California may ban artificial stone countertops after lung disease outbreak

California is considering prohibiting the fabrication and installation of artificial-stone countertops — effectively banning the products — in response to an epidemic of the fatal lung disease silicosis among workers who cut, grind and polish countertop slabs before they are fitted into homes and businesses.

Silicosis is caused by the inhalation of pulverized silica, one of the most common minerals on earth. Public Health Watch, LAist and Univision were the first to disclose a silicosis cluster among Southern California countertop fabrication workers in December 2022. A year later, the California Occupational Safety and Health Standards Board adopted an emergency temporary standard that required the employers of such workers — most of whom are young, immigrant men — to suppress toxic silica dust with water and take other protective measures. That standard became permanent in December 2024.

Five months after the initial stories were released by Public Health Watch and its media partners, the California Department of Public Health had confirmed 69 cases of silicosis statewide. As of April 8, that number had grown to 542, with 29 deaths. More than half of these cases — 279 — came from Los Angeles County.

What is silica?

The silica that threatens the fabricators’ lungs comes from quartz, which is crushed and mixed with resins and pigments to make artificial stone — also known as engineered stone — a cheaper, more versatile alternative to natural stone like granite or marble. The ingredients are poured into molds, a process that allows for mass production of countertop slabs.

When a slab is cut, ground or polished in preparation for installation, a pestilent powder is released into the air and drawn into workers’ lungs, where it collects and causes slow suffocation. There is no cure for silicosis; the only procedure that can buy some victims time is a double-lung transplant, which is expensive, cumbersome and rarely prolongs life beyond 10 years.

Why is California considering banning engineered stone?

The Occupational Safety and Health Standards Board is scheduled to take video testimony from fabrication workers suffering from silicosis at its meeting Thursday in Santa Rosa. It is not expected to vote on a ban, however, any sooner than its May 21 meeting in Los Angeles.

Should California choose to ban engineered stone, it would be the first state to do so. Australia banned the material in 2024 after experiencing a silicosis outbreak that claimed an estimated 1,000 victims.

The standards board is required to respond to a petition submitted in December by the Western Occupational and Environmental Medical Association, a nonprofit that represents more than 600 physicians and other health experts in seven states. In that petition, the association asked the board to “prohibit all fabrication and installation tasks ... on engineered stone that contains more than 1% crystalline silica. This action is necessary in light of the continuing epidemic of silicosis that is causing disease and death among California fabrication workers ...” Engineered-stone countertops typically contain more than 90% crystalline silica, the most common and dangerous form of the mineral; another form, amorphous silica, is not believed to pose serious health risks.

Lawyers representing hundreds of sick workers and their families in litigation against countertop manufacturers say engineered stone cannot be handled safely.

“Artificial stone is too toxic to be safely fabricated,” said Raphael Metzger, who practices in Long Beach and won a $52.4 million jury verdict — the nation’s first — against 34 manufacturers in August 2024. “Every week I meet with about a half-dozen fabricators, many of whom have silicosis.”

“The silicosis crisis is not a failure of rules — it’s a failure of a product,” said James Nevin, based in Novato, California. The medical association’s “proposed ban works because it removes that hazard at its source. Every jurisdiction that has reduced disease has done so by eliminating crystalline silica artificial stone itself — not by pretending it can be used safely.”

Countertop manufacturers are not standing by quietly. In a March 27 letter to the standards board, Cosentino North America, part of Spain’s Cosentino Group, said, “Effective [workplace safety] standards already exist, but there are non-compliant fabrication shop owners that do not implement them and put their workers at risk.” With “the correct controls in place,” the company said, “engineered stone can be fabricated safely.”

Cal/OSHA enforces silica rule

California’s silica rule is enforced by the state’s Division of Occupational Safety and Health, known as Cal/OSHA. In a statement to Public Health Watch, a Cal/OSHA spokesperson said the agency had opened more than 140 inspections of fabrication shops since the emergency temporary standard took effect in December 2023. Those inspections unearthed more than 580 violations, the spokesperson said.

In a presentation to the standards board at its March meeting, Eric Berg, Cal/OSHA’s deputy chief for health, research and standards, said the agency had assessed a total of $1.8 million in penalties against fabrication shop owners alleged to have violated the silica rule. Stop-work orders were issued to 26 shops where dry-cutting of artificial stone — a prohibited practice — or inadequate respiratory-protection measures were observed, Berg said.

Last year, Cal/OSHA estimated that the state had 920 fabrication shops, employing some 4,600 workers.

It's unclear which way the standards board will go when the proposed ban comes up for a vote. In a February 27 letter, Chairman Joseph M. Alioto Jr. urged district attorneys in the seven counties that account for nearly 95% of the silicosis cases in California to pursue criminal charges against violators.

“Please do not be misled by the misdemeanor classification of [silica violations],” Alioto wrote. “These are no ordinary misdemeanor cases, as the science bears out. Dry-cutting on its own will result in serious injury in a majority of cases. That means that every successful misdemeanor you prosecute will shutter a violating employer and save workers’ lives.”

The medical association on whose petition the board must rule, however, argued that “education and enforcement alone will not be sufficient to curtail the escalating occupational health emergency caused by” engineered stone.

After Australia banned the material, alternatives with the same “quality, look and feel” but free of crystalline silica took its place, the petition says. If the standards board follows Australia’s lead, “it is highly likely that these safer products will be made immediately available in the California market, without significant economic consequences for fabrication businesses and their workers.”

Jim Morris is executive director and editor-in-chief of Public Health Watch, a nonprofit investigative news organization.