Health advocates’ concerns about fluoride in drinking water will have to wait a bit longer, as the EPA and a federal judge in California consider new data about the chemical’s health risks.

U.S. District Court Judge Edward M. Chen in the Northern District of California postponed further proceedings Wednesday at the end of a two week trial over advocates’ concerns that fluoride is a neurotoxin, and that the Environmental Protection Agency should stop the decades-long practice of adding it to drinking water.

The advocacy groups, which include Food and Water Watch, the Fluoride Action Network, and Moms Against Fluoridation, petitioned the EPA to regulate the chemical in 2016. After the agency denied the petition, they sued in 2017.

Since then, new data has been published about fluoride’s health effects, and the National Academies of Science expects to publish another study later this year.

Chen suggested the plaintiffs file a new petition, or the agency reconsider the 2016 petition. Both parties took issue with that approach, and have yet to decide what action they will ultimately take.

A Path Forward

Defending their existing petition and bringing witnesses to trial has been a “massive undertaking,” said Michael Connett, a Waters Kraus & Paul attorney representing the plaintiffs. Starting a new petition could take more resources and time than the advocates have, he said.

“We would rather see EPA do something now to help begin trying to protect the public,” he said.

On the other hand, the EPA doesn’t have a mechanism under the Toxic Substances Control Act to re-review a petition it’s already denied. Even if a new petition was submitted, there’s “no way” the EPA could conduct a thorough review within the 90 days it has to review new petitions, said Debra Carfora, who represented the agency during closing arguments.

The advocates’ petition would need to meet the same “rigor and standards” the EPA follows for its own reviews, she said, which the agency uses to decide whether to set regulations for chemicals.

“We welcome the public’s help in helping EPA evaluate these chemicals, but there’s specific guidance, and interested persons should follow that guidance,” Carfora said.

The 90-day deadline is a tough one for the agency to meet, said Erik C. Baptist, partner at Wiley Rein in Washington and former deputy assistant administrator for the EPA’s chemical safety office.

“It’s a very difficult position that Congress put EPA in, given EPA’s resources,” he said.

Chen said it’s likely he’ll still rule on the case, but didn’t point the parties toward a particular strategy. “Better minds in the legal field, including yours, including all of you, should be able to figure that out,” he said.

The court will hold a status briefing for both sides via video conference Aug. 6.

‘Uncertainty and Variability’

Rather than focusing only on whether the chemical poses an “unreasonable” amount of risk—a standard the petitioners must meet before the EPA can decide whether to regulate—the court is considering whether it can decide that risk without solid proof that fluoride causes neurological effects.

That might be possible if there’s enough evidence to show that fluoride leads to other health effects, said Lynn Bergeson, managing partner of Bergeson & Campbell P.C. in Washington.

The EPA insists there is “too much uncertainty and variability” in the scientific literature to make regulatory decisions about fluoride in drinking water, Carfora said.

The U.S. Public Health Service recommends communities add fluoride to drinking water to reduce tooth decay, but the decision to fluoridate water systems rests with state and local governments, according to the EPA.

The case is Food & Water Watch Inc. v. EPA, N.D. Cal., No. 17-02162, closing arguments 6/17/20.