Mass litigation is every casualty insurer’s worst nightmare, conjuring up memories of the unending flow of asbestos litigation and the devastating effect it had on the industry. Today, though, we’re in what seems like the throes of another potentially unending mass litigation over the “forever chemicals,” per- and poly-fluoroalkyl substances (PFAS).

PFAS chemicals have been used in familiar brands such as Teflon and Scotchgard, and their nickname of the “forever chemicals” refers to their persistence in the environment but could just as easily refer to the amount of time the exposure remains on the liability insurance occurrence form. Many insurers are aware of the problem, at least as it relates to recent litigation over firefighting foam but also from historical exposure to some of the manufacturers of PFAS over the last 75 years, including Dupont and 3M.

Praedicat recently completed a massive data collection for its PFAS litigation tracker, a census of all state and federal complaints citing PFAS damage and filed in U.S. courts since the litigation began. The litigation has already reached epic proportions—with 5,153 complaints filed in 40 courts, naming 193 companies that span 82 industries—and has been running for more than 22 years, since the first case was filed on June 11, 1999.