In a decision on Wednesday, U.S. District Judge Ruth Bermudez Montenegro in San Diego said consumers in the proposed class action failed to adequately plead that the grocery chain's chocolate posed an unreasonable safety hazard or were unfit to eat.

While the lack of a warning on labels can mislead reasonable consumers, "alleging that heavy metals can pose human health risks at some unidentified level does not mean the levels in [Trader Joe's] products pose a human health risk," she wrote.

The judge dismissed five claims brought on behalf of shoppers nationwide, including for violating California consumer protection laws and an implied warranty that the chocolate was safe to eat, but said they can try to amend their complaint.

Claims brought on behalf of Illinois, New York and Washington shoppers under those states' laws can proceed.

Lawyers for the plaintiffs did not immediately respond on Thursday to requests for comment. Trader Joe's and its lawyers did not immediately respond to similar requests.

Several chocolate sellers were sued by consumers after a Consumer Reports study in December 2022 found potentially harmful levels of lead, cadmium or both in dark chocolate bars, for people who ate more than one ounce of chocolate a day.

The metals can occur naturally in soil. Consumer Reports has said long-term exposure to them can lead to nervous system problems, immune system suppression and kidney damage, with greater danger to pregnant women and young children.

Godiva, Hershey, Lindt and Mars, which makes Dove chocolate, are among other companies that were sued over their dark chocolate.

The Trader Joe's case combined five lawsuits involving 17 law firms.

It alleged undisclosed levels of lead, cadmium and arsenic, another heavy metal, in eight dark chocolate bars, citing the Consumer Reports study and "independent laboratory" testing.

The case is In re Trader Joe's Company Dark Chocolate Litigation, U.S. District Court, Southern District of California, No. 23-00061.

(Reporting by Jonathan Stempel in New York; Editing by Frances Kerry)

By Jonathan Stempel