According to the CDC: Bottled water products may contain fluoride, depending on the source of the water. Fluoride can be naturally present in the original source of water (or spring), and many public water systems add fluoride to their water...both common sources for bottlers. Bottled water products labeled as de-ionized, purified, demineralized, or distilled have been treated in such a way that they contain no or only trace amounts of Fluoride, unless they specifically list Fluoride as an added ingredient.