Know Your Environment. Protect Your Health.

Fluoride

Danbury Water Department

Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems to prevent cavities and support oral health in people.

In 2015, the Department of Health and Human Services updated its recommendation of an optimal level of 0.7 parts per million, or ppm, added to drinking water based on the health benefits of tooth decay prevention. Studies have shown that fluoride added to community water systems at this level reduces dental cavities, especially in children.

And studies have conclusively shown that fluoride in toothpaste and mouthwash can also provide these benefits. Read More.

Health Concerns

Although the HHS-recommended level of 0.7 ppm can help promote oral health in children and adults, this level is likely too high for bottle-fed babies. EWG recommends that caregivers mix baby formula with fluoride-free water.

And fluoride in water at higher levels can be detrimental for everyone, especially children.

Long-term ingestion of higher levels of fluoride in water increases dental fluorosis, which includes mottling, pitting and weakening of the teeth in children.

A 2024 authoritative assessment by the National Toxicology Program found that higher levels of fluoride exposure, such as drinking water containing more than 1.5 ppm of fluoride, are associated with lower IQ in children. The conclusion was based on studies in human populations outside of the U.S.

Affecting systems with naturally occurring fluoride, EPA’s maximum legal limit is set at 4 parts per million (ppm) to prevent skeletal fluorosis, a condition where bones become brittle and more susceptible to fracture. But these effects may occur at lower levels of exposure, raising concerns that the current limit may not adequately protect public health.

 

25

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.358 ppm440.0300 ppm - 0.650 ppm
20190.302 ppm550.0400 ppm - 0.730 ppm
20200.318 ppm42ND - 0.680 ppm
20210.348 ppm42ND - 0.710 ppm
20220.275 ppm42ND - 0.600 ppm
20230.385 ppm42ND - 0.810 ppm

ppm = parts per million

State, National, and Health Guidelines for Drinking Water

EPA Maximum Contaminant
Level (MCL): 4 ppm

ppm = parts per million

All test results

Date Lab ID Result
2018-04-12212690GE0.110 ppm
2018-04-12212687GE0.0300 ppm
2018-10-12IOC1 2005089400.640 ppm
2018-10-12IOC1 2005089390.650 ppm
2019-04-11IOC1 2005281820.730 ppm
2019-04-11IOC1 2005281810.620 ppm
2019-04-11IOCR 2005281850.0500 ppm
2019-04-11IOCR 2005281870.0400 ppm
2019-05-16IOCR 200532591A0.0700 ppm
2020-08-20IOCR 200587329ND
2020-08-20IOCR 200587327ND
2020-08-20IOC1 2005873280.680 ppm
2020-08-20IOC1 2005873300.590 ppm
2021-04-15IOC1 2006132970.710 ppm
2021-04-15IOC1 2006132950.680 ppm
2021-04-15IOCR 200613294ND
2021-04-15IOCR 200613296ND
2022-06-072873290.600 ppm
2022-06-072873250.500 ppm
2022-06-07287323ND
2022-06-07287327ND
2023-01-12304532ND
2023-01-12304533ND
2023-05-15N3E0590-02PPS0.810 ppm
2023-05-15N3E0590-01PPS0.728 ppm