Fluoride In Drinking Water

Fluoride is common in our tap water as well as in many sources of drinking water. It’s a natural mineral that exists in the earth’s upper crust and occurs naturally in surface waters and groundwater around most parts of the world.

In surface waters, fluoride occurs naturally from the weathering of rocks and soils containing fluoride compounds while in groundwater, it occurs from the leaching of bedrocks with fluoride content.

However, the fluoride in tap water is often from the additional fluoride added to the community water supply – a process called fluoridation. This is usually done in many areas of the world where there’s a low concentration of fluoride in the drinking water.

In this article, we will demonstrate the important things you need to know about fluoride in water.

Here you will find:

Fluoride in water and Water Fluoridation

Water Fluoridation

Water fluoridation is the water adjustment process that rises or reduces the natural fluoride concentration in drinking water to an optimum level that’s effective for reducing tooth decay and promoting good dental health.

It’s done to aid in both dental and skeletal health or more specifically, to reduce and prevent the prevalence of tooth damage and decay across populations.

Water fluoridation is safe and effective.

Researchers from around the world including public health and multinational scientific organizations (U.S.A, Canada, Australia, Great Britain, New Zealand, and the World Health Organization) have conducted hundreds of studies and reviews on the safety and effectiveness of adding fluoride at optimum levels used in community water.

Experts have weighed the findings as well as the quality of available scientific evidence and concluded that there’s no link between community water fluoridation and any serious unwanted health effects.

Apart from the occasional mild cases of dental fluorosis, water fluoridation is safe for both children and adults and is the most effective public health measure in preventing cavities or tooth decay.

Furthermore, water authorities around the world regularly monitor and maintain fluoride levels in community drinking water supplies at safe and effective levels.

Fluoride In Drinking Water – Safe Levels

The World Health Organization recommends that the optimum or safe fluoride level in drinking water should be:

AreaSafe LevelMaximum
Warm ClimateLess than 1mg/L1.5 mg/L
Cooler ClimatesLess than (up to) 1.2 mg/L1.5 mg/L

These WHO standards are however not universal, especially in parts of the world where the levels of fluoride might be excessive.

In the U.S, for instance, as of 2015, the Department of Health and Human Services set 0.7 mg/L to be the optimal fluoride level in public water systems for preventing tooth decay.

This is a replacement for the earlier recommended range of 0.7 to 1.2 mg/L issued in 1962.

As for Canada, the optimum recommended level of fluoride in drinking water by the government is 0.7 mg/L while the maximum acceptable concentration remains at 1.5 mg/L.

In Australia, the National Health and Medical Research Council (NHMRC) recommended a range of 0.6 to 1.1 mg/L for their community water fluoridation after conducting systematic reviews in 2007 and 2017.

Therefore, the appropriate safe range of fluoride levels in water is from 0.5 to 1.5 mg/L. It should always be kept well within this range for optimal dental health and to protect children from dental fluorosis.

Any drinking water that contains fluoride above the maximum allowable level of 1.5 mg/L can lead to fluorosis and other health problems. Anything higher than 4 mg/L could be hazardous.

How much is 0.7 mg/L of fluoride water

The Benefits Of Fluoride In Drinking Water

Reduces and Prevent Tooth Decay Among Children

Adding fluoride in community water systems to an optimum level has been found to be effective in reducing and preventing tooth damage and decay, especially in children living in areas where the fluoride levels in the drinking water are low.

The Benefits Of Fluoride In Water

Tooth decay is a common public health problem that affects children. In fact, a 2011 study carried out by the CDC shows that the rate of decayed teeth was 32% higher among children residing in non-fluoridated areas compared to those in fluoridated communities.

Studies show that fluoridated water helps reduce tooth decay by a rate of 29% among children aged 4 to 17. The fluoride in the water helps strengthen teeth and makes them more resistant to acid attacks. Moreover, it helps with repairing damage caused by early decay, slowing down, or ultimately stopping the decay process.

Fluoridated Water also Protects Adults’ Teeth

Water fluoridation also plays an important role in preventing teeth decay among adults of all ages. An analysis of several studies on the effectiveness of water fluoridation conducted by the American Dental Association (ADA) found that dental decay in adults is reduced by 27%.

The studies show that fluoride’s topical effect in an adult’s mouth can stop the decay process during the early stages and as well make the enamel surface stronger and more resistant to further acid attacks.

Other studies in Australia (2013) and also in the American Journal of Public Health (2010) demonstrated that greater exposure to fluoridated water from childhood reduces the chances of loss of teeth (as a result of decay) 40 or 50 years later.

Saves Money on Dental Treatment

Fluoridated water helps conserve the natural tooth structure hence reducing the need for fillings as well as other subsequent dental treatments. It saves money especially considering that most people around the world can’t afford the cost of having regular dental checks.

According to a report by the U.S.A Community Preventive Services Task Force, the percentage of children (aged 4 to 17) with untreated tooth decay was found to be twice high (25%) for those from low-income households compared with those from higher-income families.

Therefore, community water fluoridation is particularly beneficial not only to children but also to those on a lower income because it’s delivered directly into homes at no incremental cost. Furthermore, the task force found that the economic benefit that results from community water supply fluoridation is much great than the cost.

The Dangers Of Fluoride In Drinking Water

Can Lead to Dental Fluorosis

Dental Fluorosis due to exposure to too much fluoride

Although optimally fluoridated water has been proven safe for consumption by children, adults, and even babies, exposure to too much fluoride can result in dental fluorosis, a cosmetic condition that primarily leads to changes in the appearance of the teeth.

It usually looks like tiny white streaks or flecks on the teeth and occurs when babies take in too much fluoride while the teeth are still developing under the gums. This happens when infant formula either powdered or liquid concentrate is mixed with optimally fluoridated water.

It can be mild (barely visibly lacy white markings) or severe like pitting of the teeth. However, it doesn’t really affect how the teeth function or the child’s general health and can’t develop once teeth are fully formed.

Can Lead to Skeletal Fluorosis

Excess or chronic ingestion of fluoride can lead to skeletal fluorosis which is a bone disease that can result in pain and cause damage to bones and joints.

In this condition, fluoride accumulates in the bone continuously over many years causing the bones to become hardened and less elastic hence increasing the risk of fractures.

Early symptoms of skeletal fluorosis are stiffness and pain within the joints but in severe cases, ligaments may calcify, and also the bone structure may change resulting in pain and impairment of muscles or impaired joint mobility.

Acute Fluoride Poisoning

Over-ingestion or high-level exposure to fluoride over a short period may result in fluoride poisoning. Some of the symptoms or immediate effects of fluoride poisoning include nausea, vomiting, diarrhea, abdominal pain, excessive salivation, or increased thirst.

Muscle spasms and seizures may also occur as a result of fluoride poisoning. The symptoms start 30 minutes after ingestion and often can last up to 24 hours.

However, acute over-exposure to fluoride is very rare and it usually stems from accidental contamination of drinking water or as a result of fires or explosions. On the other hand, such acute toxic levels can’t be achieved by drinking fluoridated water.

Although there is scientific evidence that fluoride at an optimum level in drinking water is good for the teeth, excessive levels can occur in areas where a high amount of naturally occurring fluoride is detected.

In such cases, especially when alternative sources are not available, removing fluoride or defluoridation of water is not only necessary but it’s also the only effective measure to preventing fluorosis and other health problems resulting from excessive fluoride ingestion.

On the other end, while most people are content with the current recommended levels of fluoride in their water, some aren’t due to the concerns that a higher intake of fluoridated water may increase or cause other health problems.

Because of these concerns, they often try to figure out they can remove fluoride from their tap water. However, this is partly driven by unfounded “fears of ‘chemicals,’ which unfortunately have been associated with toxins or poison. It’s not actually based on sound science or scientific knowledge.

Nonetheless, there’s evidence excess ingestion of fluoride can trigger serious health problems. If you suspect your drinking water or state has higher levels of fluoride, having it reduced or removed might be more beneficial to your health.

How To Get Rid Of Fluoride In Water

The question is:

Can you remove fluoride from water?

The answer is:

Yes, it’s possible to remove fluoride from water. It’s a difficult water treatment action but there are several methods that can remove the fluoride ion although they may vary in their effectiveness.

To truly get non-fluoridated water, the fluoride ions have to be tackled at the molecular or chemical level to ensure effective elimination.

Here are several effective approaches and methods that can help remove fluoride from your drinking water.

Reverse Osmosis

Reverse osmosis filtration is a very effective method for removing fluoride as well as other contaminants from a home water supply. It can remove more than 95% of the fluorine content in water.

A reverse osmosis process uses an applied pressure to force water through a partially permeable membrane (Thin-film Composite Membrane, TFC) through which only water molecules are allowed to pass through.

Fluoride and all other contaminants including minerals, ions, unwanted molecules as well as larger particles are left behind. The end result is pure fluoride-free water.

The only issue with RO systems is that while they are able to remove fluoride, essential minerals like calcium, sodium, and iron which are beneficial to your health are also removed in the process. Including a remineralization filter can help add these minerals back into the water.

The good thing is that you can buy a RO filtration system for your home. It can be installed right under your kitchen sink to treat your drinking water before it exits the faucet. Alternatively, you can get a whole-house RO system that is installed at your home’s main water line.

Flocculation – The Nalgonda Technique 

The Nalgonda technique is an equally effective method for removing fluoride in water. It can remove more than 90% of fluoride in water. The process uses aluminum sulfate (a coagulant normally used for water treatment) to flocculate fluoride ions present in the drinking water.

Flocculation – The Nalgonda Technique

The system is made up of two 20 liter plastic buckets, each having a small brass tap fixed about 5 cm above the bottom part to enable trapping of the sludge just beneath the draw-off point.

The top bucket tap contains a tea sieve where a small piece of cotton cloth is fitted to allow the water to flow straight into the second bucket which is meant to hold the clean water.

Aluminum sulfate and lime are simultaneously added to the fluoridated water in the upper bucket where they are dissolved by stirring using a wooden paddle – lime is added since the process works best under alkaline conditions.

After a rigorous stirring, the chemical elements in the water coagulate into flocs which are heavier than water hence they settle easily to the bottom of the upper container. Thereafter, the flocs are left to settle for around one hour (not more than two hours).

During this flocculation and settling process, micro-particles, as well as negatively charged ions like fluoride, are removed through electrostatic attachment to the flocs.

Once this process is completed, the treated water is withdrawn from the top bucket through the cloth-fitted tap (safely above the sludge level) and run into the second clean water bucket below where it’s stored for drinking and cooking.

This Nalgonda technique is suitable for both household and community use. It can be done on a small or large scale.

Adsorption using Activated Alumina 

Adsorption involves filtering water down through an adsorptive media that’s packed in a column. Many adsorptions or fluoride filters use activated alumina as the primary medium for fluoride removal.

Activated alumina is aluminum oxide which is basically a porous, solid version of aluminum oxide prepared to have an adsorptive surface. It’s a strong adsorbent, a viable and highly effective medium for removing fluoride in water.

When fluoridated water passes through the column packed with activated alumina grains, fluoride, and other contaminants are effectively absorbed from the water onto the surface of the activated alumina granules.

Having a higher surface area to weight ratio, the activated alumina media has a higher capacity to absorb the fluoride. It can remove more than 90% of fluoride from water or down to around 0.1ppm which is a much safer concentration.

This method is also suitable for the community and household use. There are small filtration options available like a home filter system or water bottles that you can purchase.

However, note that for the activated alumina medium to be effective for fluoride removal, the water pH needs to be 6.5 or lower (for proper absorption to occur).


Distillation is perhaps the oldest and most affordable method for purifying water. It’s also an effective and least expensive method for removing fluoride from water.

The process works simply through evaporation and condensation. Fluoridated water is heated to a boiling point causing steam to evaporate which then condenses onto a surface upon cooling turning back into pure, distilled water. 

The now distilled water is collected into another new container thereby leaving fluoride and other contaminants behind. What you get is pure, fluoride-free water. 

Like the RO water filtration system or the activated alumina method, you can purchase a home distillation unit for convenient removal of fluoride whenever needed.

The distillation process of water distillers is slightly slow though, so it may be a more practical option for individuals or small families. You can as well try a DIY approach to distill your water at home.

Bone Charcoal

The final method for fluoride removal is using Bone Char (BC) Carbon which is another old method for removing fluoride from water. The bone char is made from finely crushed animal bones which are heated to extreme temperatures and provide in form of filter cartridges.

Same to activated alumina, bone char is a highly efficient method for removing fluoride as well as other contaminants like lead and arsenic. It consists of a very porous ionic surface which provides a very high absorption capacity that can remove up to 90% of fluoride from water.

But, again similar to activated alumina, this method too will work best when the pH level of the water is slightly acidic (lower than 6.5). The only downside is that it’s one of the methods that’s not easily accomplished at home.


The benefits of adding fluoride in water, especially in community water supplies is indeed a landmark achievement in the dental industry. Provided it’s added to the right dosage or optimal level (0.5 to 1.0 mg/L), it’s a safe and highly effective measure for preventing tooth decay.

Fluoridation of public drinking water happens nearly everywhere in the world but despite so, it’s important to keep in mind that excess ingestion of fluoride beyond the recommended levels can lead to serious health issues.

Therefore, if your home drinking water contains a high concentration of fluoride, you should take the appropriate measures to have it reduced or removed. Consider using proven effective methods like we’ve listed above to do away with the excess fluoride.

Average Fluoridation Levels in the USA


Is there fluoride in tap water

Yes, fluoride is present in tap water as optimal levels range from 0.7 mg/L – 1.5 mg/L.

Is there fluoride in bottled water?

Some bottled waters contain fluoride, and some do not. Mostly, the bottled water is treated water with fluoride is removed or the fluoride concentration is lower than the optimal levels (0.7-1.5 mg/L).


This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to be a substitute for professional advice, diagnosis, or treatment. Always seek the advice of your dentist or another qualified healthcare provider with any questions you may have regarding a medical condition or treatment.

Reference sources

  • https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6037a2.htm?s_cid=mm6037a2_x
  • https://www.thecommunityguide.org/sites/default/files/assets/OnePager-OralHealth-Community-Fluoridation.pdf
  • https://www.ncbi.nlm.nih.gov/pubmed/17452559
  • https://www.ada.org/~/media/ADA/Public%20Programs/Files/Fluoridation_Benefits_to_Adults.pdf?la=en
  • http://jdr.sagepub.com/content/92/4/376
  • https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1752-7325.2002.tb03445.x
  • https://www.thecommunityguide.org/sites/default/files/assets/OnePager-OralHealth-Community-Fluoridation.pdf
  • https://www.who.int/water_sanitation_health/diseases-risks/diseases/fluorosis/en/
  • https://www.thecommunityguide.org/sites/default/files/assets/Oral-Health-Caries-Community-Water-Fluoridation.pdf
  • http://www.health.gov.on.ca/en/common/ministry/publications/reports/fluoridation/fluoridation.aspx
  • https://www.dhhs.tas.gov.au/publichealth/water/drinking/fluoride
  • https://www.who.int/water_sanitation_health/dwq/chemicals/fluoride.pdf
  • https://www.who.int/water_sanitation_health/dwq/chemicals/fluoride.pdf
  • https://www.canada.ca/en/health-canada/services/healthy-living/your-health/environment/fluorides-human-health.html
  • https://www.nhmrc.gov.au/about-us/publications/2017-public-statement-water-fluoridation-and-human-health
  • https://apps.who.int/iris/bitstream/handle/10665/43514/9241563192_eng.pdf;jsessionid=B6D58002E724D5111659E0B3D67B205C?sequence=1
  • https://nepis.epa.gov/Adobe/PDF/P100KFZQ.pdf

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