Fluoride Action Network

Frequently asked

For information on how you can remove fluoride from your water and reduce your fluoride intake from other sources, see our “Top Ten Ways to Reduce Fluoride Exposureand “Grocery Store Guide.”

Why Is Fluoride Added to Water?

Fluoride is added to water to prevent cavities (tooth decay), a non-waterborne disease.

What Makes Fluoride Different from Other Water Treatment Chemicals?

All water treatment chemicals, with the exception of fluoride, are added to make drinking water safe and pleasant to consume. Fluoride is the only chemical added to treat people who consume the water, rather than the water itself. Fluoridating water supplies can thus fairly be described as a form of mass medication, which is why most European countries have rejected the practice.

Do we need fluoride?

No. It is now well established that fluoride is not an essential nutrient. This means that no human disease – including tooth decay – will result from a “deficiency” of fluoride. Fluoridating water supplies is therefore different than adding iodine to salt. Unlike fluoride, iodine is an essential nutrient (the body needs iodine to ensure the proper functioning of the thyroid gland). No such necessity exists for fluoride.

What Countries Fluoridate Their Water?

Most developed nations in the world have rejected fluoridation, including 97% of western Europe. The United States, which fluoridates more than 70% of its water supplies, is an exception to this rule. According to the British Fluoridation Society, there are more people drinking artificially fluoridated water in the United States than all other countries combined.

Does Fluoride Occur Naturally in Water?

As a general rule, the only fresh water with high levels of fluoride (other than waters polluted by fluoride-emitting industries) is water derived from deep wells. Rather than being something to celebrate, high levels of naturally occurring fluorides have wreaked havoc on tens of millions of people’s health around the world. People consuming water with naturally high levels of fluoride have been found to suffer serious health ailments including disfiguring tooth damagebone diseaseulcersreduced IQthyroid disease, and infertility. Because of this, international organizations like UNICEF assist developing nations in finding ways of removing fluoride from the water.

Thankfully, most fresh water supplies contain very low levels of fluoride. The average level of fluoride in unpolluted fresh water is less than 0.1 ppm, which is about 10 times less than the levels added to water in fluoridation programs (0.7 to 1.2 ppm).  The frequent claim, therefore, that “nature thought of fluoridation first” does not withstand scrutiny.

Where Does the Fluoride Added to Water Come from?

The main chemicals used to fluoridate drinking water are known as “silicofluorides” (i.e., hydrofluorosilicic acid and sodium fluorosilicate). Silicofluorides are not pharmaceutical-grade fluoride products; they are unprocessed industrial by-products of the phosphate fertilizer industry. Since these silicofluorides undergo no purification procedures, they can contain elevated levels of arsenic — moreso than any other water treatment chemical. In addition, recent research suggests that the addition of silicofluorides to water is a risk factor for elevated lead exposure, particularly among residents who live in homes with old pipes.

Does fluoridated water reduce tooth decay?

If water fluoridation has a benefit, it is a minimal one. Recent large-scale studies from the United States have found little practical or statistical difference in tooth decay rates among children living in fluoridated versus non-fluoridated areas. In addition, data complied by the World Health Organization (WHO) shows that tooth decay rates have declined just as rapidly in non-fluoridated western countries as they have in fluoridated western countries. Read more.

Does Fluoride Need to Be Swallowed in Order to Prevent Tooth Decay?

NO. Although fluoridation of water was initially approved on the premise that swallowing fluoride is the most effective way to strengthen teeth, most dental researchers now concede that fluoride’s primary benefit comes from direct topical contact with the teeth, not from ingestion. There is no need to swallow fluoride to prevent tooth decay, whether in water or tablet form.

It is hard to overstate the importance of this point to the fluoride debate, particularly when considering that fluoride’s risks come primarily from ingestion.

What Are the Risks from Swallowing Fluoride?

Fluoride has long been known to be a very toxic substance. This is why, like arsenic, fluoride has been used in pesticides and rodenticides (to kill rats, insects, etc). It is also why the Food and Drug Administration (FDA) now requires that all fluoride toothpaste sold in the U.S. carry a poison warning that instructs users to contact the poison control center if they swallow more than used for brushing.

Excessive fluoride exposure is well known to cause a painful bone disease (skeletal fluorosis), as well as a discoloration of the teeth known as dental fluorosis. Excessive fluoride exposure has also been linked to a range of other chronic ailments including arthritisbone fragilitydental fluorosisglucose intolerancegastrointestinal distressthyroid disease, and possibly cardiovascular disease and certain types of cancer.

While the lowest doses that cause some of these effects are not yet well defined, it is clear that certain subsets of the population are particularly vulnerable to fluoride’s toxicity. Populations that have heightened susceptibility to fluoride include infants, individuals with kidney disease, individuals with nutrient deficiencies (particularly calcium and iodine), and individuals with medical conditions that cause excessive thirst.

To see a complete list of FAN’s research on fluoride’s health effects, click here. 

How do I avoid fluoride from my tap water?

If you live in a community that fluoridates its water supply, there are several options to avoid drinking the fluoride that is added. Unfortunately, each of these options will cost money (unless you happen to have access to a free source of spring water). The options include:

Spring water: Most spring water contains very low levels of fluoride (generally less than 0.1 ppm). To see the fluoride levels in popular brands of water, click here.

Water filtration: Many water filters (e.g., Brita & Pur) use an “activated carbon” filter that does not remove fluoride. Water filters that do remove fluoride include reverse osmosis, deionizers that use ion-exchange resin, and activated alumina. To learn more, click here.

Water Distillation: Distilling water is an effective way of removing fluoride from water. Whereas a water filter is installed directly into the sink, a distillation unit is a separate device that can be stored on your countertop.

What can I do to minimize fluoride exposure for myself and my family?

My child has dental fluorosis. What can we do to fix it?

The tooth discoloration that fluorosis causes can be reduced, and sometimes eliminated, through cosmetic treatment. Treatment options for fluorosis, however, will depend on the severity of the fluorosis. For more information on three common treatment options, click here.

If our water does not contain fluoride, should we give our child fluoride supplements?

Fluoride supplements were developed on the incorrect assumptions that fluoride is a nutrient and is effective when swallowed. Modern research has found that, while fluoride supplements greatly increase the risk of dental fluorosis, they do little to reduce tooth decay. Most western countries have thus begun to phase out the use of fluoride supplements, and even the American Dental Association now only recommends them for children who are at particularly high risk of tooth decay. Read more.