Why Is Fluoride in Drinking Water?
The CDC says community water fluoridation is the process of adjusting the amount of fluoride in drinking water to a level recommended for preventing cavities. In April 2015, HHS set the recommended level at a single 0.7 milligrams per liter, replacing the range of 0.7 to 1.2 milligrams per liter issued in 1962.
There is also a legal ceiling. The EPA's maximum contaminant level for fluoride is 4.0 mg/L, and its secondary standard is 2.0 mg/L, which is not federally enforceable, though community water systems above 2 mg/L that do not exceed 4.0 mg/L must notify the people they serve within 12 months. Looking at adults, the National Toxicology Program's final 2024 fluoride monograph found no evidence that fluoride exposure had adverse effects on adult cognition.
Policy is shifting. On August 3, 2026, the EPA announced the next step in its review of public health risks linked to fluoride in drinking water, the release of a protocol for developing its fluoride human health toxicity assessment. In Utah, H.B. 81, which took effect May 7, 2025, says a person may not add fluoride to water in, or water that will be introduced into, a public water system.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Government sourceThe CDC says community water fluoridation is the process of adjusting the amount of fluoride in drinking water to a level recommended for preventing cavities. CDC ↗
- Government sourceOn April 27, 2015, HHS released its final recommendation of a single 0.7 milligrams of fluoride per liter of drinking water, replacing the 0.7 to 1.2 milligrams per liter range issued in 1962. US Department of Health and Human Services, via web.archive.org ↗
- Regulatory filingThe EPA says its fluoride maximum contaminant level is 4.0 mg/L and its non-enforceable secondary standard is 2.0 mg/L, and that systems exceeding 2 mg/L must give public notice within 12 months. US EPA ↗
- StudyThe National Toxicology Program's final fluoride monograph found no evidence that fluoride exposure had adverse effects on adult cognition. National Toxicology Program, NIEHS ↗
- Regulatory filingOn August 3, 2026, the EPA announced the release of its Protocol for Developing the Fluoride Human Health Toxicity Assessment as the next step in reviewing fluoride risks in drinking water. US EPA ↗
- Regulatory filingUtah's H.B. 81, effective May 7, 2025, says a person may not add fluoride to water in, or water that will be introduced into, a public water system. Utah State Legislature, H.B. 81 (2025) ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.