DES MOINES ? Owners of Teflon-coated pots and pans in 15 states are seeking to have their cases combined in a $5 billion class-action lawsuit claiming DuPont Co. failed to disclose possible health risks from using the nonstick cookware.

The lawsuits claim DuPont continued to tell the government and consumers for years that Teflon was safe even though its own studies showed the material could become toxic when heated “enough to fry an egg,” according to Des Moines attorney Kim Baer, who represents six plaintiffs from Iowa.

U.S. Magistrate Celeste Bremer didn’t signal at a hearing Thursday when U.S. District Judge Ronald Longstaff will rule on the request to certify the cases as a class action.

DuPont attorney Adam Hoeflich of Chicago said Teflon has a 40-year history of safe use.