Drinking Water Fluoridation - EH: Minnesota Department of Health

Drinking Water Fluoridation

What is water fluoridation?

When used appropriately, fluoride (a naturally occurring element found in water, air, and soil) is a safe and effective agent that can be used to prevent and control tooth decay. Approximately 620 municipal public water supplies (PWSs) in Minnesota must add fluoride to their water, through fluoridation, in order to maintain a fluoride concentration between 0.9 and 1.5 milligrams per liter (mg/L).

How does water fluoridation help prevent tooth decay?

Consumption of fluoride in drinking water helps prevent tooth decay through direct contact with teeth throughout life and when consumed by children during the tooth forming years. At optimal levels, the Centers for Disease Control and Prevention (CDC) reports that community water fluoridation reduces childhood cavities by approximately 18 to 40 percent. Pit and fissure sealants, meticulous oral hygiene, and appropriate dietary practices also contribute to dental caries prevention and control. However, the CDC states that the most effective and widely used approaches have included water fluoridation.

Is water fluoridation safe?

An overwhelming amount of scientific evidence indicates that fluoridation of community water supplies is safe. Excessive intake of fluoride during enamel development can lead to a dental condition known as enamel fluorosis, a mottling of the tooth surface that may range from barely discernable markings to brown stains to surface pitting. The overall prevalence of severe forms of enamel fluorosis is very low when drinking water fluoride concentrations are below 2 mg/L.

Higher levels of fluoride exposure over a lifetime may cause a bone and joint condition described as skeletal fluorosis. Under certain conditions, fluoride can weaken bone and increase risk of fractures. The United States Environmental Protection Agency (EPA) has established a maximum contaminant level (MCL) of 4.0 mg/L to prevent exposure to harmful levels of fluoride in drinking water, as well as a secondary MCL (SMCL) of 2.0 mg/L to limit the severity and occurrence of cosmetic effects such as enamel fluorosis.

How does Minnesota law mandate and monitor community water fluoridation?

Minnesota Statute 144.145 requires the fluoridation of water in all municipal water supplies except where natural levels are sufficient.

Minnesota Rule 4720.0030 prescribes the required monitoring of drinking water fluoride concentrations. Municipal water supplies monitor system performance, collect daily samples, and submit reports and results to the Minnesota Department of Health (MDH) on a monthly basis. They also collect and submit quarterly duplicate samples to the MDH. Samples are collected from distribution system locations that are representative of the entire drinking water system.

Are there grants available for fluoridation of community water supplies?

See: Community Public Water Supply Fluoridation Grant Information

Where can I learn more about community fluoridation?

More water fluoridation information may also be found at these websites: For more information on water fluoridation:
Updated Monday, October 23, 2017 at 10:29AM