Federal Food and Drug Law & Municipal Water Infrastructure

The Federal Food, Drug, and Cosmetic Act’s Own Definition of “Drug” at 21 U.S.C. § 321(g)(1)(B) Classifies Every Municipal Water System Adding Fluoride to Prevent Dental Caries as an Unlicensed Drug Manufacturer Producing an Unapproved New Drug Under 21 U.S.C. § 355(a), the FDA’s Own Regulation at 21 CFR § 355.10 Classifies Sodium Fluoride as an Anticaries Active Ingredient Intended for Prevention of a Disease, the CDC Reports Approximately 209 Million Americans Receive Fluoridated Water Through Approximately 17,394 Community Water Systems, the CDC Defines Community Water Fluoridation as the Controlled Addition of a Fluoride Compound to Achieve a Concentration Optimal for Dental Caries Prevention, and the FDA Has Never Approved a Single Glass of Fluoridated Tap Water Under Section 505

Section 201(g)(1)(B) of the Federal Food, Drug, and Cosmetic Act, codified at 21 U.S.C. § 321(g)(1)(B), defines “drug” as “articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man.” 21 CFR § 355.10 defines “anticaries drug” as “a drug that aids in the prevention and prophylactic treatment of dental cavities (decay, caries),” and defines dental caries as “a disease of calcified tissues of teeth.” The CDC defines community water fluoridation as “the controlled addition of a fluoride compound to a public water supply to achieve a concentration optimal for dental caries prevention.” The CDC reports that in 2022, more than 209 million people received fluoridated water. The FDA announced in May 2025 that ingestible fluoride drug products have never been approved. The FDA has never approved fluoridated tap water.

By Julian Wexford · August 30, 2026 · 18 min read

I. The Definition

Title 21 of the United States Code contains the statutory definitions that determine the jurisdiction of the Food and Drug Administration. Section 321(g)(1), codified at 21 U.S.C. § 321(g)(1) and originally enacted as Section 201(g)(1) of the Federal Food, Drug, and Cosmetic Act of 1938, defines the term “drug” in four alternative prongs.¹

Prong A covers articles recognized in the official United States Pharmacopeia or National Formulary. Prong B, the most consequential for purposes of this investigation, covers “articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man or other animals.” Prong C covers articles, other than food, intended to affect the structure or any function of the body. Prong D covers articles intended for use as a component of any article specified in clause A, B, or C.²

The FDA restates this definition in its own regulations. Title 21 of the Code of Federal Regulations, Part 355, Subpart B, Section 355.10, titled Anticaries active ingredients, provides that the active ingredient of an anticaries product consists of sodium fluoride, stannous fluoride, or sodium monofluorophosphate when used in specified concentrations. Paragraph (c) of the same section defines “anticaries drug” as “a drug that aids in the prevention and prophylactic treatment of dental cavities (decay, caries).” Paragraph (d) defines “dental caries” as “a disease of calcified tissues of teeth characterized by demineralization of the inorganic portion and destruction of the organic matrix.”³

Dental caries is a disease. Fluoride is a drug that aids in its prevention. The statute contains no exception for drugs added to water.

II. The Addition

The Centers for Disease Control and Prevention, an agency of the Department of Health and Human Services, publishes a Scientific Statement on Community Water Fluoridation. That statement defines the practice in precise terms: “Community water fluoridation is the controlled addition of a fluoride compound to a public water supply to achieve a concentration optimal for dental caries prevention.” The CDC notes that the process began in 1945 in Grand Rapids, Michigan, and that dramatic declines in dental caries were noted among school children in Grand Rapids compared with surrounding areas.⁴

The CDC's definition contains three elements. First, there is a controlled addition. Second, the addition involves a fluoride compound. Third, the intended purpose is dental caries prevention. Each element tracks the statutory definition of drug at 21 U.S.C. § 321(g)(1)(B): an article intended for use in the prevention of disease in man.

The fluoride compounds used are sodium fluoride, fluorosilicic acid, and sodium fluorosilicate. All three dissociate in water to release fluoride ion, the same active moiety that 21 CFR § 355.10 identifies as an anticaries active ingredient. The optimal concentration, as recommended by the U.S. Public Health Service in 2015, is 0.7 milligrams per liter.⁵ The EPA's National Primary Drinking Water Regulations, codified at 40 CFR § 141.62, establish a Maximum Contaminant Level of 4.0 mg/L and a secondary MCL of 2.0 mg/L for fluoride, based on prevention of crippling skeletal fluorosis and cosmetic dental fluorosis respectively.⁶

The addition is controlled. The compound is fluoride. The purpose is prevention of disease. Under 21 U.S.C. § 321(g)(1)(B), it is a drug.

The CDC defines community water fluoridation as the controlled addition of a fluoride compound to achieve a concentration optimal for dental caries prevention. The statute defines drug as articles intended for prevention of disease.

III. The Census

Biennially, the CDC summarizes Water Fluoridation Reporting System data into National Water Fluoridation Statistics. The statistics include the estimated proportion of the U.S. population receiving fluoridated water, and the estimated proportion of people on community water systems that receive fluoridated water, both nationally and in each state.⁷

For 2022, the CDC reported: Total U.S. population, persons, 333,261,756. U.S. population on community water systems (CWS), persons, 289,330,482. U.S. population on fluoridated drinking water systems, persons, 209,135,866. Percentage of U.S. population receiving fluoridated water, 62.8 percent. Percentage of U.S. population on CWS receiving fluoridated water, 72.3 percent. Total number of CWS in United States, 51,842. Number of CWS providing fluoridated water, 17,394. Number of CWS adjusting fluoride, 5,561. Number of CWS consecutive to adjusting systems or to systems with naturally occurring fluoride at or above optimal levels, 5,749. Number of CWS with naturally occurring fluoride at or above optimal levels, 5,542.⁸

The CDC's own Fast Facts page reiterates the headline figure: “In 2022, 72.3% of the U.S. population served by community water systems–more than 209 million people–had access to fluoridated water.”⁹

Each of the 5,561 systems that adjust fluoride operates a chemical feed system that injects a fluoride compound into the finished water. Each system maintains records of dosage, flow rates, and residual concentrations. Each system employs operators licensed under state drinking water operator certification programs. Not one employs a pharmacist. Not one holds a drug manufacturing establishment registration under 21 U.S.C. § 360(b).

IV. The Approval Gap

Section 505(a) of the Federal Food, Drug, and Cosmetic Act, codified at 21 U.S.C. § 355(a), provides: “No person shall introduce or deliver for introduction into interstate commerce any new drug, unless an approval of an application filed pursuant to subsection (b) or (j) is effective with respect to such drug.”¹⁰

A “new drug” is defined at 21 U.S.C. § 321(p) as any drug the composition of which is such that such drug is not generally recognized, among experts qualified by scientific training and experience to evaluate the safety and effectiveness of drugs, as safe and effective for use under the conditions prescribed, recommended, or suggested in the labeling thereof.¹¹

The FDA's own position on ingestible fluoride confirms the absence of approval. On May 13, 2025, the FDA announced that it is initiating action to remove concentrated ingestible fluoride prescription drug products for children from the market. The press release states: “Unlike toothpaste with fluoride or fluoride rinses, these products are swallowed and ingested by infants and toddlers. They have also never been approved by the FDA.”¹²

On October 31, 2025, the FDA reiterated: “The FDA has not reviewed or approved ingestible fluoride drug products for safety, effectiveness, or quality, even though they have been used since the 1940s.”¹³ The agency noted that based on scientific evaluation, it concluded that such products should not be used in children under age 3 or by older children who are not at high risk of tooth decay, and that for the same reason fluoride may work to kill bacteria on teeth, it may also alter the gut microbiome.¹⁴

The FDA's public meeting notice on ingestible fluoride drug products notes that these products were marketed prior to 1962, and so are part of the drug efficacy study implementation (DESI) category, a decades-long process that has left many old drugs in limbo. Under DESI, panels of scientific experts were assigned to assess the efficacy of older drugs that were marketed with only evidence of safety before the efficacy requirement was added to the Act in 1962. While the FDA may have intended to ultimately approve ingestible fluoride prescription drug products as both safe and effective, the formal designation has never been achieved.¹⁵

If sodium fluoride tablets, 0.5 mg, swallowed by one child, have never been approved as safe and effective for prevention of dental caries, then sodium fluoride, 0.7 mg per liter, swallowed by 209 million people per day, has not been approved either. The FDA's searchable Drugs@FDA database contains approved applications for sodium fluoride dental rinse, 0.02 percent, and for stannous fluoride toothpaste. It contains zero approved applications for fluoridated municipal drinking water.

V. The Manufacturing

Section 510 of the Act, codified at 21 U.S.C. § 360, requires every person who owns or operates any establishment in any State engaged in the manufacture, preparation, propagation, compounding, or processing of a drug to register the establishment and to list the drugs manufactured.¹⁶ 21 CFR § 207.1 defines manufacture to include any part of the manufacture, including packaging and labeling.

A community water system that purchases fluorosilicic acid in bulk, stores it in a day tank, dilutes it, and injects it via metering pump into the finished water is engaged in the manufacture, preparation, and compounding of a drug. The finished water is packaged in the distribution system. It is labeled, under 21 CFR § 355.50, only if one accepts that the annual Consumer Confidence Report required by 42 U.S.C. § 300g-3(c)(4) constitutes labeling. That report lists fluoride concentration but does not contain the statement of identity “anticavity drug,” does not contain the indication “Aids in the prevention of dental cavities,” and does not contain the warning “Keep out of reach of children under 6 years of age” required for anticaries drug products under 21 CFR § 355.50(c).¹⁷

Under 21 U.S.C. § 352, a drug is misbranded if its labeling is false or misleading, if it fails to bear adequate directions for use, or if it fails to bear the warnings required by regulation. A glass of tap water containing 0.7 mg/L fluoride, served to a 2-year-old who weighs 12 kg and who will ingest approximately 1.5 liters per day in formula reconstituted with tap water, delivers a dose of 1.05 mg of fluoride ion per day. The FDA's recommended dose for fluoride supplements for children aged 6 months to 3 years in non-fluoridated areas is 0.25 mg per day. The tap water delivers four times that dose without a prescription, without directions, and without a child-resistant closure.

VI. The Enforcement Void

The Act provides for both civil and criminal enforcement. Under 21 U.S.C. § 331, it is a prohibited act to introduce or deliver for introduction into interstate commerce any drug that is adulterated or misbranded, or any new drug that is not approved. Under 21 U.S.C. § 333, violations are punishable by imprisonment of not more than one year, or not more than three years for a second conviction or intent to defraud.¹⁸

The FDA has sent warning letters to companies marketing fluoride-containing ingestible drug products without approval. The agency stated in 2025 that consistent with its general risk-based enforcement approach, it intends to take compliance action against companies that market unapproved fluoride-containing ingestible drug products with labeling for children under three years of age or that does not limit use to children at high risk for dental caries.¹⁹

The agency has not sent a warning letter to any of the 5,561 community water systems that adjust fluoride. It has not inspected a single water treatment plant for compliance with current good manufacturing practice under 21 CFR Part 211. It has not issued a Form FDA 483 to a municipal water operator for failure to validate the fluoride feed pump. The EPA, which does regulate public water systems under the Safe Drinking Water Act, requires monitoring of fluoride under 40 CFR § 141.23, but does not require that the fluoride added be pharmaceutical grade, be manufactured in an FDA-registered facility, or be labeled with adequate directions for use.

The aggregate daily production of unapproved new drug, calculated from CDC data, is substantial. 209,135,866 persons receiving fluoridated water, at an average direct and indirect ingestion of 1.0 liter per person per day (CDC estimates 1.2 L direct water intake per adult), yields approximately 209 million liters of drug product per day. At 0.7 mg/L, this represents approximately 146 kilograms of fluoride ion per day, or 53,290 kilograms per year, introduced into interstate commerce in the form of finished drinking water that crosses state lines via consecutive systems (5,749 consecutive systems) and via bottled water operations that use municipal source water.

VII. The Exemption That Does Not Exist

The operator may argue that fluoridated water is not a drug but a food, or that fluoride is a water additive regulated solely by the EPA under the Safe Drinking Water Act, and that FDA jurisdiction is preempted. The argument has some historical support. The FDA itself, in a 1979 Federal Register notice, stated that when fluoride is added to public drinking water, the FDA does not regulate the practice as a food or drug, but rather the EPA regulates it as a water additive. The Safe Drinking Water Act, enacted in 1974, grants EPA authority over public water systems.

The argument fails on its own terms. The Federal Food, Drug, and Cosmetic Act defines drug by intended use, not by regulatory convenience. 21 CFR § 355.10 defines sodium fluoride as an anticaries active ingredient when intended for prevention of caries. The CDC defines community water fluoridation as the controlled addition of fluoride to achieve a concentration optimal for dental caries prevention. The intended use is prevention of disease. The Act contains no provision stating that a drug ceases to be a drug when it is added to water. It contains no provision stating that a drug ceases to be a drug when 209 million people drink it.

The FDA has itself recognized the distinction. The agency regulates fluoride toothpaste as a drug under 21 CFR Part 355. It regulates fluoride rinse as a drug. It announced in 2025 that it intends to remove ingestible fluoride prescription drug products because they have never been approved. It requires that anticaries drug products bear the statement of identity “anticavity” and the indication “Aids in the prevention of dental cavities.” It does not require that fluoridated tap water bear either statement, because it has never evaluated fluoridated tap water under Section 505.

VIII. Conclusion

The evidence is internally consistent, sourced to federal statute and regulation, and confirmed by the CDC's own publications and the FDA's own press releases. Under 21 U.S.C. § 321(g)(1)(B), an article intended for use in the prevention of disease is a drug. Under 21 CFR § 355.10(c)-(d), a drug that aids in the prevention of dental cavities is an anticaries drug, and dental caries is a disease. The CDC defines community water fluoridation as the controlled addition of a fluoride compound to achieve a concentration optimal for dental caries prevention. The CDC reports that 209,135,866 Americans receive fluoridated water through 17,394 community water systems, of which 5,561 adjust fluoride. Under 21 U.S.C. § 355(a), no person shall introduce any new drug into interstate commerce without an approved application. The FDA stated in 2025 that it has not reviewed or approved ingestible fluoride drug products for safety, effectiveness, or quality, even though they have been used since the 1940s.

Every municipal water system that adds fluoride to prevent dental caries is manufacturing a drug that has never been approved. Every faucet that dispenses it is dispensing an unapproved new drug. Every glass of water that is swallowed for its anticavity effect is an ingestion of a drug that the FDA has explicitly stated has never been approved for ingestion in children under three or in older children not at high risk, a population that includes approximately 73 million American children who drink fluoridated tap water every day.

The FDA regulates fluoride toothpaste. It regulates fluoride rinse. It intends to remove fluoride tablets. It does not regulate the 53 metric tons of fluoride ion per year that 5,561 municipal plants add to 209 million Americans' drinking water to prevent a disease, because under the agency's own historical practice, it does not regulate public drinking water. But under the agency's own statutory definition, it already does.

Ergo.