The U.S. Environmental Protection Agency (USEPA) released its “Review of Science on Fluoride in Drinking Water: Preliminary Assessment Plan and Literature Survey.” This fast-track effort marks a critical step in Administrator Lee Zeldin’s April 2025 directive to expedite USEPA’s next fluoride health assessment under the Safe Drinking Water Act (SDWA) schedule.
The Preliminary Assessment Plan and Literature Survey outlines the transparent and systematic approach USEPA intends to follow in evaluating scientific studies of fluoride health effects. The plan describes the key science issues USEPA will consider, including sensitive populations such as infants and children, and compiles a literature survey of relevant health effects studies to be evaluated in the assessment. Releasing this plan for public comment is a critical next step in developing a new, comprehensive health assessment on fluoride in drinking water.
USEPA previously set the maximum contaminant level (MCL) for fluoride at 4.0 milligrams per liter, a standard 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 USEPA has accelerated this work to deliver updated science to the public sooner while maintaining rigorous review and quality controls.
Decisions on whether to add fluoride to drinking water are guided by public health recommendations from the Department of Health and Human Services (HHS) and the Centers for Disease Control and Prevention (CDC) and are ultimately made at the State or local level. The U.S. Public Health Service has issued Recommendations for Fluoride Concentration in Drinking Water for the Prevention of Dental Caries, otherwise known as tooth decay. The CDC’s Community Water Fluoridation Program lists the optimal level of fluoride as 0.7 milligrams per liter.
The USEPA’s new plan is available for public comment on the Federal Register through February 27, 2026.