The Sixth Circuit issued an order on September 9, 2022 granting review of a class certification from March 7, 2022 that certified a class of roughly 11.8 million Ohio residents claiming injuries from per- and polyfluoroalkyl substances, or PFAS.


Filed in 2018 in the Southern District Court of Ohio, the lawsuit alleged the named defendants (large chemical companies) manufactured and distributed PFAS substances despite knowing the dangers, and engaged in efforts to mislead the public and regulators about the alleged harms from PFAS substances.  The plaintiff sought to certify a nationwide class of every individual in the United States with PFAS in their blood and sought injunctive relief through funding by the defendants for a “science panel” to study the effects of PFAS and potentially provide medical monitoring to every member of the class.

The district court judge certified a class of every individual “subject to the laws of Ohio” whose blood contains 0.05 parts per trillion PFOA (a specific PFAS) and at least 0.05 parts per trillion of any other PFAS (amounts noted as currently undetectable with available technology).  Additionally, the plaintiff admitted that he did not know which defendant (if any) caused the PFAS in his blood, and has not alleged any health condition as a result of the exposure.  Rather, he alleged the levels of PFAS in his blood causes him to face a “risk of developing various diseases.”

The defendants petitioned for interlocutory review of the class certification advancing four arguments.  First, the defendants argued that the named plaintiff lacks standing because he failed to show an injury in fact, his asserted injury cannot be traced to the defendants, and that an Article III court cannot order the remedy sought.  Second, the defendants argued the class is not cohesive and cannot satisfy Federal Rule of Civil Procedure 23(b)(2) because the class members were allegedly exposed in different ways, in different amounts, to different substances, and at different times.  The defendants pointed out that they would also likely suffer different outcomes based on individual factors.  Third, the defendants alleged that the plaintiff’s vague description of the remedy fails to describe the injunctive relief sought.  Fourth, the defendants argued that the district court failed to adequately consider the “preclusive effect of a non-opt-out class” regarding possible claims of absent class members when it certified the class.

The Sixth Circuit’s Order

On defendants’ first argument, the Sixth Circuit found “sufficient ‘weakness’” in the plaintiff’s standing to merit further review.  Regarding the alleged injury, the Sixth Circuit found that the plaintiff’s allegations of increased risk of disease based on certain PFAS in his blood and the request for a science panel to be at odds – he simultaneously claims to be sufficiently likely to develop a disease and thus injured, but requested a science panel to determine whether he is at the risk.  Additionally, the requested science panel would not appear to be capable of redressing his injury (PFAS in his blood).  On traceability, the Sixth Circuit also pointed out that the plaintiff could not establish who caused his alleged injury, and his exposure could be the result of a “litany” of exposure pathways not involving the defendants.

Regarding defendants’ second argument on class cohesion, the Sixth Circuit expressed serious doubts in whether commonality could exist among the class with respect to exposure and relief.  Even if one class member could prove an elevated risk of injury given the PFAS in their blood, such a finding would not necessarily prove that elevated risk for other class members given a variety of factors impacting risk, including age, genetics, medical history, lifestyle, and time of exposure.

The Sixth Circuit also questioned whether plaintiff’s description of the remedy was sufficiently specific to certify the class.  The plaintiff argued that they need only request an injunction ordering defendants to pay for a science panel and medical monitoring for individuals in need as determined by the science panel.  The Sixth Circuit noted instead that relief must be described in “reasonably particular detail” when it comes to class-wide injunctions, and found the district court’s conclusions subject to serious dispute

Though the Sixth Circuit did not address the defendants’ fourth argument, it noted that precedent regarding the “death knell” of litigation counseled in favor of an interlocutory appeal.  The term is applied in cases where failure to certify a class would cause plaintiffs to abandon their claims.  Here, the Sixth Circuit acknowledged that a “reverse death knell” situation existed – by certifying the class, the threatened massive liability would induce the defendants to settle rather than defend the action on the merits.  Two factors weighing heavily on this finding were the size of the class and scope of potential liability.  The Sixth Circuit also determined that the district court’s grant of class certification weighed in favor of an interlocutory order.

Based on these findings, the Sixth Circuit granted defendants’ request to present the case before a merits panel for review.


The Sixth Circuit’s interlocutory order provides early insight on the intricacies and potential strengths and weaknesses of PFAS class action litigation.  While the interlocutory order is not a final order regarding the merits of the litigation, it is clear that the Sixth Circuit will be seeking additional legal and factual support from the plaintiff to justify the district court’s certification.  A date for the merits panel hearing has not yet been scheduled.