U.S. Court of Appeals overturns lower court judgement in EPA fluoride case, citing judicial overreach 

ADA applauds new court  decision, says ruling restores proper judicial process 

The ADA applauded a May 21 decision by the U.S. Court of Appeals for the Ninth Circuit to overturn a 2024 lower court judgement that had directed the Environmental Protection Agency to regulate fluoride in drinking water under the Toxic Substances Control Act. 

In its opinion, the court stated that the district court overstepped its judicial authority and “commandeered” the case by relying on a pending report that had not been presented by either party.  

“The district court abused its discretion when it refused to rule on the first trial record, despite the parties’ assertions that it should, and when it held the case in abeyance to wait for the completion of an additional study to which the parties had already stipulated not to present at trial,” according to the decision.  

The three-judge panel returned the case to the lower court for further proceedings with a narrower evidentiary record. 

“The appellate court recognized and noted that the lower court improperly overstepped its role and relied on a pending report, presented by neither party in the case was an abuse of discretion,” said ADA President Richard Rosato, D.M.D. “We strongly support the appeals court’s decision and believe that the best scientific evidence for more than 80 years consistently has demonstrated that community water fluoridation is both safe and effective.” 

Dr. Rosato also commented on the evidentiary concerns raised by the appellate court’s decision. 

“The lower court ruling relied in part on materials that were never presented to the EPA, making the decision to require additional review of fluoride standards unjustified,” he said. “We hope that the lower court takes the opportunity now to correct the record and provide reassurance to the American public, policymakers, and any doubters about the safety and value of community water fluoridation in the face of ongoing misinformation sparked by this previous court decision.” 

The ADA said the ruling could help address what it described as a misapplication of scientific evidence related to community water fluoridation and that it supports the appellate court’s decision to return the case for further review. 

In 2025, the Association successfully called for the EPA to appeal the court ruling for the agency to further regulate fluoridation. This occurred after a group of citizen petitioners sued the EPA following its denial of their petition to stop community water fluoridation and a judge ordered the EPA to “engage with a regulatory response.” The ADA also filed an amicus brief in support of the EPA’s appeal of the lower court order. In that brief, the ADA said the court did not adequately consider evidence related to oral disease reduction associated with community water fluoridation when evaluating whether fluoride presented an “unreasonable risk” under the Toxic Substances Control Act. 

The ADA has consistently maintained support for community water fluoridation at optimal levels to help prevent tooth decay and said it will continue to work with the EPA to provide the latest scientific evidence on the safety and efficacy of community water fluoridation.  

For more information on community water fluoridation and ADA advocacy, visit ADA.org/fluoride.