In a proposed class action filed on Wednesday, Christopher Lazazzaro said he would not have bought or would have paid less for Hershey's Special Dark Mildly Sweet Chocolate, Lily's Extra Dark Chocolate 70% Cocoa and Lily's Extreme Dark Chocolate 85% Cocoa had Hershey disclosed their metals content.

Hershey did not immediately respond on Thursday to requests for comment on the lawsuit, which was filed in the federal court in Central Islip, New York.

Some studies suggest that the antioxidants and relatively low levels of sugar in dark chocolate could help prevent cardiovascular disease.

Lazazzaro, a resident of Nassau County, New York, sued two weeks after Consumer Reports unveiled the results of scientific testing of 28 dark chocolate bars for lead and cadmium.

The magazine said that while all 28 contained the heavy metals, 23 including chocolate from Dove, Godiva, Lindt and Trader Joe's contained potentially harmful levels of lead, cadmium or both for people who eat one ounce of chocolate a day.

Hershey's Special Dark bar and Lily's 70% bar were high in lead, and Lily's 85% bar was high in lead and cadmium, the magazine said.

Lazazzaro said reasonable consumers would be turned off by such levels because they pose a "serious health risk," and that consumers rely on Hershey to be truthful about ingredients in its products.

The lawsuit seeks at least $5 million of damages, including at least $500 per transaction under New York law.

Hershey bought Lily's for $425 million in June 2021.

Lazazzaro's lawyers did not immediately respond to requests for comment, including as to whether other lawsuits are planned.

The case is Lazazzaro v Hershey Co, U.S. District Court, Eastern District of New York, No. 22-07923.

(Reporting by Jonathan Stempel in New York; Editing by Leslie Adler)

By Jonathan Stempel