Some of the most popular materials for countertops may soon be on the chopping block in California. Engineered stone products such as Caesarstone, Cambria, and Silestone have been linked to the lung disease silicosis, prompting California regulators to consider a ban on the materials. Regulators there have found at least 562 associated silicosis cases to date, with 31 confirmed deaths.

Engineered stone countertops are often marketed as “quartz,” and although they contain stone, they are not slabs of rock like granite, marble, or soapstone. Instead, they are made from crushed rock particles and binding agents like resin. This allows them to have the look of stone without the weight or upkeep that natural stone requires, making them popular alternatives for kitchen builds and remodels. However, engineered stone contains much higher levels of crystalline silica than natural stone.

The danger to workers comes when they cut or shape engineered stone with power tools like saws or grinders. This releases miniscule particles of crystalline silica that workers can inhale. The silica dust can cause silicosis, an irreversible lung disease. While this risk can be mitigated in the workplace through appropriate safeguards, the California Department of Health discovered that half of the workshops they inspected had at least one employee who was exposed to silica dusts above the permissible exposure limit.

One country - Australia - has already banned the manufacture and installation of engineered stone products. This ban "should prevent approximately 100 lung cancers and 1,000 silicosis cases over the lifetime of Australian workers from across the entire supply chain, from factory workers to tradespeople working in Australian homes," said  professor Tim Driscoll, the chair of Cancer Council’s Occupational and Environmental Cancers Committee.