What FDA's Fluoride Rule Says About Kids' Toothpaste

What the rule covers

The rule is 21 CFR part 355, FDA’s monograph for “anticaries drug products for over-the-counter human use.” Its scope section says a product in a form “suitable for topical administration to the teeth” is recognized as safe and effective “if it meets each condition in this part.” Those conditions are the active ingredients it permits, how a package is sized, and what the label says.

A toothpaste is a “dentifrice” in the rule’s words, “an abrasive-containing dosage form (gel, paste, or powder) for delivering an anticaries drug to the teeth.” An anticaries drug is one “that aids in the prevention and prophylactic treatment of dental cavities.” The rule covers rinses and treatment gels too, but a tube of paste is a dentifrice, and that is the part a parent reads.

What the ppm number means

The rule permits three fluoride actives in a paste and sets each one’s concentration. Sodium fluoride, sodium monofluorophosphate, and stannous fluoride are each allowed in dentifrices “containing 850 to 1,150 ppm theoretical total fluorine,” and the rule states the percentage of each compound that lands in that range, 0.188 to 0.254 percent for sodium fluoride, for example. That band is the standard strength, and it is the strength the age-2 directions below apply to.

One higher strength exists. Sodium monofluorophosphate at 1.153 percent, in a dentifrice “containing 1,500 ppm theoretical total fluorine,” is its own entry in the rule with its own directions. The ppm figure on a tube, where a brand prints one, is naming which of these two entries the paste falls under.

The rule also caps the package. Under its packaging conditions, “due to the toxicity associated with fluoride active ingredients,” a toothpaste package “shall not contain more than 276 milligrams (mg) total fluorine.” That cap, not the brand, bounds how much paste a tube can hold.

What the age lines actually say

The directions are written into the rule word for word, and the label has to carry them under the heading “Directions.” For a standard-strength gel or paste, the direction reads: “Adults and children 2 years of age and older: Brush teeth thoroughly, preferably after each meal or at least twice a day, or as directed by a dentist or doctor. Instruct children under 6 years of age in good brushing and rinsing habits (to minimize swallowing). Supervise children as necessary until capable of using without supervision. Children under 2 years of age: Consult a dentist or doctor.”

For the 1,500 ppm paste, the direction starts later: “Adults and children 6 years of age and older,” with children under 12 to be instructed and supervised, and “Children under 6 years of age: Do not use unless directed by a dentist or doctor.” The rule adds an optional line such a product may print, that adults and children over 6 “may wish to use this extra-strength fluoride dentifrice if they reside in a nonfluoridated area or if they have a greater tendency to develop cavities.”

So the age on a kids’ tube is not the brand’s idea. It is the rule’s direction for whichever strength the tube contains, and a children’s paste at standard strength carries the same age-2 line an adult paste does.

The warning every fluoride toothpaste carries

The rule requires one warning on every fluoride paste, gel, or powder, under the heading “Warning”: “Keep out of reach of children under 6 years of age. If more than used for brushing is accidentally swallowed, get medical help or contact a Poison Control Center right away.” The rule says the first sentence is to be highlighted in bold type, and that this warning replaces the general warning statements other over-the-counter drugs carry.

That warning sits on a children’s toothpaste exactly as it sits on an adult one. The rule makes no exception for a product flavored or packaged for kids.

What the rule leaves out

Three things a parent might expect to find are not in it. The rule does not say how much paste to use; the directions say to brush thoroughly and to minimize swallowing, and stop there. It does not define a “training” or “toddler” toothpaste. And it does not cover a paste with no fluoride at all, because the rule applies to a product whose active ingredient is one of the fluoride compounds it lists. A fluoride-free paste makes no anticaries claim under this rule, sits outside it, and carries none of its required directions or warnings. That is the difference between the two kinds of tube on a kids’ shelf, and it is a difference in which rule applies, not a difference the rule itself draws.

Runlow does not yet carry product records for kids’ toothpaste, so this post names no brand. When it does, the fluoride compound, its percentage, and the directions on each tube will render from the record, the way every product fact on this site does.

Where this comes from

Every statement above is quoted or paraphrased from 21 CFR part 355, linked in the text: the scope and definitions in subpart A, the active ingredients and concentrations in section 355.10, the package size limit in section 355.20, and the labeling, warning, and directions in section 355.50. Runlow has not tested any toothpaste and makes no claim about any brand. Nothing here is dental advice; the rule’s own direction for a child under 2 is to consult a dentist or doctor, and this post goes no further than that.