Drinking Water Fluoridation
What is community water fluoridation?
Fluoride is natural to our environment. You can find it in soils and fresh and ocean water. Community water fluoridation adjusts the natural levels of fluoride to help prevent tooth decay.
Municipal community water systems in Minnesota must adjust fluoride in their water to maintain a fluoride concentration between 0.5 and 0.9 milligrams per liter (mg/L). One mg/L is the same as one part per million.
Fluoride is an efficient and equitable way to prevent one of the most common childhood diseases – dental decay. An estimated 51 million school hours in the United States are lost each year due to dental-related illness.
Studies show that community water fluoridation prevents at least 25 percent of tooth decay in children and adults, even in a time when fluoride is widely available from other sources, like fluoride toothpaste.
An overwhelming amount of scientific evidence indicates that fluoridation of community water supplies is safe.
The CDC, the American Medical Association (AMA), the World Health Organization (WHO), the American Dental Association (ADA), and more than 125 other national and international organizations recognize the public health benefits of water fluoridation for preventing dental decay.
Taking in too much fluoride during enamel development can lead to a dental condition known as dental fluorosis. Dental fluorosis can occur when a person consumes too much fluoride during enamel development. This can result in visual or physical changes to the teeth, such as white or brown spots or pitting. Severe dental fluorosis is not common when drinking water fluoride concentrations are below 2 mg/L.
On average, every dollar spent on fluoridation by a community saves $20 in avoided dental treatment costs. Over a person's lifetime, the cost of fluoridation is typically less than the cost of one dental filling.
Minnesota Statute 144.145 requires the fluoridation of water in all municipal water supplies except where natural levels are within the required fluoride concentration range of 0.5 to 0.9 milligrams per liter (mg/L).
Minnesota Rule 4720.0030 describes the required level of fluoride and monitoring of drinking water fluoride concentrations. This rule was recently revised. You can find information about the revision at Minnesota Fluoridation Rule Revision.
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 MDH. Samples are collected from distribution system locations that are representative of the entire drinking water system.
The United States Environmental Protection Agency (EPA) has established a maximum contaminant level (MCL) of 4.0 mg/L for fluoride. This limit prevents exposure to harmful levels of fluoride in drinking water. 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.
EPA also has a non-enforceable secondary MCL (SMCL) of 2.0 mg/L to limit cosmetic effects of fluoride, such as dental fluorosis.
Both the MCL and SMCL are higher than the Minnesota limit of 1.5 mg/L.
- American Dental Association
- Centers for Disease Control and Prevention (CDC)
- The Community Guide