Utah made it official in January 2025. The state became the first in the US to ban water fluoridation by law, prohibiting public water systems from adding fluorosilicic acid (the fluoridation compound) to municipal supplies. The ban took effect in May 2025.
That’s a significant shift. But the broader picture is more complicated than headlines suggest.
What Utah’s Law Actually Does
The legislation doesn’t remove naturally occurring fluoride from groundwater. It bans the addition of fluoride compounds to public water supplies. In most Utah cities, this means fluoride levels will drop to whatever the natural background level is in local source water.
Natural background fluoride in the western US varies widely, from near zero in many Rocky Mountain sources to above 1.0 mg/L in some desert aquifers. Utah residents on fluoridated systems will see lower fluoride in their water. Residents on wells were never covered by fluoridation anyway.
What’s Being Debated at the National Level
The push isn’t just happening in Utah. In 2025 legislative sessions, at least 14 states introduced bills similar to Utah’s. Most haven’t passed. But the political momentum is real.
HHS Secretary Robert F. Kennedy Jr. made removing fluoride from public water a stated policy priority in early 2025. He directed the CDC and NIH to review existing research on fluoride and cognitive development.
The key piece of science driving the debate: a National Toxicology Program systematic review published in 2024 found “moderate confidence” of an association between fluoride exposure above 1.5 mg/L and lower IQ scores in children. That threshold, 1.5 mg/L, is twice the US recommended fluoridation level of 0.7 mg/L.
The NTP report also found “low to very low confidence” for cognitive effects at the 0.7 mg/L level. That distinction gets lost in coverage of the issue.
The Three Numbers You Need to Know
Fluoride regulation uses three separate numbers for three separate purposes.
The EPA MCL is 4.0 mg/L. This is the legally enforceable maximum for public water systems. It’s set to prevent skeletal fluorosis, a bone disease that occurs with long-term exposure to high fluoride concentrations. Natural fluoride above 4.0 mg/L is a genuine well water risk in parts of the Southwest and Appalachia.
The EPA Secondary MCL is 2.0 mg/L. Secondary MCLs are non-enforceable guidelines for aesthetic and cosmetic concerns. At 2.0 mg/L fluoride can cause dental fluorosis, a cosmetic mottling of tooth enamel. Secondary MCLs appear in your Consumer Confidence Report alongside primary MCLs.
The HHS-recommended fluoridation level is 0.7 mg/L. This is the level at which public health agencies have concluded that fluoride reduces tooth decay while minimizing fluorosis risk. It’s not a maximum or a minimum. It’s the target for intentional fluoridation.
A US water system fluoridating at 0.7 mg/L is operating at roughly one-sixth of the EPA MCL.
What the CDC Says
The CDC’s Community Preventive Services Task Force continues to recommend community water fluoridation. As of early 2026, the CDC has not changed its position based on the 2024 NTP review.
The CDC’s position: the evidence base for fluoride’s dental benefits is strong. Population-level studies consistently find lower rates of tooth decay in fluoridated communities. The cognitive concerns in the NTP review apply to exposure levels above the US-recommended concentration, not at it.
This creates a genuine policy disagreement. The NTP found reason for concern. The CDC finds the evidence insufficient to change its recommendation. Both are looking at the same literature.
What Your Water Contains Right Now
If you’re served by a US city that fluoridates, your water hasn’t changed unless your state passed legislation or your utility made an independent decision.
Your Consumer Confidence Report (CCR), which utilities mail annually or post online, includes your fluoride level. It will show both the measured level and the MCL. If your utility fluoridates, the level will be near 0.7 mg/L. If it doesn’t, the level reflects natural background.
If you’re in Utah after May 2025, your utility is not adding fluoride. The reported level in your CCR will reflect only natural background fluoride in your source water.
How to Reduce Fluoride If You Want To
Standard carbon filters, including Brita, PUR, and most refrigerator filters, don’t reduce fluoride. Their certification covers taste and odor, not fluoride.
Options that actually work: NSF/ANSI 58-certified reverse osmosis systems remove 85-96% of fluoride. They also remove lead, PFAS, and most other dissolved contaminants. Under-sink and countertop RO systems both qualify if they hold NSF 58.
Activated alumina filtration targets fluoride specifically. Some under-sink systems use this media. It requires more maintenance than carbon.
The Clearly Filtered pitcher is independently certified to remove approximately 98% of fluoride and is the only widely available pitcher that handles fluoride removal. Standard pitcher filters don’t.
If your concern is fluoride, check your CCR for your actual fluoride level first. If you’re at or below 0.7 mg/L and want to reduce further, a Clearly Filtered pitcher or NSF 58 RO system are the documented options.
Check your full fluoride contaminant profile for more on what the numbers mean at different exposure levels.