Actually, that’s complicated as the FDA doesn’t require fluoride to be on all the bottled water that contains fluoride naturally. However, fluoride added bottled water has to say so.
The FDA regulates bottled water. But it’s almost impossible to know how much fluoride is in the bottle, unless you call the manufacturer, because:
— Domestic bottled water with no added fluoride may contain between 1.4 and 2.4 mg/L fluoride
— Imported bottled water with no added fluoride may not contain fluoride in excess of 1.4 mg/L.
— Domestic bottled water with added fluoride can contain between 0.8 and 1.7 mg/L fluoride
— Imported bottled water with added fluoride may not contain more than 0.8 mg/L fluoride.
Bottlers are not required to list any naturally-occurring fluoride on the labels.
Fluoride can be removed from a water supply with anionic resin in a home water softener (replacing the fluoride ions with chloride ions which came from the recharging brine).
If I were king, the only human consumable things fluoride would be added to would be toothpaste and prescription drug products.