Artificial Stone Silica Suits Set Up Insurance Coverage Fights

Powerhouse insurance companies are racing to court to limit their exposure to high-stakes litigation by hundreds of workers who said they developed chronic lung diseases after handling artificial stone countertops popular in US homes.

Silica-related lawsuits against makers and distributors of engineered stone products have flooded California courts, especially after a Los Angeles jury returned a $52 million verdict in August 2024 in a case against several manufacturers.

Silicosis litigation in the early 2000s prompted many liability insurers to add silica exclusions in their policies. Carriers are now hoping to rely on those provisions to deny coverage for the worker cases against manufacturers and distributors such as Cambria Enterprises LLC and the US units of LX Hausys Ltd. and Caesarstone Ltd.

At least eight coverage disputes over the stoneworker claims—including suits involving units of QBE Insurance Group Ltd., Liberty Mutual Insurance Co., and Travelers Cos.—are pending before the US District Court for the Central District of California, according to a Bloomberg Law review. The court is set to hear motions for judgment on the pleadings in several cases next month.

The pending motions may be “existential” for small and medium-sized businesses, said Jeff Kiburtz, a policyholder lawyer at Pillsbury who is involved in the litigation. “It’s hard to imagine how a lot of them will continue in existence” without insurance coverage for the claims, he said.

Some related coverage cases have been filed in California state court and federal courts in other states such as Virginia and New York, although they primarily concern underlying stoneworker suits in California.

The prospect of having to cover the mounting claims is likely driving insurer filings. An early ruling on insurance coverage issues in March that was favorable to carriers prompted additional declaratory actions by insurers as well as distributors and manufacturers of artificial stone countertops.

Artificial stone contains about 93% crystalline silica, more than double the amount in granite, making it “extremely hazardous” for workers who inhale dust from the products, according to a fact sheet from California’s Department of Industrial Relations. Around 300 California workers making countertops from artificial stone developed silicosis from January 2019 through March 2025, including 15 people who died, the department said.

Silica, Pollution Exclusions

In the California federal court’s March ruling on the pleadings, Judge Mónica Ramírez Almadani held that a silica exclusion barred coverage for underlying worker claims.

But the manufacturer in that case, Francini Inc., was granted leave to amend and has since broadened its argument.

On the second go-around, Francini said the underlying suits against it don’t allege injuries caused solely by silica, but also by metals and VOCs, which means the suits are potentially covered.

The expanded arguments on coverage reflect broader allegations in the underlying worker suits, with some recent complaints placing a greater emphasis on nonsilica irritants and alleging discrete injuries. Plaintiff firms Metzger Law Group and Brayton Purcell LLP are leading the charge in the underlying litigation, according to Bloomberg Law’s review.

Insurers typically have a duty to defend if any portion of a lawsuit is potentially covered. That means the long-standing silica exclusion may be insufficient to knock out coverage, policyholder lawyers said.

“If there are other possible causes of damages that are being alleged, the silica exclusion wouldn’t apply unless it clearly has language that would apply to these other claims,” said Benjamin Fliegel, a policyholder-side partner at Reed Smith LLP.

Whether there is coverage will ultimately come down to the specific injuries alleged in the underlying litigation and policy language at issue in each case, according to Fliegel.

Some carriers have also raised the pollution exclusion in their policies as a coverage defense. They are unlikely to succeed on that argument in California, however, because the state’s courts typically only apply the pollution exclusion to claims over traditional environmental contamination, Kiburtz said.

If insurers fail to knock out the stonemakers’ coverage bids early on, the suits “will probably move into a lower-grade sort of litigation that’s common in many of these long-term, long-tail cases,” he said. “Everybody accepts that there’s at least defense coverage, and then you try to figure out how to divvy up the loss and who should be paying for which claims.”