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Shortlist

Contaminant

Fluoride in drinking water

Added for dental health. Some choose to reduce it, and it runs naturally high in a few areas.

This page can’t tell you what’s in your tap water.
Only a test of water from your own tap can. Public-system results describe the system, not your home.
7 sources
01Check your water systemWater Check · system results, not your tap02Test your tapHow to get a reliable result03Treatment approachesWhat can reduce it at the tap
On this page · 10 sections
  1. 01Reference values
  2. 02Is it in my water?
  3. 03Where it comes from
  4. 04Testing
  5. 05Water filters
  6. 06Treatment
  7. 07Evidence
  8. 08Next steps
  9. 09Ask about fluoride
  10. 10References
Reference values

An enforceable limit for public water systems.

Each value says what kind of reference it is, and they mean different things. A lower or missing number never means water is safe.

Enforceable limit · MCLFederal · public water systems
4 ppm

The highest level allowed in water a public system delivers. A legal limit, not a health goal.

Applies to
Water delivered by public water systems, not private wells
Status
In force
Source
EPA NPDWR MCL (4.0 mg/L) · 40 CFR §141.62
Health-based goal · MCLGFederal · not enforceable
4 ppm

The level below which no known health risk is expected. A goal, not a limit.

Applies to
Set alongside the rule as a public-health goal
Status
Published goal
Source
EPA National Primary Drinking Water Regulations — MCLG 4.0 mg/L · 40 CFR §141.51
Your stateNot held yetStates may set their own references. We don’t hold a state reference for fluoride yet.
Is it in my water?

Only a test of your own tap can tell.

Choose what you have. We’ll show what it can and can’t tell you.

If you haven’t tested
Nobody can tell without a measurement, including us.

Three things you can do, in this order.

Test water from your tapThis is the only way to know your level. Testing guidance ↓See what your system reportsSystem results aren’t a tap measurement. Open Water Check →On a private well?Public-system reports don’t cover wells. Open Well Water →
Where it comes from

Where it comes from

  1. Fluoride occurs naturally in groundwaters, with concentrations varying by rock type and sometimes exceeding 10 mg/L in areas rich in fluoride-containing minerals.
  2. Fluoride is added to drinking water in some countries at concentrations between 0.5 and 1 mg/L for dental caries prevention.
  3. Fluoride is present in food, vegetation, and tea, and exposure varies by region based on water concentration and other sources.
Why it matters
Mild dental fluorosis may occur at drinking-water concentrations between 0.9 and 1.2 mg/L depending on total fluoride intake from all sources.
Low concentrations of fluoride provide protection against dental caries in both children and adults, with protective effects increasing up to about 2 mg/L. · Skeletal fluorosis with adverse changes in bone structure may be observed when drinking-water contains 3–6 mg/L, particularly with high water consumption. · Crippling skeletal fluorosis usually develops only where drinking-water contains over 10 mg/L.
Testing

How to test your tap water for fluoride

Fluoride is typically determined by means of an ion-selective electrode, which can detect fluoride concentrations in water well below the guideline value.

  1. 01Use a certified labA state-certified lab, or a kit that sends samples to one.
  2. 02Follow the sampling stepsHow and when you collect the water changes the result.
  3. 03Check the reportIt should state units and the detection limit.
Certified labNot sponsored
Use a state-certified labYour state keeps a list of labs certified for drinking water.

Choosing a filter for fluoride

None qualify
No products currently qualify for a fluoride pick here.

Nothing in our database has a fluoride claim for an exact configuration we can verify.

Find a fit in FinderRead treatment approaches
Treatment

How to reduce fluoride in water

Function: ReduceRemoving fluoride requires a treatment process designed specifically for this ion, as it is not removed by standard water treatment methods.
Reverse osmosisReverse osmosis can remove fluoride as part of its capability to reduce inorganic substances in water.Before you chooseClaims apply to the exact model and configuration tested.
Activated aluminaActivated alumina is an established treatment method capable of achieving 1 mg/L or lower fluoride levels and is relatively simple to install as a point-of-use filter.Before you chooseClaims apply to the exact model and configuration tested.
Ion exchangeIon exchange is a non-conventional treatment option available for fluoride removal in water supplies.Before you chooseClaims apply to the exact model and configuration tested.
Whole-house systems and point-of-use filters treat different water. A whole-house system treats water where it enters the home; a point-of-use filter treats the tap it’s installed on. Check which one a claim is for.
Evidence

What the evidence means

We keep evidence types apart. A result for one configuration never stands in for another, and we never average across types.

No product in our database holds a reduction record for fluoride yet.

How we read evidence →

Next steps

Take the next step

Match a system to your homeFinder asks about your home first. It suggests fluoride as a starting point, and nothing counts until you confirm it.
Ask about fluoride

Still have a question?

Answers come only from WaterDecoder’s reviewed sources and show citations. Ask can’t interpret your test result or choose a product. Don’t include personal details.

AI assistant

Ask about Fluoride

Answers draw on cited public-health sources and the filters certified to reduce Fluoride. Every source is linked, and if the sources don’t cover a question, the answer says so.

Questions to start with

Educational information from cited sources. Not medical or professional advice.

References

Where these facts come from

  1. 1Regulatory reference40 CFR §141.62EPA NPDWR MCL (4.0 mg/L)
  2. 2Regulatory reference40 CFR §141.51EPA National Primary Drinking Water Regulations — MCLG 4.0 mg/L
  3. 3Knowledge BaseSecondary Drinking Water Standards: Guidance for Nuisance ChemicalsU.S. EPA
  4. 4Knowledge BaseAbout FluorideCDC
  5. 5Knowledge BaseFluoride in Drinking-water (Chemical Fact Sheet, Guidelines for Drinking-water Quality)World Health Organization
  6. 6Knowledge BaseToxicological Profile for Fluorides, Hydrogen Fluoride, and FluorineATSDR (Agency for Toxic Substances and Disease Registry) / CDC
  7. 7Knowledge BaseOverview of Drinking Water Treatment TechnologiesUS EPA (SDWA program)

Written and maintained by WaterDecoder. A review date appears only once we have confirmed one.

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