A federal appeals court has overturned a landmark ruling that deemed current U.S. levels of water fluoridation an “unreasonable risk of injury to health or the environment” without adequate consideration of costs or non-risk factors, including potential harm to vulnerable populations. The decision initially required the Environmental Protection Agency (EPA) to address the health risks posed by fluoride in drinking water.
The 9th U.S. Circuit Court of Appeals vacated Senior U.S. District Judge Edward Chen’s ruling, finding the judge had “commandeered” the case by misusing his discretion. The panel stated that Chen improperly refused to rule on the first trial record and postponed the case for over a year to await additional evidence from a government study that was not part of the original trial proceedings.
In an unsigned opinion, the three-judge panel sent the case back to Chen in San Francisco with instructions to base his decision solely on evidence presented during the initial bench trial. “A federal court just told a judge to ignore years of fluoride safety data and travel back to 2020. The science didn’t change. The courtroom rules did,” said Mary Holland, president and general counsel at Children’s Health Defense.
Chen, a Barack Obama appointee, had ruled that water fluoridation at 0.7 mg/L presents an unreasonable risk to human health and ordered the EPA to comply with the Toxic Substances Control Act (TSCA). His decision—detailed in an 80-page ruling—stated there was “an unreasonable risk of such injury” sufficient for the EPA to take regulatory action.
On appeal, the federal government argued Chen’s approach allowed evidence beyond the initial petition to influence his ruling. Michael Connett, a partner at Siri & Glimstad representing anti-fluoride plaintiffs, criticized the EPA’s actions, noting that “Zeldin had complete discretion to stand down on the appeal and follow the court’s order to protect Americans from health risks posed by fluoridation.” Connett added that Zeldin’s decision to pursue the appeal—despite repeated pleas from advocacy groups—has now been undone by the appeals court.
The appellate ruling cited a procedural violation of the party presentation principle, which mandates that litigants—not judges—control the evidentiary record. The panel deemed Chen’s extended delay to await a multiyear government study a “very expansive and unprecedented” abuse of judicial authority, emphasizing that the judge reshaped the case’s evidence rather than adhering to the original trial framework.
The decision marks a significant reversal for water fluoridation policy, with critics arguing it nullifies a historic opportunity for the EPA to address potential neurological harm in children linked to fluoride exposure.
