Know Your Environment. Protect Your Health.

Fluoride

Portland Water District - Greater Portland

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.

 

78

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.642 ppm13130.480 ppm - 0.720 ppm
20190.663 ppm13130.530 ppm - 0.730 ppm
20200.662 ppm13130.590 ppm - 0.760 ppm
20210.625 ppm13130.560 ppm - 0.690 ppm
20220.662 ppm13130.560 ppm - 0.820 ppm
20230.638 ppm13130.520 ppm - 0.800 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
2018-01-02W-180102-00320.720 ppm
2018-02-06W-180206-00330.680 ppm
2018-03-05W-180305-00210.670 ppm
2018-04-02W-180402-00190.690 ppm
2018-05-07W-180507-00200.650 ppm
2018-06-04W-180604-00200.660 ppm
2018-07-02W-180702-00220.620 ppm
2018-07-101807-01040-0010.480 ppm
2018-08-06W-180806-00210.600 ppm
2018-09-04W-180904-00330.600 ppm
2018-10-01W-181001-00210.630 ppm
2018-11-05W-181105-00210.630 ppm
2018-12-03W-181203-00200.720 ppm
2019-01-07W-190107-00200.710 ppm
2019-02-04W-190204-00180.710 ppm
2019-03-04W-190304-00200.620 ppm
2019-04-01W-190401-00180.660 ppm
2019-05-06W-190506-00180.650 ppm
2019-06-03W-190603-00200.610 ppm
2019-06-041906-00591-0010.530 ppm
2019-07-01W-190701-00180.620 ppm
2019-08-05W-190805-00180.710 ppm
2019-09-03W-190903-00340.690 ppm
2019-10-07W-191007-00180.660 ppm
2019-11-04W-191104-00200.720 ppm
2019-12-02W-191202-00180.730 ppm
2020-01-06W-200106-00190.670 ppm
2020-02-03W-200203-00200.670 ppm
2020-03-02W-200302-00180.620 ppm
2020-04-07W-200407-00220.660 ppm
2020-05-05W-200505-00360.660 ppm
2020-06-01W-200601-00200.640 ppm
2020-06-162006-02278-0010.590 ppm
2020-07-06W-200706-00200.660 ppm
2020-08-03W-200803-00180.660 ppm
2020-09-08W-200908-00300.680 ppm
2020-10-06W-201006-00290.680 ppm
2020-11-03W-201103-00300.760 ppm
2020-12-07W-201207-00180.660 ppm
2021-01-04W-210104-00200.670 ppm
2021-02-01W-210201-00220.630 ppm
2021-03-01W-210301-00200.560 ppm
2021-04-05W-210405-00200.680 ppm
2021-05-04W-210504-00300.640 ppm
2021-06-07W-210607-00210.600 ppm
2021-06-092106-01445-0010.590 ppm
2021-07-06W-210706-00440.600 ppm
2021-08-02W-210802-00270.690 ppm
2021-09-07W-210907-00310.650 ppm
2021-10-05W-211005-00340.610 ppm
2021-11-01W-211101-00190.600 ppm
2021-12-06W-211206-00180.600 ppm
2022-01-03W-220103-00200.600 ppm
2022-02-07W-220207-00190.590 ppm
2022-03-07W-220307-00170.620 ppm
2022-04-05W-220405-00250.610 ppm
2022-05-02W-220502-00200.640 ppm
2022-06-06W-220606-00200.620 ppm
2022-06-212206-03375-0010.560 ppm
2022-07-05W-220705-00230.600 ppm
2022-08-01W-220801-00200.780 ppm
2022-09-06W-220906-00260.740 ppm
2022-10-03W-221003-00180.820 ppm
2022-11-07W-221107-00170.740 ppm
2022-12-05W-221205-00170.690 ppm
2023-01-03W-230103-00260.800 ppm
2023-02-06W-230206-00190.580 ppm
2023-03-06W-230306-00170.670 ppm
2023-04-03W-230403-00190.600 ppm
2023-05-01W-230501-00170.650 ppm
2023-06-06W-230606-00330.680 ppm
2023-06-142306-03033-0010.520 ppm
2023-07-05W-230705-00280.630 ppm
2023-08-07W-230807-00150.640 ppm
2023-09-05W-230905-00250.620 ppm
2023-10-02W-231002-00150.660 ppm
2023-11-06W-231106-00150.630 ppm
2023-12-04W-231204-00170.620 ppm