DOVER, Del. (AP) — The DuPont Co. massively downplayed the cost of environmental liabilities with which Chemours would be saddled when DuPont spun off its former performance chemicals unit in 2015, according to a lawsuit unsealed Friday.

The maximum liability exposure figures that DuPont certified prior to the spinoff have proven to be “systematically and spectacularly wrong,” Chemours alleges.