No. Boiling does not remove fluoride. When water boils, some of it turns to steam and escapes, but fluoride doesn't evaporate with it. What's left in the kettle has the same fluoride in slightly less water, so it's slightly more concentrated.
US health agency ATSDR states it plainly: "heating or boiling water does not remove fluoride." The exception is distillation, which boils water and then collects the steam, leaving fluoride behind in the boiler.
How much more concentrated?
For a normal kettle boil, not much. We haven't found a reliable government or peer-reviewed figure for typical household boiling, so we won't invent one. Water that boils for a long time, or is repeatedly reboiled, loses more volume and concentrates more.
What does remove fluoride
- Reverse osmosis (RO). The most common home option. Results vary: one peer-reviewed study of household RO units found average fluoride removal of 63.7%, ranging from 2% to 100% depending on the unit and its condition. Look for certification to NSF/ANSI 58 with a fluoride reduction claim.
- Distillation. Removes most fluoride. Slow and uses power. Certified under NSF/ANSI 62.
- Activated alumina. Targets fluoride, works best in slightly acidic water (around pH 5 to 7).
- Bone char. Absorbs fluoride; performance drops in water with high carbonate.
What doesn't
- Boiling.
- Freezing.
- Standard carbon jug filters. Brita Australia says its cartridges "are not designed to remove fluoride."
What about baby formula?
Victoria's health department says it is safe to make infant formula with fluoridated tap water. If you'd rather avoid fluoride for formula, use plain bottled water without added fluoride (it must be labelled if fluoride is added), not mineral or sparkling water, which FSANZ says isn't suitable for formula. Boil it first as usual for safety; boiling doesn't add or remove fluoride in a meaningful way.