Fluoride in Drinking Water
On January 22, 2026, the U.S. Environmental Protection Agency (EPA) announced the next step in the Agency’s new human health assessment of fluoride in drinking water by releasing the Fluoride Human Health Toxicity Assessment: Preliminary Assessment Plan and Literature Survey (pdf) for public comment.
EPA’s Preliminary Assessment Plan and Literature Survey will be available for public comment in the Federal Register in the coming days - the link for public comment will be posted on this page when it is available. EPA will host a public informational webinar on January 28, 2026 to discuss the assessment plan as well as next steps. The webinar registration link will be posted on this page shortly.
The announcement follows up on the April 7, 2025 commitment to expeditiously review new scientific information on potential health risks of fluoride in drinking water.
Background
EPA’s role under the Safe Drinking Water Act (SDWA) is to limit the amount of contaminants in drinking water provided by public water systems to protect public health. EPA previously set the maximum contaminant level (MCL) for fluoride at 4.0 milligrams per liter, a standard designed to prevent known or anticipated adverse health effects that was set in 1986 and most recently reviewed in 2024. Under normal SDWA timelines, the next comprehensive analysis of new scientific information on potential health risks of fluoride in drinking water would not be due until 2030, but EPA has accelerated this work to deliver updated science to the public sooner while maintaining rigorous review and quality controls.
Additional Resources
- Fact Sheet: Fluoride in Drinking Water: Gold Standard Science (pdf)
- Fact Sheet: Fluoride in Drinking Water Toxicity Assessment (pdf)