The U.S. Environmental Protection Agency (EPA) has announced the next step in an accelerated federal review of potential public health risks associated with fluoride in drinking water, releasing a new scientific roadmap that will guide its forthcoming assessment under the Safe Drinking Water Act.
The agency recently published the Review of Science on Fluoride in Drinking Water: Preliminary Assessment Plan and Literature Survey, outlining how EPA scientists intend to evaluate emerging research on fluoride exposure, with particular attention to outcomes related to childhood development, as well as maternal and infant health.
The fast-tracked effort follows an April 2025 directive from EPA Administrator Lee Zeldin to expedite the agency’s next fluoride health assessment, which would not normally be required until 2030 under standard Safe Drinking Water Act timelines.
“Every American should be able to count on safe, healthy drinking water when they pour a glass to drink or use it to cook a meal, especially for a child,” Zeldin said in an EPA update about the review.
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Utah and Florida became the first U.S. states to pass laws in 2025 banning the addition of fluoride to public water. Over the last year, 14 other states pursued similar legislation. Although several bills failed to pass, some states still have bans under consideration.
EPA officials emphasized that the review will follow what the agency called “gold-standard scientific methods,” incorporating peer review, inter-agency collaboration and public transparency. The newly released assessment plan compiles key studies to be examined and identifies sensitive populations — including infants and children — as a focus of the evaluation.
The agency said the review will inform any future decisions on whether federal drinking water regulations should be revised, while noting that it is not approaching the process with predetermined conclusions.
EPA currently sets a maximum contaminant level for fluoride at 4.0 milligrams per litre, a standard established in 1986 and most recently reviewed in 2024. Separately, CDC guidance recommends an optimal level of 0.7 milligrams per litre to help prevent tooth decay. Decisions about whether fluoride is added to public water supplies, however, remain largely under state and local jurisdiction.
While federal standards apply regardless of whether fluoride occurs naturally or is intentionally added, EPA stressed that its role is limited to ensuring levels remain within health-protective limits, not directing municipalities to fluoridate.
Fluoride policy has also been shifting beyond the U.S. In Canada, the City of Montreal ceased fluoridation at the Pointe-Claire and Dorval water treatment plants in late 2024, affecting more than 143,000 residents in several suburban communities. City officials cited the need for consistency, as fluoridation does not occur elsewhere on the island, as well as technical challenges in safely managing the additive.
Regina also revisited its fluoridation program after a newly elected councillor raised concerns tied to emerging research.
Health Canada continues to recommend 0.7 milligrams per litre as the optimal fluoride concentration in drinking water.
EPA’s Preliminary Assessment Plan will be open for public comment for 30 days, marking the beginning of what the agency says will be a comprehensive and transparent reassessment of fluoride’s health impacts in drinking water.
