Fluoride
Missouri American St. Louis County & St. Charles County
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems. Read More.
Fluoride has been promoted as a chemical that reduces dental cavities. Yet it is now well-established that fluoride primarily exerts its protective effects through topical mechanisms, such as sodium fluoride in toothpaste and mouthwash. In contrast, long-term ingestion of fluoride in water increases dental fluorosis, which includes mottling, pitting and weakening of the teeth. 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 fractures, although these effects may occur at lower doses.
Even fluoride levels of 0.7 ppm, the amount of fluoride in drinking water recommended by the U.S. Public Health Service, can result in too much fluoride for bottle-fed babies. EWG recommends that caregivers mix baby formula with fluoride-free water. The National Toxicology Program is investigating the potential for low doses of fluoride to alter thyroid function and childhood brain development.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 0.617 ppm | 27 | 27 | 0.560 ppm - 0.700 ppm |
| 2015 | 0.606 ppm | 17 | 17 | 0.520 ppm - 0.680 ppm |
| 2016 | 0.635 ppm | 17 | 17 | 0.590 ppm - 0.700 ppm |
| 2017 | 0.628 ppm | 17 | 17 | 0.580 ppm - 0.690 ppm |
| 2018 | 0.605 ppm | 17 | 17 | 0.560 ppm - 0.660 ppm |
| 2019 | 0.604 ppm | 17 | 17 | 0.530 ppm - 0.690 ppm |
ppm = parts per million
State and national drinking water standards and health guidelines
EPA Maximum Contaminant
Level (MCL) 4 ppm
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-01-15 | 24590901 | 0.680 ppm |
| 2014-02-19 | 24690801 | 0.560 ppm |
| 2014-03-19 | 24971301 | 0.600 ppm |
| 2014-04-15 | 25143201 | 0.640 ppm |
| 2014-04-15 | 25144101 | 0.630 ppm |
| 2014-04-15 | 25144401 | 0.630 ppm |
| 2014-04-16 | 25140901 | 0.600 ppm |
| 2014-04-16 | 25141401 | 0.580 ppm |
| 2014-04-16 | 25142301 | 0.580 ppm |
| 2014-05-14 | 25591801 | 0.610 ppm |
| 2014-06-19 | 25856501 | 0.620 ppm |
| 2014-07-23 | 26142501 | 0.590 ppm |
| 2014-07-23 | AC29361 | 0.670 ppm |
| 2014-07-23 | AC29362 | 0.580 ppm |
| 2014-07-23 | AC29363 | 0.620 ppm |
| 2014-07-23 | AC29364 | 0.660 ppm |
| 2014-07-23 | AC29365 | 0.700 ppm |
| 2014-07-29 | 26956301 | 0.630 ppm |
| 2014-07-29 | 26956401 | 0.650 ppm |
| 2014-07-29 | 26956501 | 0.660 ppm |
| 2014-07-29 | 26956601 | 0.650 ppm |
| 2014-07-29 | 26956701 | 0.630 ppm |
| 2014-08-19 | 26547501 | 0.580 ppm |
| 2014-09-09 | 26905801 | 0.590 ppm |
| 2014-10-09 | 27159201 | 0.570 ppm |
| 2014-11-06 | 27380001 | 0.570 ppm |
| 2014-12-04 | 27654401 | 0.580 ppm |
| 2015-01-13 | 28273001 | 0.590 ppm |
| 2015-02-12 | 28153101 | 0.600 ppm |
| 2015-03-10 | 28412101 | 0.570 ppm |
| 2015-04-22 | 28624201 | 0.620 ppm |
| 2015-04-22 | 28625601 | 0.580 ppm |
| 2015-04-22 | 28624701 | 0.610 ppm |
| 2015-04-22 | 28626501 | 0.610 ppm |
| 2015-04-22 | 28627401 | 0.650 ppm |
| 2015-04-22 | 28627701 | 0.520 ppm |
| 2015-05-12 | 28884301 | 0.620 ppm |
| 2015-06-04 | 29188001 | 0.620 ppm |
| 2015-07-16 | 29461301 | 0.550 ppm |
| 2015-08-25 | 29801101 | 0.630 ppm |
| 2015-09-15 | 30123501 | 0.630 ppm |
| 2015-10-27 | 30314401 | 0.610 ppm |
| 2015-11-12 | 30646801 | 0.610 ppm |
| 2015-12-03 | 30785301 | 0.680 ppm |
| 2016-01-11 | 30934701 | 0.630 ppm |
| 2016-02-16 | 31262701 | 0.640 ppm |
| 2016-03-02 | 31419301 | 0.590 ppm |
| 2016-04-05 | 31775701 | 0.630 ppm |
| 2016-04-05 | 31777301 | 0.600 ppm |
| 2016-04-05 | 31776301 | 0.660 ppm |
| 2016-04-20 | 31778301 | 0.590 ppm |
| 2016-04-20 | 31779301 | 0.620 ppm |
| 2016-04-20 | 31779601 | 0.660 ppm |
| 2016-05-17 | 31963501 | 0.590 ppm |
| 2016-06-10 | 32186001 | 0.680 ppm |
| 2016-07-06 | 32596201 | 0.650 ppm |
| 2016-08-16 | 33016901 | 0.700 ppm |
| 2016-09-09 | 33277401 | 0.620 ppm |
| 2016-10-05 | 33411201 | 0.620 ppm |
| 2016-11-10 | 33703301 | 0.660 ppm |
| 2016-12-07 | 33976001 | 0.660 ppm |
| 2017-01-11 | 34319701 | 0.650 ppm |
| 2017-02-02 | 34566301 | 0.620 ppm |
| 2017-03-08 | 34855401 | 0.610 ppm |
| 2017-04-11 | 35123001 | 0.590 ppm |
| 2017-04-11 | 35121701 | 0.580 ppm |
| 2017-04-11 | 35122701 | 0.610 ppm |
| 2017-04-19 | 35119201 | 0.650 ppm |
| 2017-04-19 | 35119701 | 0.670 ppm |
| 2017-04-19 | 35120701 | 0.600 ppm |
| 2017-05-25 | 35402601 | 0.640 ppm |
| 2017-06-16 | 35752001 | 0.620 ppm |
| 2017-07-14 | 36141801 | 0.590 ppm |
| 2017-08-17 | 36572401 | 0.650 ppm |
| 2017-09-19 | 36995101 | 0.640 ppm |
| 2017-10-17 | 37227701 | 0.600 ppm |
| 2017-11-09 | 37660701 | 0.660 ppm |
| 2017-12-12 | 37884801 | 0.690 ppm |
| 2018-01-19 | 38144001 | 0.630 ppm |
| 2018-02-14 | 38583701 | 0.650 ppm |
| 2018-03-20 | 38825401 | 0.570 ppm |
| 2018-04-06 | 39051101 | 0.570 ppm |
| 2018-04-06 | 39051501 | 0.620 ppm |
| 2018-04-06 | 39052401 | 0.560 ppm |
| 2018-04-16 | 39053301 | 0.580 ppm |
| 2018-04-16 | 39054201 | 0.660 ppm |
| 2018-04-16 | 39054501 | 0.590 ppm |
| 2018-05-10 | 39345301 | 0.570 ppm |
| 2018-06-19 | 39790701 | 0.630 ppm |
| 2018-07-17 | 40294101 | 0.590 ppm |
| 2018-08-14 | 40561001 | 0.580 ppm |
| 2018-09-12 | 40929601 | 0.590 ppm |
| 2018-10-09 | 41290601 | 0.630 ppm |
| 2018-11-06 | 41789101 | 0.650 ppm |
| 2018-12-10 | 42214401 | 0.620 ppm |
| 2019-01-09 | 42526001 | 0.610 ppm |
| 2019-02-11 | 43199201 | 0.640 ppm |
| 2019-03-12 | 43440401 | 0.610 ppm |
| 2019-04-08 | 43597901 | 0.640 ppm |
| 2019-04-08 | 43598301 | 0.630 ppm |
| 2019-04-08 | 43598401 | 0.600 ppm |
| 2019-04-09 | 43599301 | 0.690 ppm |
| 2019-04-09 | 43600201 | 0.620 ppm |
| 2019-04-09 | 43600301 | 0.600 ppm |
| 2019-05-08 | 43958701 | 0.590 ppm |
| 2019-06-12 | 44583201 | 0.570 ppm |
| 2019-07-10 | 45230801 | 0.630 ppm |
| 2019-08-13 | 45741901 | 0.580 ppm |
| 2019-09-12 | 46388001 | 0.610 ppm |
| 2019-10-07 | 46956901 | 0.540 ppm |
| 2019-11-14 | 47092201 | 0.570 ppm |
| 2019-12-10 | 47532101 | 0.530 ppm |