California’s so-called quartz ban is not a ban on quartz. It’s a workplace safety rule that prohibits dry cutting, grinding, polishing, and other dust-generating methods when fabrication shops work on engineered stone and certain natural stones. The regulation lives in California Code of Regulations, Title 8, Section 5204, and Senate Bill 20 adds statutory backing plus training and reporting duties. Engineered stone countertops are still sold and installed in California, and a countertop already in your kitchen is not a health risk.
What the Rule Actually Prohibits
The core prohibition targets “high-exposure trigger tasks”: cutting, grinding, drilling, polishing, chiseling, or breaking covered stone. Employers cannot use any dry method for these tasks. Senate Bill 20 writes that ban into statute.
A few common shop habits are also off-limits, whether or not air monitoring shows low silica levels:
- Using compressed air to blow dust off surfaces, clothing, equipment, or filters.
- Dry sweeping, shoveling, or otherwise disturbing dry silica dust or debris.
- Walking or driving equipment through accumulated dry dust.
- Rotating employees through high-exposure tasks to spread out exposure.
These prohibitions apply across the board. Even if measured silica stays below the permissible exposure limit, the dry-method ban still governs every high-exposure trigger task.1Department of Industrial Relations. California Code of Regulations Title 8 5204 – Occupational Exposures to Respirable Crystalline Silica
Which Countertop Materials Are Covered
The rule uses silica content to draw the line, and the threshold depends on whether the stone is manufactured or natural.
Artificial stone covers reconstituted, synthetic, composite, engineered, or manufactured products, including the “quartz” material made by binding crushed stone with resin. The trigger is very low: any artificial stone containing more than 0.1% crystalline silica by weight falls under the high-exposure trigger task rules.1Department of Industrial Relations. California Code of Regulations Title 8 5204 – Occupational Exposures to Respirable Crystalline Silica Because most engineered stone runs 90% or more crystalline silica, practically every quartz slab on the market is covered.2Centers for Disease Control and Prevention. Silica Hazards from Engineered Stone Countertops
Natural stone gets a higher threshold. Granite and similar stones are covered when they contain more than 10% crystalline silica by weight. Marble, which usually sits under 5%, generally falls below the line and is not subject to the high-exposure trigger task rules.1Department of Industrial Relations. California Code of Regulations Title 8 5204 – Occupational Exposures to Respirable Crystalline Silica
Why California Wrote the Rule
Cutting or grinding engineered stone releases respirable crystalline silica. Inhaling that dust causes silicosis, an incurable lung disease that scars the lungs and can require transplant or become fatal. The disease is old in mining and construction, but the rise of engineered stone in the 2000s produced a new wave of cases in relatively young fabrication workers.
California has tracked engineered stone silicosis since 2019. By early 2024 the state had confirmed 296 cases tied to engineered stone work, with at least 15 deaths and 60 transplant referrals.3US House of Representatives. Silicosis Surveillance in California, 2019-2024 – Tracking an Epidemic By early 2026, the California Department of Public Health reported over 500 confirmed cases and at least 29 deaths. Many of the workers affected are in their 30s and 40s.
The federal permissible exposure limit is 50 micrograms of respirable silica per cubic meter as an 8-hour average, with an action level of 25 micrograms.4Occupational Safety and Health Administration. Silica, Crystalline California’s rule goes further by writing specific prohibitions and engineering controls into the stone-fabrication context rather than relying on exposure monitoring alone.
How Compliant Shops Have to Work Now
With dry methods off the table, fabricators have to use wet methods for every high-exposure trigger task. The regulation recognizes three:
- A constant, continuous flow of water directly on the tool-to-stone contact area, meeting or exceeding the tool manufacturer’s flow specifications when water is integrated into the tool. Recycled water must be filtered to remove silica before reuse.
- Submerging the work piece underwater during fabrication.
- Water jet cutting with high-pressure water.
Whichever method a shop chooses, dust must stay below the action level at all times.1Department of Industrial Relations. California Code of Regulations Title 8 5204 – Occupational Exposures to Respirable Crystalline Silica
Wet methods alone are not enough. Employers must also provide respiratory protection for high-exposure trigger tasks, with a full-face, tight-fitting powered air-purifying respirator (PAPR) as the default. Less restrictive options are allowed only if six-month air monitoring shows exposures stay below the action level.1Department of Industrial Relations. California Code of Regulations Title 8 5204 – Occupational Exposures to Respirable Crystalline Silica
Every employer with workers performing high-exposure trigger tasks must maintain a written exposure control plan, conduct air monitoring at least annually (more often when readings are elevated), and provide free medical exams to any worker doing this work at least 30 days a year. Exams include a baseline within 30 days of assignment and periodic exams at least every three years, with chest X-rays and pulmonary function testing performed by a physician experienced in occupational lung disease.1Department of Industrial Relations. California Code of Regulations Title 8 5204 – Occupational Exposures to Respirable Crystalline Silica
Penalties and Shutdowns
Cal/OSHA enforces the rule through inspections, citations, and fines. Serious violations carry penalties of up to $25,000 per instance. Willful or repeated violations can reach $162,851 per violation.5California Department of Industrial Relations. Cal/OSHA Increases Civil Penalty Amounts for 2025
When inspectors find an imminent hazard, Cal/OSHA can issue an Order Prohibiting Use, sometimes called a yellow tag. That shuts down the specific machine, tool, or work area until the employer fixes the hazard and the Division confirms it. The order is narrow in scope, but losing a primary cutting station can stop production.6California Department of Industrial Relations. California Department of Industrial Relations Policy and Procedures Manual P and PC C-8 – Order Prohibiting Use
Senate Bill 20 also classifies silicosis from artificial stone as a serious injury or illness under the Labor Code, which shortens reporting timelines and sharpens the state’s response when a worker is diagnosed.7California State Senate. Governor Newsom Signs SB 20 The Silicosis Training, Outreach and Prevention STOP Act
Key Dates
The rules arrived in stages. The Cal/OSHA Standards Board approved an Emergency Temporary Standard on December 14, 2023, and it took effect December 29, 2023.8California Department of Industrial Relations. Division of Occupational Safety and Health – Emergency Temporary Silica Standard – What Employers Need to Know The Standards Board voted unanimously on December 19, 2024, to make the rules permanent. The Office of Administrative Law filed the permanent standard on February 5, 2025, and it took effect the same day.1Department of Industrial Relations. California Code of Regulations Title 8 5204 – Occupational Exposures to Respirable Crystalline Silica
Governor Newsom signed Senate Bill 20 on October 14, 2025. Starting July 1, 2026, employers whose workers perform high-exposure trigger tasks must file an annual written attestation with Cal/OSHA confirming that every such worker has received required training. The law also directs the California Department of Public Health to conduct outreach on silicosis prevention and diagnosis.9California Legislative Information. SB 20 – Senate Bill 20
What This Means If You’re Buying or Already Own Countertops
Engineered stone is still legal to sell and install in California. The rule targets how fabricators work, not what consumers can buy. Shops that meet the wet-method, respirator, and monitoring requirements can keep producing quartz countertops.
Compliance has costs, though, and you may feel them. Some smaller fabricators cannot afford the required equipment upgrades and have closed or stopped working with engineered stone. Lead times can be longer, and quartz prices can run higher than they did before the regulation. Some buyers have moved to natural marble, porcelain, or solid-surface materials that fall below the high-exposure trigger task thresholds.
If you already have engineered stone in your home, there is nothing to do. Silicosis comes from inhaling fine dust generated during cutting and grinding. A finished, installed countertop sitting in your kitchen does not release silica dust in normal use.