From 2005 to 2011, Wisconsin had a six-year window where plaintiffs could sue manufacturers of white lead carbonate (a pigment formerly used in some paints) under a tort theory known as “risk-contribution.” Under this theory, plaintiffs can seek damages from a company that produced white lead carbonate used in paint even if the plaintiff cannot demonstrate that the company produced the pigment that caused an alleged injury. The Wisconsin Supreme Court adopted risk-contribution theory in a 2005 decision (Thomas ex rel. Gramling v. Mallett).

In 2011, the Wisconsin Legislature enacted a law that precluded the use of risk-contribution theory for lead paint cases. The Legislature attempted to make this law retroactive, but the Seventh Circuit determined that would violate Wisconsin’s Constitution, leaving manufacturers open to liability for claims filed between 2005 and 2011. About 170 lawsuits were filed on risk-contribution theory. Three of those went to trial in Milwaukee federal court as Burton v. DuPont, resulting in a $6 million judgement against three corporate defendants that, at various times, manufactured both white lead carbonate as well as paint containing that substance.

In April 2021, the Seventh Circuit Court of Appeals reversed the ruling, granting judgement as a matter of law to one defendant and ordering a new trial for the other two. The district court had allowed the plaintiffs to apply risk-contribution theory to the defendants’ manufacture of both white lead carbonate and paint containing the substance; the Seventh Circuit rejected this expansion of the Wisconsin Supreme Court’s ruling in Thomas. The Seventh Circuit also found that the District Court erred in allowing liability for negligence without proof of a product defect as well as allowing a strict liability claim without an accompanying duty to warn.