient volume and variety? What are the costs of transition for fabrication businesses? What’s the enforcement burden on Cal/OSHA?

2. Alternative Regulatory Approaches

The committee is also considering alternatives to an outright ban, including:

• Mandatory wet-cutting only for all stone products
• Stricter permissible exposure limits (PEL) for crystalline silica, potentially below the federal OSHA standard of 50 µg/m³
• Licensing and certification requirements for stone fabrication shops
• Mandatory health monitoring and reporting for stone workers

3. California’s STOP Act Implementation

The Stone Worker Occupational Protection (STOP) Act, which took effect in 2025, already requires stone fabrication businesses to register with Cal/OSHA, implement dust controls, and provide health monitoring. The advisory committee is assessing whether the STOP Act’s requirements are sufficient or whether a ban is the logical next step.

What We Know So Far

While no final decision has been made, several signals point toward significant action:

• Political alignment: California’s legislature has demonstrated willingness to regulate engineered stone — the STOP Act passed with bipartisan support
• Union pressure: Labor organisations representing stone workers are actively campaigning for a ban, citing the Australian precedent
• Industry positioning: Major fabricators and distributors in California are already diversifying their product lines toward silica-free alternatives, anticipating regulatory change
• Medical evidence: California’s public health department has documented silicosis cases among engineered stone workers in the state, strengthening the case for intervention

What This Means for Your Business

If you operate in California or sell into the California market:

1. Don’t wait for a final rule. The STOP Act is already in force. If you haven’t registered with Cal/OSHA and implemented compliance measures, start now.
2. Evaluate your product mix. If your business depends heavily on engineered stone fabrication, begin developing silica-free capabilities. The companies that transition early will capture market share when (not if) regulations tighten.
3. Build your documentation system. California enforcement is increasingly focused on documentation — SDS, health monitoring records, dust control logs. If you can’t produce these on demand, you’re exposed.
4. Watch the committee timeline. A recommendation is expected in late 2026. Subscribe to our newsletter for updates as they develop.

For California compliance resources, see our free checklist covering Cal/OSHA STOP Act requirements and silica-free product alternatives.