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Fluoride and Water Filters: Understanding effective reduction

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Fluoride and Water Filters: Understanding effective reduction

What is fluoride?

Fluorine (9F) is the 13th most abundant element in the earth's crust. Proposed as an element in 1810, fluorine exists as a highly toxic gas in its standard state, and is extremely reactive. It is not found in the atmosphere, as it reacts easily to water vapor. Instead, it is most significantly found in the minerals fluorite, fluorapatite and cryolite.1

Fluoride refers to any compound that contains the element fluorine. For example, when a mineral containing fluorine is mixed with water the hydrogen and fluorine atoms combine to yield hydrogen fluoride (HF), or hydrofluoric acid.2 This is a precursor to almost all other fluorine compounds, and is used in the production of many pharmaceuticals and polymers.3 When you hear the term “fluoride” as it relates to tap water, remember that it is a general term. The particular fluoride compound used for water fluoridation depends on the selection of local water authorities.

What is water fluoridation?

Water fluoridation is the controlled addition of a fluorine compound to a public water supply.4 The three most common compounds added to drinking water are:

  • Sodium fluoride (NaF)- A colorless, odorless crystalline solid or white powder. It is typically manufactured by the reaction of hydrofluoric acid with sodium carbonate. Sodium fluoride dissolves easily in water, and is commonly used in fluoride toothpastes, rinses and supplements.5 Other uses include: pesticides, wood preservatives, solvents, corrosion inhibitors, and glass manufacturing.6 It is one of several compounds used for municipal water fluoridation. It is more expensive than other compounds, but reportedly easier to handle in its crystalline form.7

  • Fluorosilicic (Hydrofluorosilicic) acid (H2SiF6)- An inexpensive, colorless chemical byproduct of phosphate fertilizer manufacturing. When phosphoric rock is converted to soluble fertilizer, the process creates two toxic fluoride gases: hydrogen fluoride and silicon tetrafluoride. As hydrogen fluoride condenses, it is collected, “...into storage tanks and shipped to water departments throughout the country.” Because pharmaceutical and food grade Fluorosilicic acid is prohibitively expensive, most water treatment facilities utilize industrial grade Fluorosilicic acid, which commonly contains unwanted contaminants such as arsenic and lead.

    Fluorosilicic acid is the most commonly used additive for water fluoridation in the United States.8 Unlike Sodium fluoride, “Hydrofluorosilicic acid is easily the most dangerous chemical at your local water treatment plant. It can release hydrogen fluoride when it evaporates, is corrosive, and can damage the lungs if breathed in, making it especially dangerous for plant employees if stored incorrectly.”9

  • Sodium Fluorosilicate (Na2SiF6)- A fine, white, odorless, powder made by neutralizing fluorosilicic acid with sodium chloride or sodium sulfate. It is the sodium salt of fluorosilicic acid.10 It is easier to transport than fluorosilicic acid. In addition water fluoridation, sodium fluorosilicate is used in laundry and dishwashing products, and as a rodenticide.11

Does any compound of fluorine occur naturally in water?

Calcium fluoride- As mentioned above, there are naturally-occurring minerals that contain the element fluorine.12 When the composition of soils and bedrock causes these minerals to come into contact with water, fluoride occurs naturally in drinking water. Many cities in the world do not fluoridate their water supplies because naturally-occurring calcium fluoride affects local water sources.

What does the ADA and CDC say about water fluoridation in the US?

The ADA and CDC have historically promoted the fluoridation of drinking water. However, this has become increasingly more of a controversial issue as the results of many studies, conducted both in the US and in Europe, appear to challenge the veracity of such recommendations. We suggest that readers familiarize themselves with such studies, and make up their own minds regarding water fluoridation.

What are the current drinking water standards for fluoride?

The current EPA enforceable maximum contaminant level (MCL) for fluoride in drinking water is 4.0 mg/L.13 The MCL is set to be as close as possible to the public health goal that the EPA finds may be achieved with the best use of technology, taking factors like cost into consideration.

The current EPA non-enforceable secondary standard (SMCL) for fluoride is 2.0 mg/L. Secondary standards regulate contaminants that may cause cosmetic effects (such as skin or tooth discoloration), or aesthetic effects (such as taste, odor, or color of drinking water).

According to the EPA’s Secondary Drinking Water Standards: Guidance for Nuisance Chemicals:

While SMCLs are not federally enforceable, EPA requires a special notice for exceedance of the fluoride SMCL of 2.0 mg/L. Community water systems that exceed the fluoride SMCL of 2 mg/L, but do not exceed the MCL of 4.0 mg/L for fluoride, must provide public notice to persons served no later than 12 months from the day the water system learns of the exceedance (40 CFR 141.208).14

What are the concerns and potential health risks associated with water fluoridation?

Water fluoridation in the US began in the 1940s, and has been a topic of controversy since its inception. Competing viewpoints argue whether it is a public health achievement, or an unnecessary, even dangerous, contaminant.

The US currently fluoridates over 70% of its public water supplies, making it extremely important to understand the concerns outlined below.


According to a 2013 Congressional Research Service Report for Congress15, concerns around the fluoridation of water stem in part from the increase in general fluoride exposure since The Department of Health and Human Services (HHS) issued their original, recommended water fluoridation levels in 196216:

Because the use of fluoridated dental products and the consumption of food and beverages made with fluoridated water have increased since HHS recommended optimal levels for fluoridation, many people now may be exposed to more fluoride than had been anticipated. Consequently, questions have emerged as to whether current water fluoridation practices and levels offer the most appropriate ways to provide the expected beneficial effects of fluoride while avoiding adverse effects (most commonly, tooth mottling or pitting—dental fluorosis) that may result from ingestion of too much fluoride when teeth are developing.17

Beyond fluoridated tap water, consumers may be exposed to fluorine (the element in fluoride) through:

  • Dental products
  • Some agrichemicals
    • Pesticides
    • Herbicides
    • Insecticides
  • Soil and groundwater contamination18
  • Common foods and beverages (examples)19
    • Tea
    • Seafood
    • Wine
    • Juice
    • Jellies
    • Raisins
    • Soups
    • Baby food
    • Soda
  • Bottled water (varies)
  • Pharmaceuticals
  • Consumer products made with perfluorinated compounds (PFCs)20
  • PET scans21
  • Fluoride released from industry
  • Cigarette smoke


Similar to concerns about the increasing, and oftentimes unknown, potential for widespread exposure to sources of fluoride, are concerns around an individual’s ability to personally control the use of fluoride in the treatment of tooth decay.

The International Academy of Oral Medicine and Toxicology (IAOMT) explains:

Fluoridation is a violation of the individual’s right to informed consent to medication. Within a community water supply, fluoride is being added to the water of everyone, even if some people do not want it and still others do not even know about the fluoride being added to the water or about its health risks.22

Lack of Control for Susceptible Populations

Consider that while the EPA’s MCL for fluoride in drinking water is 4.0 mg/L, the actual quantity one consumes daily, and the effect it has on the individual may vary. Water fluoridation uses a one-dose-fits-all model for treatment.

Susceptible populations with low body weights, such as infants and children, and individuals who consume increased amounts of water, such as athletes, military personnel, outdoor laborers, and those with diabetes or kidney dysfunction, can be more intensely affected by fluoride. Additionally, fluoride is also known to impact each individual differently based on allergies, nutrient deficiencies, genetic factors, and other variables.


A widely acknowledged health concern related to water fluoridation is dental fluorosis, the discoloration of tooth enamel primarily in children. This typically occurs due to a child ingesting too much fluoride toothpaste, but may also occur in areas where the fluoride levels are particularly high and potentially unregulated. Skeletal fluorosis refers to the weakening of bones, and has been observed in areas where naturally-occurring levels of calcium fluoride are dangerously high.

According to WebMD:

Fluoride is safe for most people in the amounts added to public water supplies and used in toothpastes and mouthwashes, and applied by dentists. Low doses (up to 20mg per day of elemental fluoride) of supplemental fluoride taken by mouth appear to be safe for most people. Higher doses are UNSAFE and can weaken bones and ligaments, and cause muscle weakness and nervous system problems. High doses of fluoride in children before their permanent teeth come through the gums can cause tooth discoloration.23

Beyond Fluorosis, Exposure to High Fluoride Levels a Concern

The International Academy of Oral Medicine and Toxicology (IAOMT), a non-profit originally founded in 1984 to explore the use of mercury in dentistry, discovered that high levels of fluoride (fluoride toxicity) can impact far more than just bones:

Hundreds of research articles published over the past several decades have demonstrated potential harm to humans from fluoride at various levels of exposure, including levels currently deemed as safe. Fluoride is known to impact the cardiovascular, central nervous, digestive, endocrine, immune, integumentary, renal, respiratory, and skeletal systems, and exposure to fluoride has been linked to Alzheimer’s disease, cancer, diabetes, heart disease, infertility, and many other adverse health outcomes, including fluoride toxicity.24

Literature in favor of water fluoridation explains that the recommended dose is an acceptable level. However, as already discussed, the list of potential sources of exposure to fluoride has grown dramatically in the last few decades, making it quite challenging to ensure populations are not overdosed.

This begs the question, how much fluoride are US populations really being exposed to in total? Consider that rates of dental fluorosis among children are on the rise. According to a 2010 report by the CDC entitled, Data from the National Health and Nutrition Examination Survey, 1999-2004 and the 1986-1987 National Survey of Oral Health in U.S. School Children, “In 1986-1987, 22.6% of adolescents aged 12-15 had dental fluorosis, whereas in 1999-2004, 40.7% of adolescents aged 12-15 had dental fluorosis.”25


Fluoride, which has an affinity for calcium26, primarily works to reduce tooth decay when applied topically. In other words, scrubbing fluoride toothpaste directly onto to teeth with a toothbrush is the ideal method of application.

Topical Rather than Ingested

According to an article critical of water fluoridation posted to the Scientific World Journal, and cataloged by The National Center for Biotechnology Information:

The classification of fluoride as a pollutant rather than as a nutrient or medicine is a useful starting point for analyzing the adverse effect of fluoride. No fluoride deficiency disease has ever been documented for humans. Indeed, the basis for setting an "adequate intake" of fluoride rests on the alleged ability of ingested fluoride to prevent tooth decay. However, since it is now known that the effect of fluoride is topical, the notion of an “adequate daily intake” is flawed. One of the key concerns about water fluoridation is the inability to control an individual's dose of ingested fluoride which brings into question the concept of the “optimal dose.” Since the 1980s numerous studies have identified that adults and children are exceeding these agreed limits, contributing to a rapid rise in dental fluorosis—the first sign of fluoride toxicity.27


Fluoride is difficult to remove from water once added. This means that overall, water sources are increasing in levels of fluoride. According to the IAOMT, “Harmful effects of fluoride, including species vulnerability, have been reported in an array of wild animals. Even domestic pets have been subjects of reports raising concerns about fluoride exposure, especially through their water and food.”28


Most developed nations, including all of Japan and 97% of Western Europe, do not fluoridate their water.29 Comprehensive data from the World Health Organization reports that there is no “discernible difference in tooth decay between the minority of western nations that fluoridate water, and the majority that do not.”30

Most developed nations, including Japan and 97% of western Europe, do not fluoridate their water.

How can I find out if my public water system adds fluoride to the water?

Contact your water utility supplier to find out your water is fluoridated. You can locate the name and contact information of your water utility supplier on your water bill. The EPA mandates that all community water systems provide customers with an annual report on water quality, including the fluoride content.

If you own a private well, you can get information about fluoride at

How is fluoride different from water treatment chemicals?

There are more than 40 chemical additives that can be used to treat drinking water. Fluoride is added solely for the alleged purpose of helping prevent tooth decay. Other treatment chemicals such as chlorine and chloramine are added to disinfect, reduce turbidity or prevent the corrosion of pipes. Unlike disinfectants, fluoride is far more difficult to remove from water, requiring a specialized media (and lots of it) in order to be effective.

Read Understanding Aging Water Infrastructure in the US for a discussion of pipes and the chemical additives that may be used in water treatment.

How can I reduce fluoride in my water?

As mentioned briefly above, once added to water, fluoride is very difficult to remove. There are only a few reliable methods to do so: reverse osmosis, deionization, and filtration with the correct media. The two primary media types are activated alumina and bone char. The preferred media, and de-facto worldwide standard for fluoride filtration is activated alumina.


Bone char is made by heating the bones of cattle to 600-900 degrees Fahrenheit. It ranges from black bone char, which is created at the lower end of the temperature range, to grey and white bone char, which occur at the higher end. Black bone char is the most effective at reducing fluoride while white bone char has virtually no ability to remove fluoride. Water filtration products made with bone char are less costly to manufacture than those made with activated alumina.

Berkey® Systems does not utilize bone char for two very good reasons:

  1. Performance- The efficiency of bone char at reducing fluoride drops precipitously at a certain gallon lifespan, which depends on the quantity of the media available. For a post filter our size, fluoride removal becomes negligible after less than 100 gallons.
  2. BSE Concerns- More importantly, there are certain biological concerns associated with the use bone char due to Bovine Spongiform Encephalopathy (BSE), or Mad Cow Disease. BSE prions are not destroyed by temperatures in the 600-900 degree range; and especially not at the lower end of that range.31


The most logical choice for fluoride filtration is inert, non-soluble activated alumina, which neither loses its efficiency nor carries any potential risk of BSE prion exposure. Also, because it is inert, it does not require the use of antifungals.

“Activated alumina is manufactured from aluminum hydroxide by de-hydroxylating it in a way that produces a highly porous material; this material can have a surface area significantly over 200 m²/g. The compound is used as a desiccant (to keep things dry by absorbing water from the air) and as a filter of fluoride, arsenic and selenium in drinking water. It is made of aluminum oxide (alumina; Al2O3)…It has a very high surface-area-to-weight ratio, due to the many “tunnel like pores that it has.”32

Pure Aluminum and Activated Alumina are Very Different

As a consumer, it is important to know that pure aluminum and activated alumina have vastly different characteristics. Pure aluminum is water-soluble, highly reactive, and is associated with negative health effects. By contrast activated alumina is not water-soluble, very stable (inert), and not associated with negative health effects.

Activated alumina is an inert compound of aluminum and oxygen. It is a naturally-occurring inorganic, non-toxic compound known as corundum.33 Rubies and sapphires are examples of gem-quality corundum. Activated alumina is no more toxic or water-soluble than are rubies and sapphires.

What about carbon-based filter elements?

Carbon-based filter elements look similar to (though do not necessarily perform like) Black Berkey® Purification Elements. What is critical to understand is that while most carbon-based filters will initially reduce fluoride, they typically experience a drastic decline in their effectiveness usually within the first 50 gallons or less. In order to ensure long term fluoride reduction, a separate fluoride reduction filter is required, as this provides the proper amount of media (activated alumina) and proper contact time in order for effective long term fluoride reduction to take place.


Some carbon-based filters on the market utilize carbonized bone char, and claim high levels of fluoride reduction without revealing the percent drop-off in fluoride reduction capabilities over time. Our team had an independent lab evaluate one carbon-based element, and it reduced fluoride at just 20.8% at 50 gallons, and a mere 14.3% at 100 gallons. By contrast the Berkey PF-2™ Fluoride and Arsenic Reduction Elements continued reduction at greater than 97% (see table below). Be cautious, and read on to understand how to evaluate fluoride reduction claims.

Please call 888-803-4438 to speak with a customer service representative at New Millennium Concepts, Ltd. if you have additional questions regarding how to evaluate fluoride reduction claims.


Black Berkey® Purification Elements are carbon-based elements. They remove up to 99.999% of viruses and 99.9999999% of pathogenic bacteria, while also removing or dramatically reducing trihalomethanes, inorganic minerals, heavy metals, pharmaceuticals, pesticides, VOCs, petroleum products, perfluorinated chemicals, rust, silt, sediment and even radiologicals.34

To create an effective, durable solution for fluoride reduction specifically, New Millennium Concepts, Ltd. developed Berkey PF-2™ Fluoride and Arsenic Reduction Elements. These “post filters” are used in conjunction with Black Berkey® Purification Elements, and offer:

  1. Activated alumina- A media specifically suited for fluoride reduction
  2. Proper contact time- Having a dedicated element allows for the proper amount of media and proper contact time
  3. Easy replacement- Being separate, Berkey PF-2™ Fluoride and Arsenic Reduction Elements may be swapped out as needed to ensure proper performance

Under normal contamination conditions, the media in a set of Berkey PF-2™ Fluoride and Arsenic Reduction Elements has been calculated to reduce fluoride for up to 1,000 gallons.

How do you evaluate the effectiveness of a potential fluoride filter?

Evaluate your options for a fluoride filter by asking the following:

  • What media is used for fluoride reduction?
  • Are you comfortable with that media?
  • Is there sufficient amounts of this media present to effectively reduce fluoride?
  • What is the life expectancy of the filter element with regards to fluoride?
  • Does independent lab testing demonstrate percent reduction over time / gallons?
    • What is the percent reduction at 10 gallons? 100 gallons?
    • What is the end of life, or maximum gallons for your desired reduction rate?
  • When should the filter element be changed out?


Be aware that certain contaminants, such as a high silica content or arsenic, can reduce the effectiveness of activated alumina media.


Independent lab testing reveals how Berkey PF-2™ Fluoride and Arsenic Reduction Elements perform over time. Look at the first column to see the volume tested, and the last for the % fluoride reduction. It is critical to have multiple samples in order to determine the rate of “% Reduction” drop-off, and by association, the lifespan of the element.

Flouride test results table. See full report at link below.

Under normal contamination conditions, the media in a set of Berkey PF-2™ Fluoride and Arsenic Reduction Elements has been calculated to reduce fluoride for up to 1,000 gallons.


The proprietary fluoride reduction media in the Berkey PF-2™ Fluoride and Arsenic Reduction Elements is a high yield activated alumina especially formulated for the removal of fluoride and arsenic from drinking water. This media has an unusually high surface area of more than 350 sq.m./gram of material, which allows more efficient removal of the fluoride and arsenic ions.

This high surface area is enhanced by controlled development of the pore size distribution from 30 Angstroms to 100 Angstroms, providing greater accessibility to the surface active sites through bulk diffusion. Uniform particle size, low silica content and high purity, is characteristic of the proprietary fluoride reduction media.

Sodium fluoride (NaF), sodium fluorosilicate (Na2SiF6) and calcium fluoride- The Proprietary fluoride Reduction Media will reduce all types of inorganic fluoride salts.

Fluorosilicic (Hydrofluorosilicic) acid (H2SiF6)- Testing was conducted for fluoride salts. Tests have not yet been conducted for fluorosilicic acid. However, the molecular size of fluorosilicic acid is much larger than that of fluoride salts, and fluorosilicic acid has two negative charges whereas fluoride salts only have one. The “extra” negative charge makes fluorosilicic acid easier for the media to absorb as compared to regular fluoride ions. Therefore, it is highly likely the media will perform similarly (or even better) with regards to reducing fluorosilicic acid. Nevertheless, since NMCL has no specific testing for fluorosilicic acid, we cannot make any specific claims for fluorosilicic acid reduction.


Black Berkey® Purification Elements and the Berkey PF-2™ Fluoride and Arsenic Reduction Elements are powerful, proven, durable and economical. Berkey® systems are the top choice for everyone who is considering a gravity-fed system.


(1) Fluorine
(2) Hydrogen Fluoride
(3) Hydrofluoric Acid
(4) Water Fluoridation
(5) Fluoride: Topical and Systemic Supplements
(6) Sodium Fluoride
(7) Water Fluoridation
(9) Designing Proper Hydrofluorosilicic Acid Storage
(10) Water Fluoridation
(11) Sodium Hexafluorosilicate
(12) Calcium Fluoride
(13) National Primary Drinking Water Regulations
(14) Secondary Drinking Water Standards: Guidance for Nuisance Chemicals
(15) Fluoride in Drinking Water: A Review of Fluoridation and Regulation Issues
WHO: Fluoride in Drinking-water
(16) U.S. Lowers Recommended Fluoride Levels in Drinking Water
(17) Fluoride in Drinking Water: A Review of Fluoridation and Regulation Issues
(18) Fluoride contamination on the rise in Texas groundwater
(19) USDA- Nutrient Lists
(20) IAOMT Position Paper
(21) Wikipedia- Fluorine
(22) Top Ten Reasons to Oppose Water Fluoridation
(23) WebMD: Fluoride
(24) Top Ten Reasons to Oppose Water Fluoridation
(25) Prevalence and Severity of Dental Fluorosis in the United States, 1999-2004
(26) Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride.
(27) Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention
(28) Top Ten Reasons to Oppose Water Fluoridation
(29) U.S. Public Health Service Recommendation for Fluoride Concentration in Drinking Water for the Prevention of Dental Caries
(30) Fluoride and Oral Health
(31) Bovine Spongiform Encephalopathy (BSE), or Mad Cow Disease
(32) Wikipedia- Activated alumina
(33) Wikipedia- Corundum
(34) Black Berkey® Purification Elements Test Results

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