United States Court of Appeals For the Seventh Circuit ____________________ Nos. 20-1774, 20-1776, 20-1777, 20-1780, 20-1781, 20-1782, 20- 1783, 20-1784 & 20-1785 GLENN BURTON, JR., RAVON OWENS, AND CESAR SIFUENTES Plaintiffs-Appellees,

v. E.I. DU PONT DE NEMOURS AND COMPANY, INC., THE SHERWIN- WILLIAMS COMPANY, AND ARMSTRONG CONTAINERS, INC. Defendants-Appellants. ____________________

Appeals from the United States District Court for the Eastern District of Wisconsin. Nos. 07-CV-0303, 07-CV-0441, 10-CV-0075 — Lynn Adelman, Judge. ____________________

ARGUED DECEMBER 9, 2020 — DECIDED APRIL 15, 2021 ____________________

Before WOOD, SCUDDER, and ST. EVE, Circuit Judges. ST. EVE, Circuit Judge. These sprawling toxic-tort cases take us into the weeds of Wisconsin products liability law. The product at issue is white lead carbonate—a dry white powder historically used as the “pigment” in many lead-based paints. Paint has two essential components: the pigment, which hides 2 Nos. 20-1774 et al. and protects the painted surface, and the liquid “vehicle,” which allows the pigment to be spread across the surface. Over time a consensus developed that lead-based paints were toxic and posed especially great dangers to young children, who were prone to chewing paint flakes or putting scattered lead dust into their mouths during critical stages of brain de- velopment. These dangers led the federal government to ban lead-based paint for residential use in 1978. Wisconsin fol- lowed suit two years later. Even after these bans, however, lead-based paint remained on the walls of many homes throughout the United States. The plaintiffs in these consolidated cases are three young men who grew up in Milwaukee homes that had lead-based paint on the walls. They were diagnosed with lead poisoning as young children in the 1990s or early 2000s. Years later, they filed these lawsuits against several manufacturers of white lead carbonate, seeking compensation for brain damage and other injuries resulting from their ingestion of lead paint par- ticles. The plaintiffs identified the paint pigment in their childhood homes as white lead carbonate, but they could not identify the specific company responsible for manufacturing the white lead carbonate that they ingested. To overcome this failure of proof, they relied on Thomas ex rel. Gramling v. Mal- lett, 701 N.W.2d 523 (Wis. 2005), in which the Wisconsin Su- preme Court adopted a “risk-contribution” theory of liability for plaintiffs suing manufacturers of white lead carbonate. The risk-contribution theory modifies the ordinary rule in tort law that a plaintiff must prove that a specific defendant’s con- duct caused his injury. It instead seeks to apportion liability among the “pool of defendants” who could have caused the injury. Nos. 20-1774 et al. 3

After years of pretrial litigation, the plaintiffs went to trial against five manufacturers of white lead carbonate. The jury found three of the manufacturers liable and awarded the plaintiffs $2 million each. The three defendants found liable (E.I. du Pont de Nemours and Company, Inc., the Sherwin- Williams Company, and Armstrong Containers, Inc.) now ap- peal. They challenge a long list of the district court’s pretrial, trial, and post-trial rulings. We see no error in many of these rulings, and we commend the district court for its thoughtful attention and diligent effort throughout this complex case. Nonetheless, we hold that the court committed three signifi- cant legal errors about the scope of Wisconsin products liabil- ity law. These errors shaped the trial and impermissibly ex- panded the defendants’ potential liability. Alon