Doctors Petition California to Ban Countertop Material Linked to Deadly Disease

A medical association has petitioned California to prohibit the use of a popular countertop construction material linked to an aggressive lung disease disabling and killing stoneworkers. The campaign escalated pressure on the state to follow Australia, which became the first country to ban engineered stone last year after facing a similar health crisis.

California has the U.S.’s strictest regulations to prevent workers from inhaling toxic silica dust — generated by the cutting, polishing and grinding of engineered stone slabs to make kitchen countertops, bathroom vanities, fireplace surfaces and other products. Most countertop fabrication shops, however, don’t have the money or capacity to comply with the rules, leaving thousands of stonecutters at risk of contracting silicosis, according to the Western Occupational & Environmental Medical Association.

“The evidence is now clear that engineered stone containing crystalline silica is too toxic to fabricate and install safely, and education and enforcement alone will not be sufficient to curtail the escalating occupational health emergency caused by this product,” WOEMA’s Dec. 12 letter to regulators said. The association represents more than 600 occupational safety physicians and other experts in seven western states.

The doctors requested that the state body that adopts new job safety rules to start the process to ban all fabrication and installation tasks on engineered stone containing more than 1% crystalline silica, similar to Australia’s policy.

The Occupational Safety and Health Standards Board, which declined to comment on WOEMA’s letter, has up to six months to review and decide. The proposal is likely to face stiff opposition from manufacturers, distributors and fabricators of engineered stone, also known as quartz or artificial stone.

Artificial stone represents a growing multibillion-dollar market in the U.S., with increasing demand expected in California due to the rebuilding effort in Los Angeles after the massive fires in January 2025. More than half of the silicosis cases in the state are located in Los Angeles County.

Laurie Weber, who directs the International Surface Fabricators Association, said Australia’s model is not directly transferable to the U.S. economy, and that more research is needed to understand what would happen if hundreds of small and mid-size fabrication businesses suddenly had to stop working with their primary material.

“ISFA does not believe a ban is the answer. The problem is not the material. The problem is employers ignoring the law and a lack of enforcement resources to ensure compliance,” Weber said in a statement. “Before California considers a prohibition that would reshape an entire segment of the construction economy, we respectfully request clarity on how WOEMA determined that engineered stone cannot be fabricated safely — even in shops fully compliant with Cal/OSHA’s existing silica standard.”

ISFA and others in the industry instead support a licensing program, in which only shops certified to handle artificial stone following regulations have access to it. A recent law signed by Gov. Gavin Newsom that addresses the rise of silicosis through education and enforcement initially included a certification system — but that component was removed from the final draft.

About 450 silicosis cases have been confirmed among stoneworkers in California since 2019, and regulators expect the numbers could rise to between 1,000 and 1,500 within the next decade. Nearly all of those sick are Latino men, many immigrants lacking permanent legal status, who didn’t know about the hazards of working on crystalline silica products. Twenty-five stoneworkers died, and dozens received lung transplants, according to the California Department of Public Health.

“As long as this dangerous material remains available and is purchased and used in California, it’s inevitable that people will continue to be exposed and die,” Robert Blink, an occupational medicine doctor in San Francisco and former WOEMA president, told KQED. “There’s always resistance to change. But when you’ve got something this dangerous out there that’s literally killing people … we’ve got to stop this from going up. This is not a time for small measures, frankly.”

Engineered stone can contain more than 90% crystalline silica, much more than natural stones such as marble. The factory-made material’s popularity has skyrocketed because it is stain-resistant, produced in attractive colors and designs and is often cheaper than natural stones. But many consumers are unaware of the hazards that artificial stone dust poses to the workers who shape and install their countertops.

Growing scientific evidence has shown that the silica dust released by the material is so toxic that small amounts of exposure are enough to make workers sick. The tiny airborne particles can penetrate filter masks and lodge in the lungs, causing progressive scarring and injury in workers, some as young as their 20s.

Dozens of silicosis cases have also been reported by doctors in Illinois, Utah, Colorado, Massachusetts, as well as other states that are not tracking the disease as systematically as California’s public health authorities. Those figures are widely believed to be underreported. Israel, Spain and other countries have also seen a surge in silicosis tied to engineered stone. Medical experts in the UK are urging authorities to prohibit the use of the material.

James Nevin, an attorney at Brayton Purcell, a firm that represents hundreds of sick workers suing major manufacturers and distributors of artificial stone, said clients are located in 16 other states, including New York, Nevada, Florida, Kentucky and Hawaii.

California currently bans the dry cutting of engineered stone and mandates the use of wet methods — machines that submerge or cover the material’s surface with water to suppress dust. Employers are also required to implement local exhaust ventilation, ensure employees wear powered air-purifying respirators and take other measures.

But Cal/OSHA inspectors have found most of the 120 shops they’ve visited in the last two years were violating the rules, which fabricators and doctors consider too expensive and challenging for many employers to follow. California has about 4,600 countertop fabrication workers.

Major manufacturers, such as Israel-based Caesarstone, did not immediately return requests for comment on the California ban proposal, but publicly opposed a prohibition in Australia. A spokesperson for Cosentino, a company headquartered in Spain, also declined to comment, but told KQED last month that silicosis is preventable when proper safety and health measures are in place to protect workers.

Both companies, which face hundreds of lawsuits by workers claiming silica-related injuries in the U.S. and other countries, have developed crystalline silica-free products for the Australian market but continue to sell high-silica engineered stone in the U.S.

Doctors who’ve followed the issue argue that the safer alternatives have similar qualities, appearance and cost to traditional engineered stone and could be made immediately available in California, without significant economic consequences for fabrication businesses.

Policymakers have publicly expressed dismay at the rising number of silicosis cases in the state, but have not favored a prohibition so far. Occupational Safety and Health Standards Board Chair Joseph Alioto Jr. said that the state should focus its resources on expanding Cal/OSHA enforcement of current silica regulations. Alioto recommended the agency partner with local public health departments and district attorneys to assist with investigations.

“We currently have a regulation to do stuff. We just need to get out into the field and do it,” said Alioto, an attorney in San Francisco, during a Nov. 20 meeting. “We just need boots on the ground to police this.”

Newsom’s office declined to comment on his stance on a ban on artificial stone, referring questions to the Public Health Department. An agency spokesperson said that they are tracking the silicosis situation closely.

Lopez, a 43-year-old former stonecutter who was diagnosed with silicosis last year, said he believes removing hazardous artificial stone from fabrication shops could save lives. The once-active father of four is now confined to his East Bay home, waiting for a double lung transplant, unable to work and reliant on an oxygen supply machine to breathe.

“If I’d known about the seriousness of this disease from the beginning, I wouldn’t have worked in this field, in the stone industry, because I wouldn’t have wanted to get sick like I am now,” said Lopez, an immigrant who lacks permanent legal status, who cut countertops in California for decades. KQED is withholding his full name because he fears losing medical care if federal authorities arrest him.

“If they have the possibility of selling other products that contain zero silica, that would be better, so that people don’t get sick,” he said.