Fluoride
City of San Diego
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.
214
Samples
0
Samples exceeding legal limit (MCL)
0
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 | 0.658 ppm | 36 | 36 | 0.490 ppm - 0.840 ppm |
| 2015 | 0.556 ppm | 36 | 36 | 0.300 ppm - 0.820 ppm |
| 2016 | 0.572 ppm | 35 | 35 | 0.320 ppm - 0.780 ppm |
| 2017 | 0.540 ppm | 34 | 34 | 0.300 ppm - 0.740 ppm |
| 2018 | 0.473 ppm | 37 | 37 | 0.189 ppm - 0.710 ppm |
| 2019 | 0.485 ppm | 36 | 36 | 0.170 ppm - 0.700 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 |
|---|---|---|
| 2014-01-06 | 9437-001-0000 | 0.750 ppm |
| 2014-01-06 | 9437-006-0000 | 0.750 ppm |
| 2014-01-06 | 9437-010-0000 | 0.640 ppm |
| 2014-02-03 | 9437-001-0000 | 0.620 ppm |
| 2014-02-03 | 9437-006-0000 | 0.760 ppm |
| 2014-02-03 | 9437-010-0000 | 0.520 ppm |
| 2014-03-03 | 9437-001-0000 | 0.610 ppm |
| 2014-03-03 | 9437-006-0000 | 0.760 ppm |
| 2014-03-04 | 9437-010-0000 | 0.520 ppm |
| 2014-04-07 | 9437-001-0000 | 0.800 ppm |
| 2014-04-07 | 9437-006-0000 | 0.790 ppm |
| 2014-04-07 | 9437-010-0000 | 0.490 ppm |
| 2014-05-20 | 9437-001-0000 | 0.640 ppm |
| 2014-05-20 | 9437-006-0000 | 0.750 ppm |
| 2014-05-20 | 9437-010-0000 | 0.570 ppm |
| 2014-06-02 | 9437-001-0000 | 0.650 ppm |
| 2014-06-02 | 9437-006-0000 | 0.740 ppm |
| 2014-06-02 | 9437-010-0000 | 0.550 ppm |
| 2014-07-07 | 9437-001-0000 | 0.810 ppm |
| 2014-07-07 | 9437-006-0000 | 0.840 ppm |
| 2014-07-07 | 9437-010-0000 | 0.510 ppm |
| 2014-08-04 | 9437-001-0000 | 0.660 ppm |
| 2014-08-04 | 9437-006-0000 | 0.670 ppm |
| 2014-08-04 | 9437-010-0000 | 0.550 ppm |
| 2014-09-02 | 9437-001-0000 | 0.660 ppm |
| 2014-09-02 | 9437-006-0000 | 0.730 ppm |
| 2014-09-02 | 9437-010-0000 | 0.500 ppm |
| 2014-10-06 | 9437-001-0000 | 0.580 ppm |
| 2014-10-06 | 9437-006-0000 | 0.710 ppm |
| 2014-10-06 | 9437-010-0000 | 0.620 ppm |
| 2014-11-03 | 9437-001-0000 | 0.610 ppm |
| 2014-11-03 | 9437-006-0000 | 0.830 ppm |
| 2014-11-03 | 9437-010-0000 | 0.590 ppm |
| 2014-12-01 | 9437-001-0000 | 0.610 ppm |
| 2014-12-01 | 9437-010-0000 | 0.550 ppm |
| 2014-12-08 | 9437-006-0000 | 0.740 ppm |
| 2015-01-05 | 9437-001-0000 | 0.560 ppm |
| 2015-01-05 | 9437-006-0000 | 0.810 ppm |
| 2015-01-05 | 9437-010-0000 | 0.560 ppm |
| 2015-02-02 | 9437-001-0000 | 0.550 ppm |
| 2015-02-02 | 9437-006-0000 | 0.820 ppm |
| 2015-02-02 | 9437-010-0000 | 0.610 ppm |
| 2015-03-02 | 9437-001-0000 | 0.490 ppm |
| 2015-03-02 | 9437-010-0000 | 0.440 ppm |
| 2015-03-17 | 9437-006-0000 | 0.740 ppm |
| 2015-04-06 | 9437-001-0000 | 0.580 ppm |
| 2015-04-06 | 9437-006-0000 | 0.780 ppm |
| 2015-04-06 | 9437-010-0000 | 0.510 ppm |
| 2015-05-04 | 9437-001-0000 | 0.530 ppm |
| 2015-05-04 | 9437-006-0000 | 0.660 ppm |
| 2015-05-04 | 9437-010-0000 | 0.500 ppm |
| 2015-06-01 | 9437-001-0000 | 0.540 ppm |
| 2015-06-01 | 9437-006-0000 | 0.640 ppm |
| 2015-06-01 | 9437-010-0000 | 0.480 ppm |
| 2015-07-06 | 9437-001-0000 | 0.480 ppm |
| 2015-07-06 | 9437-006-0000 | 0.410 ppm |
| 2015-07-06 | 9437-010-0000 | 0.410 ppm |
| 2015-08-03 | 9437-001-0000 | 0.360 ppm |
| 2015-08-03 | 9437-006-0000 | 0.550 ppm |
| 2015-08-03 | 9437-010-0000 | 0.390 ppm |
| 2015-09-09 | 9437-001-0000 | 0.560 ppm |
| 2015-09-09 | 9437-006-0000 | 0.510 ppm |
| 2015-09-09 | 9437-010-0000 | 0.350 ppm |
| 2015-10-05 | 9437-001-0000 | 0.640 ppm |
| 2015-10-05 | 9437-010-0000 | 0.300 ppm |
| 2015-10-06 | 9437-006-0000 | 0.610 ppm |
| 2015-11-02 | 9437-001-0000 | 0.700 ppm |
| 2015-11-02 | 9437-006-0000 | 0.690 ppm |
| 2015-11-02 | 9437-010-0000 | 0.580 ppm |
| 2015-12-07 | 9437-001-0000 | 0.580 ppm |
| 2015-12-07 | 9437-006-0000 | 0.620 ppm |
| 2015-12-07 | 9437-010-0000 | 0.480 ppm |
| 2016-01-04 | 9437-001-0000 | 0.640 ppm |
| 2016-01-04 | 9437-006-0000 | 0.580 ppm |
| 2016-01-04 | 9437-010-0000 | 0.530 ppm |
| 2016-02-01 | 9437-001-0000 | 0.630 ppm |
| 2016-02-01 | 9437-006-0000 | 0.600 ppm |
| 2016-02-01 | 9437-010-0000 | 0.560 ppm |
| 2016-03-07 | 9437-001-0000 | 0.530 ppm |
| 2016-03-07 | 9437-006-0000 | 0.570 ppm |
| 2016-03-07 | 9437-010-0000 | 0.440 ppm |
| 2016-04-04 | 9437-001-0000 | 0.620 ppm |
| 2016-04-04 | 9437-006-0000 | 0.610 ppm |
| 2016-04-04 | 9437-010-0000 | 0.350 ppm |
| 2016-05-02 | 9437-001-0000 | 0.610 ppm |
| 2016-05-02 | 9437-010-0000 | 0.480 ppm |
| 2016-06-06 | 9437-001-0000 | 0.600 ppm |
| 2016-06-06 | 9437-006-0000 | 0.580 ppm |
| 2016-06-06 | 9437-010-0000 | 0.390 ppm |
| 2016-07-06 | 9437-001-0000 | 0.610 ppm |
| 2016-07-06 | 9437-006-0000 | 0.700 ppm |
| 2016-07-06 | 9437-010-0000 | 0.320 ppm |
| 2016-08-01 | 9437-001-0000 | 0.670 ppm |
| 2016-08-01 | 9437-006-0000 | 0.720 ppm |
| 2016-08-01 | 9437-010-0000 | 0.400 ppm |
| 2016-09-12 | 9437-001-0000 | 0.680 ppm |
| 2016-09-12 | 9437-006-0000 | 0.680 ppm |
| 2016-09-12 | 9437-010-0000 | 0.380 ppm |
| 2016-10-03 | 9437-001-0000 | 0.740 ppm |
| 2016-10-03 | 9437-006-0000 | 0.710 ppm |
| 2016-10-03 | 9437-010-0000 | 0.420 ppm |
| 2016-11-07 | 9437-001-0000 | 0.700 ppm |
| 2016-11-07 | 9437-006-0000 | 0.700 ppm |
| 2016-11-07 | 9437-010-0000 | 0.340 ppm |
| 2016-12-05 | 9437-001-0000 | 0.780 ppm |
| 2016-12-05 | 9437-006-0000 | 0.710 ppm |
| 2016-12-05 | 9437-010-0000 | 0.430 ppm |
| 2017-01-03 | 9437-001-0000 | 0.740 ppm |
| 2017-01-03 | 9437-006-0000 | 0.680 ppm |
| 2017-02-06 | 9437-001-0000 | 0.480 ppm |
| 2017-02-06 | 9437-006-0000 | 0.640 ppm |
| 2017-02-22 | 9437-010-0000 | 0.420 ppm |
| 2017-03-06 | 9437-001-0000 | 0.690 ppm |
| 2017-03-06 | 9437-006-0000 | 0.630 ppm |
| 2017-03-06 | 9437-010-0000 | 0.570 ppm |
| 2017-04-03 | 9437-001-0000 | 0.650 ppm |
| 2017-04-03 | 9437-006-0000 | 0.530 ppm |
| 2017-04-03 | 9437-010-0000 | 0.450 ppm |
| 2017-05-01 | 9437-001-0000 | 0.640 ppm |
| 2017-05-01 | 9437-006-0000 | 0.550 ppm |
| 2017-05-01 | 9437-010-0000 | 0.300 ppm |
| 2017-06-05 | 9437-001-0000 | 0.520 ppm |
| 2017-06-05 | 9437-006-0000 | 0.550 ppm |
| 2017-06-05 | 9437-010-0000 | 0.430 ppm |
| 2017-07-10 | 9437-001-0000 | 0.500 ppm |
| 2017-07-10 | 9437-006-0000 | 0.490 ppm |
| 2017-07-10 | 9437-010-0000 | 0.390 ppm |
| 2017-08-07 | 9437-001-0000 | 0.510 ppm |
| 2017-08-07 | 9437-006-0000 | 0.500 ppm |
| 2017-08-07 | 9437-010-0000 | 0.440 ppm |
| 2017-09-11 | 9437-001-0000 | 0.520 ppm |
| 2017-09-11 | 9437-006-0000 | 0.560 ppm |
| 2017-09-11 | 9437-010-0000 | 0.570 ppm |
| 2017-10-02 | 9437-001-0000 | 0.590 ppm |
| 2017-10-02 | 9437-006-0000 | 0.520 ppm |
| 2017-10-02 | 9437-010-0000 | 0.540 ppm |
| 2017-11-06 | 9437-001-0000 | 0.530 ppm |
| 2017-11-06 | 9437-006-0000 | 0.540 ppm |
| 2017-11-06 | 9437-010-0000 | 0.560 ppm |
| 2017-12-04 | 9437-001-0000 | 0.570 ppm |
| 2017-12-04 | 9437-006-0000 | 0.550 ppm |
| 2018-01-08 | 9437-001-0000 | 0.530 ppm |
| 2018-01-08 | 9437-006-0000 | 0.500 ppm |
| 2018-01-24 | 9437-030-0000 | 0.189 ppm |
| 2018-02-05 | 9437-001-0000 | 0.450 ppm |
| 2018-02-05 | 9437-006-0000 | 0.540 ppm |
| 2018-02-05 | 9437-010-0000 | 0.460 ppm |
| 2018-03-05 | 9437-001-0000 | 0.670 ppm |
| 2018-03-05 | 9437-006-0000 | 0.530 ppm |
| 2018-03-05 | 9437-010-0000 | 0.560 ppm |
| 2018-04-02 | 9437-001-0000 | 0.590 ppm |
| 2018-04-02 | 9437-006-0000 | 0.590 ppm |
| 2018-04-02 | 9437-010-0000 | 0.510 ppm |
| 2018-05-07 | 9437-001-0000 | 0.710 ppm |
| 2018-05-07 | 9437-006-0000 | 0.640 ppm |
| 2018-05-07 | 9437-010-0000 | 0.580 ppm |
| 2018-05-09 | 9437-030-0000 | 0.280 ppm |
| 2018-06-04 | 9437-001-0000 | 0.670 ppm |
| 2018-06-04 | 9437-006-0000 | 0.650 ppm |
| 2018-06-04 | 9437-010-0000 | 0.540 ppm |
| 2018-07-02 | 9437-001-0000 | 0.300 ppm |
| 2018-07-02 | 9437-006-0000 | 0.670 ppm |
| 2018-07-02 | 9437-010-0000 | 0.440 ppm |
| 2018-08-06 | 9437-001-0000 | 0.610 ppm |
| 2018-08-06 | 9437-006-0000 | 0.550 ppm |
| 2018-08-06 | 9437-010-0000 | 0.300 ppm |
| 2018-09-04 | 9437-001-0000 | 0.230 ppm |
| 2018-09-04 | 9437-006-0000 | 0.630 ppm |
| 2018-09-04 | 9437-010-0000 | 0.380 ppm |
| 2018-10-01 | 9437-001-0000 | 0.640 ppm |
| 2018-10-01 | 9437-006-0000 | 0.630 ppm |
| 2018-10-01 | 9437-010-0000 | 0.340 ppm |
| 2018-11-05 | 9437-001-0000 | 0.270 ppm |
| 2018-11-05 | 9437-006-0000 | 0.240 ppm |
| 2018-11-30 | 9437-010-0000 | 0.240 ppm |
| 2018-12-03 | 9437-001-0000 | 0.250 ppm |
| 2018-12-03 | 9437-006-0000 | 0.230 ppm |
| 2018-12-03 | 9437-010-0000 | 0.370 ppm |
| 2019-01-07 | 9437-001-0000 | 0.300 ppm |
| 2019-01-07 | 9437-006-0000 | 0.620 ppm |
| 2019-01-16 | 9437-010-0000 | 0.500 ppm |
| 2019-02-04 | 9437-001-0000 | 0.630 ppm |
| 2019-02-04 | 9437-010-0000 | 0.520 ppm |
| 2019-02-06 | 9437-006-0000 | 0.610 ppm |
| 2019-03-04 | 9437-001-0000 | 0.640 ppm |
| 2019-03-04 | 9437-010-0000 | 0.450 ppm |
| 2019-03-19 | 9437-006-0000 | 0.603 ppm |
| 2019-04-02 | 9437-001-0000 | 0.510 ppm |
| 2019-04-02 | 9437-006-0000 | 0.690 ppm |
| 2019-04-02 | 9437-010-0000 | 0.510 ppm |
| 2019-05-06 | 9437-001-0000 | 0.180 ppm |
| 2019-05-06 | 9437-006-0000 | 0.460 ppm |
| 2019-05-06 | 9437-010-0000 | 0.450 ppm |
| 2019-06-03 | 9437-001-0000 | 0.270 ppm |
| 2019-06-03 | 9437-006-0000 | 0.210 ppm |
| 2019-06-03 | 9437-010-0000 | 0.510 ppm |
| 2019-07-01 | 9437-001-0000 | 0.260 ppm |
| 2019-07-01 | 9437-006-0000 | 0.470 ppm |
| 2019-07-01 | 9437-010-0000 | 0.320 ppm |
| 2019-08-05 | 9437-001-0000 | 0.170 ppm |
| 2019-08-05 | 9437-006-0000 | 0.520 ppm |
| 2019-08-05 | 9437-010-0000 | 0.430 ppm |
| 2019-09-03 | 9437-001-0000 | 0.700 ppm |
| 2019-09-03 | 9437-006-0000 | 0.600 ppm |
| 2019-09-03 | 9437-010-0000 | 0.560 ppm |
| 2019-10-07 | 9437-001-0000 | 0.480 ppm |
| 2019-10-07 | 9437-006-0000 | 0.520 ppm |
| 2019-10-07 | 9437-010-0000 | 0.530 ppm |
| 2019-11-04 | 9437-001-0000 | 0.540 ppm |
| 2019-11-04 | 9437-006-0000 | 0.530 ppm |
| 2019-11-04 | 9437-010-0000 | 0.490 ppm |
| 2019-12-02 | 9437-001-0000 | 0.580 ppm |
| 2019-12-02 | 9437-006-0000 | 0.580 ppm |
| 2019-12-02 | 9437-010-0000 | 0.520 ppm |