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FLUORIDE

Fluoride ion: Main Effects & Top 5

Published May 5, 2026·1min read

Fluoride ion (F⁻) is best known as the cavity-preventing mineral, but in hot springs it also contributes to gentle antibacterial skin care. Drinking quantity limits apply.

National maximum
25.1 mg/kg
@
Kusatsu Onsen
Table of Contents
  1. What is Fluoride ion?
  2. Main Effects
  3. Fluoride ion Top 5 Hot Springs

What is Fluoride ion?

Fluoride ion (F⁻) is best known as the cavity-preventing mineral, but in hot springs it also contributes to gentle antibacterial skin care. Drinking quantity limits apply.

Main Effects

  • Strengthens tooth enamel (when drinking)
  • Mild antibacterial action on skin
  • Abundant in alkaline springs

Fluoride ion Top 5 Hot Springs

Top 5 hot springs registered on this site with the highest content.

* Top 5 among onsen analysis records registered in this app

References

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