A federal appeals court has vacated a landmark ruling that said water fluoridation at current U.S. levels presents an “unreasonable risk of injury to health or the environment, without consideration of costs or other non-risk factors, including an unreasonable risk to a potentially exposed or susceptible subpopulation under the conditions of use.”
Could Water Fluoridation Be Ended After Landmark Court Decision?
The ruling had ordered the Environmental Protection Agency (EPA) to address the health risks of fluoride in drinking water.
However, the 9th U.S. Circuit Court of Appeals found the district judge had “commandeered” the case and abused his discretion by refusing to rule on the first trial record.
“In an unsigned opinion, the three-judge panel vacated Senior U.S. District Judge Edward Chen’s ruling and sent the case back to him in San Francisco with instructions to rule on the dispute based on the evidence presented at a first bench trial rather than on additional evidence that the judge decided to include on his own accord to conduct a second bench trial,” Courthouse News Service stated.
“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.
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. @CHDTVLive @ChildrensHD @BrianHookerPhD
For the complete Defender story: https://t.co/7MS3sTzBBs pic.twitter.com/AqGPzaWEX3
— Mary S. Holland, Esq. (@maryhollandnyc) May 22, 2026
More from Courthouse News Service:
Chen, a Barack Obama appointee, had agreed with a plaintiff consortium of organizations and individuals concerned that the addition of fluoride to drinking water at a concentration of 0.7 mg/L presents an unreasonable risk to human health. He had ordered the EPA to rely on guidance of the Toxic Substances Control Act to determine the safety of artificially fluoridated drinking water.
“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,” the panel said.
As such, the panel agreed with the EPA that the judge violated the so-called party presentation principle, which holds that the litigants, rather than the judge, are in charge of framing their dispute and developing the evidentiary record.
Food & Water Watch — joined by other opponents of water fluoridation, like Moms Against Fluoridation and several individuals — sued the EPA in 2017, challenging the agency’s rejection of their petition to consider whether drinking fluoride is dangerous to human health, eventually leading to Chen ordering the EPA initiate rulemaking on the chemical.
“It should be noted that this finding does not conclude with certainty that fluoridated water is injurious to public health,” Chen said in his 80-page ruling, but, “there is an unreasonable risk of such injury, a risk sufficient to require the EPA to engage with a regulatory response.”
On appeal, the federal government argued Chen’s decision meant that the case would be decided not merely on evidence presented in the nonprofit’s petition, but on evidence submitted later and scientific studies peer reviewed afterward.
“The EPA claims to want to Make America Healthy Again. It had an opportunity to do just that on the fluoride issue. In the fall of 2024, a federal district court found (after hearing extensive expert testimony) that adding fluoride to water poses an unreasonable risk of neurological harm in children, and ordered EPA to eliminate this risk. In the final days of the Biden administration, the EPA announced (as expected) its intention to appeal this landmark decision. This announcement, however, had no binding effect on Lee Zeldin and the new administration,” said Michael Connett, a partner at Siri & Glimstad representing the anti-fluoride plaintiffs.
“Zeldin had complete discretion to stand down on the appeal, and to follow the court’s order to protect Americans from the health risks posed by fluoridation. Zeldin, however, chose to continue with the appeal. Despite repeated pleas from the MAHA community, Zeldin and the EPA have persisted with its odious appeal. And now, based on a procedural technicality, a federal appeals court has granted Zeldin’s request to vacate the district court’s order,” Connett continued.
“EPA has thus officially undone a historic opportunity to protect the public from a toxic chemical added to most American water supplies (and all beverages and foods made with the water). There are many ways to describe EPA’s conduct here, but Making America Healthy Again is not one of them,” he added.
The EPA claims to want to Make America Healthy Again.
It had an opportunity to do just that on the fluoride issue. In the fall of 2024, a federal district court found (after hearing extensive expert testimony) that adding fluoride to water poses an unreasonable risk of… https://t.co/z7yk0oRqQ1
— Michael Connett (@michaelpconnett) May 22, 2026
The Defender explained further:
Connett said the decision was “a very expansive and unprecedented application of the party presentation principle.” He said that to date, “this principle has really only been applied to situations where judges raise new legal issues, not where judges use procedural mechanisms to resolve the issues presented.”
Under the TSCA, if the EPA denies a citizen petition, petitioners have the right to sue the agency. The law is unique because it specifies that the court then evaluates whether the chemical in question presents an unreasonable risk to health or the environment in a “de novo” proceeding, during which it evaluates evidence presented by both sides and gives no deference to the agency.
Rather than ruling after the first trial in 2020, Chen put the trial on hold, pending the release of a multiyear government study into fluoride’s neurotoxic effects, so he could base his decision on all available evidence.
Once that study was released — despite government officials’ attempts to suppress it, which were revealed through Freedom of Information Act requests — the second trial continued and Chen issued his ruling in an 80-page decision detailing the evidence supporting his decision.
The appellate court didn’t comment on plaintiffs’ arguments that TSCA allows this type of judicial procedural discretion, nor did it engage the substance of Chen’s findings.
Instead, in an eight-page decision, the 9th Circuit panel affirmed the EPA’s argument that Chen improperly paused the case for more than a year to await that study, which was not yet available during the first trial. The court concluded that the judge effectively reshaped the evidentiary record, exceeding the proper judicial role.
FAN board member Rick North told The Defender the judgment is a disappointment.
