Cal/OSHA drafts ban on fabricating high-silica quartz counters after 644 silicosis cases

California workplace regulators have floated an emergency rule that would stop shops from making or cutting the high-silica quartz slabs sold as kitchen and bathroom countertops, a step aimed at an accelerating silicosis outbreak among fabrication workers. The Division of Occupational Safety and Health posted a Sept. 16 discussion draft for a new Title 8 section 5204.1 and related changes to the existing silica standards, with written comments due Sept. 30 at RS@dir.ca.gov.

Under the draft, manufacture or fabrication of "artificial stone" containing more than 1% crystalline silica by weight would be prohibited beginning 60 days after an emergency regulation takes effect. Shops could keep working inventory purchased or already on hand before the effective date, but only for 180 days and only if they stay in full compliance with section 5204, according to the draft text summarized in Cal/OSHA's advisory materials and stakeholder filings.

The California Department of Public Health, in a Sept. 30 letter from Director and State Public Health Officer Erica Pan, M.D., M.P.H., strongly supported adopting the proposal. As of Sept. 16, CDPH had identified 644 silicosis cases among engineered-stone countertop fabrication workers in California, including at least 35 deaths, 75 lung transplants and 53 additional transplant referrals, the letter said. Since the Occupational Safety and Health Standards Board meeting on May 21, CDPH said it had identified 84 more cases, four more deaths and 17 more transplants. "Most of these workers are young Latino immigrants with a debilitating, incurable disease acquired due to hazardous silica dust exposures in their workplaces," Pan wrote.

The draft follows Petition 609, filed Dec. 12, 2025, by the Western Occupational and Environmental Medicine Association on behalf of more than 600 occupational medicine physicians. The petition asked the Standards Board to prohibit fabrication and installation of engineered stone above 1% crystalline silica, arguing the material "is too toxic to fabricate and install safely" and that education and enforcement alone will not stop the epidemic. On May 21 the board granted the petition in part and directed Cal/OSHA to begin emergency rulemaking and convene advisory meetings; Cal/OSHA held a stakeholder advisory session July 31 in Oakland.

Cal/OSHA's April evaluation of the petition described artificial stone as typically 85% to 95% crystalline silica by weight, far above most granite, and said the disease progresses faster than classic silicosis. From Dec. 29, 2023, through Feb. 9, 2026, the division opened inspections at 135 fabrication shops and closed 127; it cited 120 of those shops (94%) and issued Orders Prohibiting Use at 20%, according to the evaluation. Those shops were only about 10% of an estimated 1,342 fabrication operations statewide. A permanent strengthening of section 5204 took effect Feb. 5, 2025, after an emergency temporary standard in December 2023.

Industry groups are pushing back on the draft's form even as they say they share the goal of protecting workers. The International Surface Fabricators Association, in a Sept. 17 statement and Sept. 29 comment letter, said it does not support the discussion draft as written and instead proposed a product-agnostic fabrication-shop licensing and third-party audit program. "Every party at this table agrees on the first thing that matters, no worker should lose their life for a countertop," ISFA CEO Laurie Weber said. "The disagreement has never been about whether workers deserve protection. It is about how we deliver it."

Australia banned the import, manufacture, supply, processing and installation of engineered stone above 1% crystalline silica in July 2024 after a similar outbreak. Cal/OSHA's petition evaluation said that ban simplified enforcement and spurred safer substitutes, but warned California can regulate workplaces, not the full supply chain, so a fabrication-only prohibition could push some work underground or out of state if slabs remain available for sale.

What happens next is still unsettled on the public calendar. The Standards Board meets Oct. 15 at 10 a.m. at the San Diego County Administration Center; the posted agenda lists elevator safety orders and other business but does not schedule the engineered-stone prohibition for adoption. The board's next noticed meeting after that is Nov. 19 in Monterey. Until a regulation is adopted and takes effect, the existing section 5204 silica controls for high-exposure trigger tasks remain the enforceable rule for California countertop shops.

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