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Consumer advocate groups are asking a federal appeals court to reconsider its decision to throw out a landmark federal court ruling that fluoride added to drinking water poses an unreasonable risk to children’s health and must be regulated.
In a petition for rehearing filed Monday, Food & Water Watch, the Fluoride Action Network (FAN), Moms Against Fluoridation and other plaintiffs urged the U.S. Court of Appeals for the 9th Circuit to reconsider its May 21 ruling.
The groups asked for a rehearing before the full court or the original three-judge panel that decided the case.
They argued that the appeals panel was wrong to set aside a ruling by the U.S. District Court for the Northern District of California. They said the panel relied on a procedural argument that the U.S. Environmental Protection Agency (EPA) raised for the first time on appeal, even though the agency had plenty of opportunities to raise the argument in the district court.
The dispute stems from a 2016 petition the groups filed with the EPA asking the agency to regulate water fluoridation under the Toxic Substances Control Act.
When the agency denied the petition, the petitioners gained the right to a fresh look at the scientific evidence in court. In this type of review, known as “de novo” judicial review, the court reaches its own conclusions without giving the agency’s judgment the weight it would have in a typical legal case.
The groups sued the EPA, which led to seven years of litigation in a two-phase trial. Presiding U.S. District Judge Edward Chen paused the case after the first phase to await a scientific review by the National Toxicology Program (NTP) of fluoride’s neurotoxic effects.
Once the NTP report became available — despite documented attempts by government officials to suppress it — the trial proceeded.
9th Circuit judges got it wrong, plaintiffs say
In 2024, Chen ruled that a preponderance of scientific evidence shows that current water fluoridation levels in the U.S. may damage human health, particularly that of pregnant mothers and young children. He directed the agency to initiate rulemaking for fluoridated water.
The verdict delivered a major blow to the EPA, public health agencies like the Centers for Disease Control and Prevention and professional lobbying groups like the American Dental Association, which have staked their reputations on the claim that water fluoridation is one of the greatest public health achievements of the 20th century and an unqualified public good.
The EPA appealed the ruling, and a three-judge panel for the 9th Circuit vacated the judgment, sending it back to the lower court.
The judges didn’t challenge the substance of the lower court’s findings — that fluoride is toxic to children and ought to be regulated. Instead, they ruled that Chen violated a law — the party-presentation principle — when he stayed the proceedings to await the outcome of the government’s NTP report.
The 9th Circuit panel directed Chen to decide the case based only on evidence presented in the first part of the trial, before the NTP report became available.
In their filing, the plaintiffs argue that the panel misapplied the party-presentation principle, which requires courts to decide cases based on issues presented by the parties, not new issues introduced by the court.
Chen didn’t introduce a new legal issue, the plaintiffs argued. He exercised his judicial authority to manage the proceedings to wait for evidence that both parties had cited as critical evidence in the first phase of the trial.
In other words, the 9th Circuit judges were wrong when they ruled that the District Court “determined on its own” that the NTP review was relevant and important to the case.
The EPA itself described the forthcoming NTP review as “indisputably central” to the case and argued that it was premature to decide on the science until the review was complete, according to the filing.
The agency raised no concerns in the second phase of the trial that pausing the trial violated the party-presentation principle. And it didn’t raise that issue until the appeal.
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Original finding that fluoridation reduces IQ ‘stands as solid as a rock’
The plaintiffs also warn that the panel’s ruling could “chill ordinary, well-accepted case-management practices in complex cases,” undermining federal judges’ longstanding authority to stay proceedings, reopen evidentiary records and consider developing scientific evidence.
They are asking the 9th Circuit to reconsider its decision, which could potentially restore the District Court’s ruling.
Commenting on the case, FAN board member Rick North said that one point continues to stand out above all the legal wrangling: “the science-based decision, finding that fluoridation ‘poses an unreasonable risk of reduced IQ in children,’ stands as solid as a rock. Neither the EPA nor the appeals court refutes that determination.”
“It would be a real shame if the ruling protecting pregnant women and their children becomes a casualty of procedural disputes,” he added. “Meanwhile, cities aren’t waiting.”
Since the lawsuit ruling in September 2024, more than 80 other communities, including two states — Utah and Florida — and several counties have voted to end water fluoridation.
“This isn’t blue vs. red,” said North. “It’s health versus harm.”
The EPA did not immediately respond to a request for comment.
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