Of the emerging litigation topics across America, one of the more burdensome on our judicial system involves PFAS, or per- and polyfluoroalkyl substances. Though PFAS have been around since the mid-20th century, they have recently exploded as a source of litigation. The purpose of this article is twofold: to take a look at recent developments in PFAS litigation since the publication of A brief primer on PFAS litigation: Trends and future disputes in 2022, and to provide an overview of how—thus far—plaintiffs have succeeded (or failed) in developing legal theories.
Litigation Summary — Multi-district Litigation (MDL)
Currently, the epicenter of PFAS litigation is the ongoing MDL in the U.S. District Court for the District of South Carolina, where nearly 10,000 PFAS cases have been consolidated (9,896 pending claims as of November 1, 2024). The MDL centers on claims of PFAS-contaminated groundwater in cities across America, caused by the seeping of specialized aqueous film-forming foam used for firefighting, known as "AFFF" or "A-Triple F." Though the sheer number of cases involved may suggest otherwise, the MDL is limited only to PFAS contamination caused by AFFF. And notably, rural communities who rely on well water are not in the MDL. After years of percolating through the court, 2025 is slated as the year to test several bellwether cases: kidney and testicular cancer cases, which are set for October 2025, and "Telomer Water Provider" cases (the latter having a March 2025 presumptive trial date that did not materialize). Summary judgment and Rule 702 motion rulings are likely to be the next development as the trial dates approach.
MDL — Partial Settlement
As the trial deadline approaches, so too does the pressure to settle. Some of the claims in the AFFF MDL were resolved with settlements surpassing $11 billion. The settlement with PFAS-manufacturer 3M contained several limitations concerning water suppliers, and as discussed in Bloomberg Law by Thompson Coburn Partner Suzanne Galvin, as part of the 3M settlement, "a water utility, which opts into the settlement, can't demand more money from the [settling] company" for litigation involving the same issues in the future. Even with such an astronomical settlement, the "peace at any price" method may not last long: AFFF claims only represent a fraction of the existing types of PFAS compounds. And even excluding the AFFF compounds at issue in these cases, over 9,000 PFAS compounds remain. The lure of high-settlement offers and existence of a bevy of other compounds are likely to entice future PFAS-inspired lawsuits.
Broader PFAS Litigation Trends
Firefighting foam is just the tip of the PFAS iceberg. Unsurprisingly, lawsuits nationwide span a wide range of theories and industries. Initially, plaintiffs primarily sued the PFAS manufacturers, such as 3M, DuPont/Chemours, and Tyco. Plaintiffs then added lawsuits against "downstream" commercial manufacturers who used PFAS during the manufacturing process, and against other entities that plaintiffs claim introduced PFAS in the stream of commerce as retailers of a product containing a PFAS compound. Food and food packaging are frequent targets, as are beauty products—but PFAS litigation spans a wide range of products, from clothing and carpet to tampons and baby wipes.
Plaintiffs' Lack of Traction
With the science and legal theories surrounding PFAS far from settled, it comes as no surprise that plaintiffs have experienced difficulty determining their best theories of liability, a flaw common with pattern litigation. Many PFAS cases have experienced early dismissals—through early settlement or otherwise—and relatively few have made it past the motion-to-dismiss stage and are proceeding with discovery. In fact, of one hundred PFAS cases in the Appendix below that Thompson Coburn recently surveyed, only twenty-two remain active—and only eight of those are currently proceeding past the motion-to-dismiss stage. Further, of the dismissed cases, only three involved class settlements. While the list of one hundred cases in the Appendix is not exhaustive, it provides a helpful representative sample of how plaintiffs have fared in these types of cases.
For example, class actions were filed in Illinois and Southern California against McDonald's and Burger King, alleging contamination from PFAS used in fast food packaging to prevent french-fry grease from leaking through fry cartons and to prevent melted cheese from sticking to burger wrappers. Before the courts could rule on the restaurants' respective motions to dismiss, the plaintiffs voluntarily dismissed both cases (McDonald's with prejudice, Burger King without prejudice)—leaving unresolved the restaurants' raised issues of lack of standing, federal preemption, and failure to plead with specificity. And plaintiffs were left without any hope of a big payout from class certification.
Meanwhile, in New York, plaintiffs sued Ornua Foods, alleging that PFAS in butter packaging migrated into the company's Kerrygold Butter. The plaintiffs brought breach-of-warranty and unjust-enrichment claims, as well as claims under various state consumer-protection statutes. Their general theory was that the presence of PFAS made claims that the butter was "pure" misleading. But the plaintiffs voluntarily dismissed the case with prejudice in August 2024 after the court allowed all but their claim for injunctive relief to proceed, and before any class was certified.
One ongoing case, a purported class action, was filed in late 2022 against Post Consumer Brands LLC and The J.M. Smucker Company alleging that they misled consumers by including healthful labeling statements on pet food products containing titanium dioxide as an ingredient. Plaintiffs further allege that the products' packaging contained per- and polyfluoroalkyl (PFAS). Discovery is ongoing in the case, which is now on a third amended complaint. Plaintiffs' motion for class certification is currently due in mid-2025.
Another ongoing purported class action involves Prime Hydration LLC. Plaintiffs alleged that Prime sports drinks contained PFAS, and that its labeling and marketing were misleading. In May 2024, the court held that the plaintiffs did have standing, but otherwise dismissed all of their claims except for breach of implied warranty. Prime then filed a motion for judgment on the pleadings, which has been fully briefed since December 2024. If the court denies that motion, discovery and class-certification briefing will likely take place late in 2025. As shown in the Appendix below, several other ongoing cases have class-certification deadlines in early 2026.
Litigation Challenges for Plaintiffs' Counsel
The broad scope of ongoing cases in large-scale litigation like this offers a distinct advantage to defense attorneys: it reveals the common legal theories that plaintiffs are relying on across the country, as well as the hurdles that plaintiffs face.
In these types of PFAS cases, Plaintiffs typically rely on three theories of liability: (1) nuisance, (2) fraud/breach-of-warranty and/or consumer-protection statutes, and (3) medical monitoring. However, as illustrated by the many dismissals noted in the Appendix of cases below, plaintiffs have encountered hurdles such as lack of standing, lack of product-specific testing, heightened pleading requirements for fraud and consumer-protection statutes, and—in some states—the inability to bring medical monitoring claims without a present physical injury. Yet, the sheer number of cases being filed—and the ever-expanding list of products involved—indicates that PFAS litigation, much like the chemicals it centers around, will likely last for years to come.
Parallel to Opioid Litigation
Experienced litigators detect a direct parallel here to Opioid litigation, where plaintiffs began with a nuisance claim (in part, to enable plaintiffs to seek equitable remedies) against opioid manufacturers, and then worked down the list of other available defendants in an attempt to recover from retailers and other seemingly less-responsible parties. (See recent success in opioid litigation in Ohio based on nuisance theories.) Because opioid plaintiffs frequently struggled to link these other defendants' conduct with the alleged harm, nuisance claims often failed, forcing plaintiffs to turn to other legal theories.
Similarly, plaintiffs in PFAS litigation have often failed to link alleged PFAS contamination to a particular defendant's products or operations, or have failed to link a defendant's actions to the alleged harm. For example, in Suez Water v. E.I. du Pont de Nemours & Co., the court dismissed the plaintiff's nuisance claims, citing insufficient evidence that the defendant knew about the manufacturers' use or disposal of PFAS. The court found that the defendant had only introduced a lawful product into market, and had not played a substantial role in creating the nuisance. Declining to heap liability on any defendant for engaging in lawful business practices, the court refused to set a precedent for punishing any defendant who had minimal involvement in introducing PFAS to the market.
Recently, plaintiffs have turned to medical monitoring—a relatively new claim in the context of PFAS litigation. Notably, under medical monitoring theories, plaintiffs allege that early detection of diseases could deter future illness; they do not allege an actual present injury. Instead, the theory is that some substance has produced subcellular changes that increase the risk of future disease, necessitating medical monitoring. The states are split into three roughly equal camps when it comes to allowing medical monitoring claims: some states allow medical monitoring claims without proof of present physical injury1, other states reject such claims2, and the remaining states are either divided on the issue or have yet to address it.3
One state that recently rejected this theory was New Hampshire, after a winning argument by Thompson Coburn LLP's John Galvin before the state supreme court. As John Galvin persuasively argued, "you can't sue someone because you might get sick in the future. It's after you've sustained an injury that you have a cause of action, a claim against someone." The truth is, Galvin continued, testing everyone for PFAS would show that "in excess of 95% of the folks in America are going to have some level of PFAS in their system. If every one of those people, therefore, has standing to bring a lawsuit against everyone involved in using PFAS over the years, [we are] going to have runaway lawsuits."
To be sure, other states have recognized such a remedy, inviting negative unintended consequences. That is because "[o]ur civil justice system is not very well equipped to handle something like this. We're very good when somebody's got an actual injury, and they think there's an actual cause, and we go into court and decide if that person's entitled to money. But when our civil justice system tries to go in and solve public health issues on a broader scale, we have a record of not doing a very good job with that," John Galvin informed the Connecticut Law Tribune.
Issues With Testing
PFAS testing methods also continue to evolve. Certain types of PFAS can be identified through a "targeted" analytical method involving liquid chromatography and tandem mass spectrometry. Although this method accurately measures concentration levels, it is expensive and can only detect a few dozen of the thousands of different PFAS compounds. Another available testing method involves measuring "total oxidizable precursors." But this method is also expensive, and is even more labor-intensive. Because these two testing methods are so expensive and time-consuming, lower-cost alternatives have been developed that measure "total organic fluorine" as a sort of proxy for total PFAS contamination. But these cheaper, faster methods suffer from numerous limitations. For example, some of these alternative methods are unable to distinguish between organic and inorganic fluorine, or are unable to detect specific PFAS types. Some cannot even accurately distinguish between PFAS and other substances. Further, measuring "total organic fluorine" is less sensitive than the more targeted testing methods.
Testing frequently plays a key role at the outset of cases involving alleged PFAS contamination. Courts closely scrutinize allegations regarding testing for the presence of PFAS in the product a plaintiff purchased, or in the plaintiff's body; a lack of testing or deficient testing provides an easy way for courts to dismiss a case for lack of standing because there is no injury in fact. And for the cases that have made it past the motion-to-dismiss stage, the topic of PFAS testing methods will play a prominent role as parties begin to address the cases' merits and develop expert testimony. These issues will only compound throughout the year, with discovery closing in late 2025 in some cases, and expert deadlines due in early 2026.
Looking to the Future — Prepare Now
Looking ahead, it is likely the scope of PFAS litigation will only expand, particularly in states that allow medical monitoring claims even without proving present physical injury. Through trial and error, plaintiffs are sure to get more creative—both in their legal theories and who they bring cases against. Thus, companies should take proactive steps to assess how PFAS might impact their operations. This includes reviewing state and federal regulations; conducting thorough assessments of products, processes, and supply chains for the presence of PFAS; and documenting their findings. To manage potential liability, companies will need to deepen their understanding of the presence of PFAS in their operations and adjust corporate strategies accordingly.
The risk of PFAS-related litigation even extends to transactional law. In the context of mergers and acquisitions, companies should recognize that PFAS liability is another risk to consider when evaluating deals, and should factor those risks into negotiations. Additionally, they should work with legal and risk-management teams to identify, insure, and mitigate PFAS-related liabilities. Finally, companies should assess indemnity issues and ensure they have appropriate insurance coverage in place to address the potential financial implications of PFAS litigation. Finally, companies should be prepared to address the PFAS problem once identified, else they could face lawsuits for failing to act despite having knowledge about PFAS contamination in their products.
Policy Considerations
PFAS is ubiquitous. An estimated 98% of the U.S. population have detectable concentrations of PFAS in their blood. At this point, identifying the source of the PFAS in each person—in other words, finding the responsible party—is an impossible task. And unlike with opioids, which can be traced in discrete pill form, PFAS compounds permeate an array of products, packaging, and even drinking water. Holding opioid manufacturers and retailers liable in court was a monumental task; to do so with PFAS may prove even more difficult. The already burdened court system may also buckle under the undue burden PFAS litigation places upon it. This begs the question: is this just a situation where the societal issue to be addressed only serves to make certain MDL plaintiffs' counsel wealthy? If plaintiffs' stated goal is health and safety—and not just a payout—then policymakers should be the ones to address PFAS, perhaps by taking the burden off the court system and handling the PFAS problem through legislation, not litigation.
Footnotes
1. States that allow medical monitoring despite a lack of present physical injury include Arizona, California, Colorado, District of Columbia, Florida, Maryland, Massachusetts, Minnesota, Missouri, Nevada, New Jersey, New York, Ohio, Pennsylvania, Utah, Vermont, and West Virginia.
2. States that reject medical monitoring without present physical injury include Alabama, Arkansas, Illinois, Kentucky, Louisiana, Michigan, Mississippi, Nebraska, New Hampshire, North Carolina, North Dakota, Oklahoma, Oregon, South Carolina, Texas, Virginia, and Wisconsin
3. States that have unclear or divided law on the subject include Alaska, Connecticut, Delaware, Georgia, Hawaii, Idaho, Indiana, Iowa, Kansas, Maine, Montana, New Mexico, Rhode Island, South Dakota, Tennessee, Washington, and Wyoming.
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