California is poised to become the first U.S. state to ban the production and installation of manufactured quartz countertops, following increasing concerns over a deadly lung disease affecting workers who cut the material. The move comes as the state's Occupational Safety and Health Standards Board prepares to adopt an emergency regulation slated for an October vote.

The proposed rule would restrict manufactured stone products containing more than 1 percent crystalline silica, a component abundant in engineered quartz. When slabs are cut, crystalline silica dust is released into the air, lodging in workers’ lungs and triggering a severe immune response. The resulting scarring, known as silicosis, progressively damages lung tissue, often necessitating single or double lung transplants once diagnosed.

Since 2019, California has confirmed 657 cases of silicosis and 35 related deaths among countertop workers, according to the state’s Department of Public Health. The affected employees are typically found in small fabrication shops that cut stone slabs to customer specifications, many of which have not complied fully with existing safety regulations. Workers often have precarious immigration status, complicating enforcement and outreach efforts. Cases of silicosis have led to a surge in lawsuits, with some awards reaching multi-million-dollar verdicts.

Supporters of the ban argue that current legal requirements for safer processing and controls are insufficient due to low compliance rates and the fragmented nature of the industry. Denise Gomez, a spokesperson for California’s Department of Industrial Relations, which advocates for the ban, highlighted the urgent need to protect workers from this hazardous product. Dr. David Michaels, a former federal OSHA administrator, described the pending regulation as a significant step that could influence regulations in other states and push manufacturers, retailers, and consumers toward safer alternatives.

Manufacturers and distributors of engineered stone, however, contend that the product itself is safe when properly handled. They place responsibility on the small fabrication workshops farther down the supply chain for the rise in silicosis cases, emphasizing that the cutting process is the main risk factor. Cambria, Minnesota’s largest U.S. engineered stone producer, has opposed the ban and lobbied lawmakers for legislation that would protect the industry from liability related to silicosis cases. The company argues the issue lies with fabrication methods rather than the stone itself.

Engineered quartz countertops, a popular alternative to granite and marble, often contain recycled materials such as glass, which some consider safer options. Australia implemented a ban on quartz countertops in 2024, followed by a complete import ban starting in 2025. Most quartz products sold in the U.S. are imported and distributed through a mix of home improvement stores and smaller suppliers before reaching fabricators.

The California regulation, pending brief state review before enforcement, would mark a significant regulatory milestone in addressing workplace health concerns tied to engineered stone fabrication.