How to Remove Fluoride from Water

Posted by
John Woodard on November 29, 2021
Fluoride was first added to a city’s water supply in 1945 in Grand Rapids, Michigan. As a result, the rate of cavities in school children fell by nearly 60 percent. Water fluoridation then became widespread as a means to improve communities’ oral health, and today about 75 percent of homes in the United States receive fluoridated water. While fluoride is undoubtedly good for oral health, there is growing controversy over the practice of community water fluoridation due to potential adverse side effects of excessive fluoride intake. Below you will learn about the benefits and risks of fluoride, how to find out if your water is fluoridated, and how to remove fluoride from your water if you choose to do so.

What is fluoride?

Fluoride is a compound of the element fluorine and is a naturally occurring mineral found in teeth, bones, water, rocks, and soil. Fluoride is commonly used in dentistry to strengthen enamel (the outer layer of your teeth) and to prevent cavities.

Why is fluoride added to water?

Fluoride is added to water because it is effective in preventing cavities and in helping to improve and maintain oral health. Almost all water contains naturally occurring fluoride, but usually at levels too low to prevent tooth decay, so many municipalities adjust the fluoride concentration in the water supply to about 0.7 milligrams per liter. 0.7 mg/L is the optimal level of fluoride in drinking water to prevent tooth decay in both children and adults, according to the Centers for Disease Control (CDC).

Community water fluoridation began after scientists found that people who lived in areas where fluoride was naturally prevalent in water had fewer cavities. When fluoride was purposefully added to the water supply in Grand Rapids, Michigan in 1945 it was an experiment of sorts, but proved so successful in improving the community’s oral health, that water fluoridation became the norm shortly after. Today, about 75 percent of homes in the United States receive fluoridated water.



What are safe levels of fluoride in drinking water?

4.0 mg/L and lower are safe levels of fluoride in drinking water, according to the Environmental Protection Agency (EPA). The EPA set 4.0 mg/L as the Maximum Contaminant Level for fluoride in drinking water provided by public water systems. However, the recommend amount of fluoride in water is much lower at 0.7 mg/L. Levels higher than 0.7 mg/L increase the risk of dental fluorosis in children (a cosmetic condition characterized by stained or discolored teeth).

What are the side effects of fluoride in water?

The side effects of fluoride in water can be both positive and negative. However, keep in mind that adverse health effects are highly unlikely to occur because of community water fluoridation, as the amount of fluoride in public water systems is too low. According to the CDC, the safety and effectiveness of community water fluoridation continues to be supported by scientific evidence and does not result in any unwanted health effect other than dental fluorosis.

Although, certain areas of the world, including large parts of Asia and Africa, have large geologic deposits of fluoride that can contaminate water supplies. Also, although rare, a person can be exposed to dangerous amounts of fluoride through industrial chemicals. Instances such as these can lead to excessive fluoride intake and may be linked to the health risks listed below.

Benefits of fluoride in water:

    • Fewer and less severe cavities
    • Rebuilds weakened tooth enamel
    • Reverses early signs of tooth decay
    • Prevents the growth of harmful oral bacteria
    • Less need for fillings and tooth extractions

Risks of fluoride in water:

    • Dental fluorosis: A cosmetic condition characterized by stained, discolored teeth because of excessive fluoride exposure in children and infants.
    • Skeletal fluorosis: When high levels of fluoride accumulate in bones, it may result in joint pain, muscle impairment, and stiffness.
    • Hypothyroidism: Under-active thyroid that may cause fatigue, increased sensitivity to cold, dry skin, and weight gain.
    • Reduced IQ

How to remove fluoride from drinking water

Fluoride can be removed from drinking water through reverse osmosis, distillation, activated alumina filters, and bone char carbon filters.

Reverse osmosis

Reverse osmosis uses pressure to push unfiltered water through a semipermeable membrane. Water particles are small enough to pass through the membrane’s tiny pores, but contaminants, such as fluoride, become trapped. Only clean, filtered water emerges on the other side.

Learn More: What is a Reverse Osmosis System and How Does It Work? | 5 of the Best Reverse Osmosis Systems



Distillation is a water treatment method that mimics how water is purified in nature: through evaporation in the atmosphere. Water distillers convert water into steam, eliminating fluoride and other contaminants because they cannot take on a gaseous form as water can. Once the water returns to its liquid form, it is contaminant free.

Learn More: What is a Water Distiller and How Does It Work? | What is Distilled Water and Is It Safe to Drink?  

Activated alumina filters

Activated alumina is a porous, solid form of aluminum oxide. When water passes through an activated alumina filter, fluoride and other contaminants are adsorbed by activated alumina granules, allowing clean water to flow to the other side. However, activated alumina filters only work in water with a pH of less than 8.5 and are most effective at removing fluoride from water with a pH between 5 and 6. Additionally, they require a lot of contact time to be effective, so water flow rates have to be very slow.

Bone char carbon filters

Bone char carbon filters are one of the oldest methods to remove fluoride from water. Standard activated carbon filters do not remove fluoride, but bone char filters are made using a careful process that enhances the adsorption abilities of carbon: heating animal bones to extreme temperatures. When water runs through a bone char carbon filter, fluoride is captured or altered by adsorption, and clean water emerges on the other side. Bone char filters can even remove heavy metals, including lead, and chlorine.

Learn More: Activated Carbon Filters 101 | How to Remove Lead from Water


Does boiling water remove fluoride?

No, boiling water does not remove fluoride. Since some water evaporates during the boiling process, fluoride concentrations will instead increase.

Do Brita filters remove fluoride?

No, Brita filters do not remove fluoride. Brita filters are not effective against fluoride and will not lower the fluoride levels in your water.

Is your water fluoridated?

You can find out if your water is fluoridated by checking with your municipal water supplier or through the CDC’s online My Water's Fluoride tool. Not every city in the U.S. fluoridates its drinking water. The decision is made by each city, but both your municipal water supplier and the CDC’s online tool can tell you whether your water is fluoridated, and if yes, how much fluoride is added.

Is fluoride in bottled water?

Fluoride may be in bottled water. It depends on the brand and the original water source of the bottled water you choose. Fluoride may be naturally present in the original water source or may be added by a municipality. Many bottled waters are filled from municipal water supplies, so if the municipality fluoridates its water, the bottled water may be fluoridated too. However, fluoride will only appear on the label if it was added during the bottling process, so we recommend checking with the brand you like to find out if it contains fluoride.


If you have any further questions about water fluoridation or how to remove fluoride from your water, please don’t hesitate to contact us.

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