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EWG's Tap Water Database — 2019 UPDATE

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Fluoride

Marshall Waterworks

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.

 

150

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20121.18 ppm24241.10 ppm - 1.28 ppm
20130.708 ppm24240.587 ppm - 1.15 ppm
20140.625 ppm27270.0921 ppm - 0.810 ppm
20150.712 ppm24240.629 ppm - 0.800 ppm
20160.672 ppm24240.474 ppm - 0.860 ppm
20170.563 ppm27270.0870 ppm - 0.858 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
2012-01-03IW0114561.11 ppm
2012-01-03IW0114561.12 ppm
2012-02-01IW0121931.13 ppm
2012-02-01IW0121931.15 ppm
2012-03-05IW0133831.11 ppm
2012-03-05IW0133831.13 ppm
2012-04-02IW0146441.15 ppm
2012-04-02IW0146441.21 ppm
2012-05-01IW0169181.17 ppm
2012-05-01IW0169181.18 ppm
2012-06-04IW0197881.21 ppm
2012-06-04IW0197881.22 ppm
2012-07-02IX0000881.22 ppm
2012-07-02IX0000881.28 ppm
2012-08-06IX0033911.17 ppm
2012-08-06IX0033911.19 ppm
2012-09-04IX0061641.19 ppm
2012-09-04IX0061641.24 ppm
2012-10-02IX0092001.10 ppm
2012-10-02IX0092001.20 ppm
2012-11-06IX0111701.16 ppm
2012-11-06IX0111701.24 ppm
2012-12-03IX0122871.17 ppm
2012-12-03IX0122871.22 ppm
2013-01-02IX0134451.09 ppm
2013-01-02IX0134451.15 ppm
2013-02-04IX0146620.780 ppm
2013-02-04IX0146620.860 ppm
2013-03-04IX0161840.600 ppm
2013-03-04IX0161840.700 ppm
2013-04-02IX0180040.660 ppm
2013-04-02IX0180040.730 ppm
2013-05-06707650010.587 ppm
2013-05-06707650010.640 ppm
2013-06-03760000010.589 ppm
2013-06-03760000010.670 ppm
2013-07-01823820010.599 ppm
2013-07-01823820010.610 ppm
2013-08-05891290010.601 ppm
2013-08-05891290010.640 ppm
2013-09-03948130010.660 ppm
2013-09-03948130010.665 ppm
2013-10-011013020010.651 ppm
2013-10-011013020010.660 ppm
2013-11-041069330010.706 ppm
2013-11-041069330010.780 ppm
2013-12-021109210010.659 ppm
2013-12-021109210010.710 ppm
2014-01-061148000010.681 ppm
2014-01-061148000010.710 ppm
2014-02-031179860010.642 ppm
2014-02-031179860010.700 ppm
2014-02-051184440010.109 ppm
2014-02-111190960010.0982 ppm
2014-02-191201530010.0921 ppm
2014-03-031212710010.700 ppm
2014-03-031212710010.706 ppm
2014-04-011253180010.667 ppm
2014-04-011253180010.670 ppm
2014-05-051301060010.617 ppm
2014-05-051301060010.690 ppm
2014-06-021357870010.623 ppm
2014-06-021357870010.680 ppm
2014-07-011423010010.667 ppm
2014-07-011423010010.720 ppm
2014-08-051491700010.673 ppm
2014-08-051491700010.680 ppm
2014-09-021542620010.662 ppm
2014-09-021542620010.710 ppm
2014-10-061614410010.683 ppm
2014-10-061614410010.700 ppm
2014-11-031663350010.720 ppm
2014-11-031663350010.733 ppm
2014-12-011701320010.744 ppm
2014-12-011701320010.810 ppm
2015-01-051741040010.640 ppm
2015-01-051741040010.680 ppm
2015-02-021776440010.629 ppm
2015-02-021776440010.660 ppm
2015-03-021812180010.681 ppm
2015-03-021812180010.710 ppm
2015-04-011857210010.689 ppm
2015-04-011857210010.690 ppm
2015-05-041907320010.664 ppm
2015-05-041907320010.730 ppm
2015-06-011964860010.690 ppm
2015-06-011964860010.695 ppm
2015-07-072037000010.646 ppm
2015-07-072037000010.660 ppm
2015-08-032089790010.796 ppm
2015-08-032089790010.800 ppm
2015-09-012147120010.720 ppm
2015-09-012147120010.739 ppm
2015-10-052214760010.713 ppm
2015-10-052214760010.744 ppm
2015-11-022267420010.779 ppm
2015-11-022267420010.785 ppm
2015-12-012307920010.774 ppm
2015-12-012307920010.785 ppm
2016-01-042343710010.680 ppm
2016-01-042343710010.689 ppm
2016-02-012380800010.733 ppm
2016-02-012380800010.790 ppm
2016-03-022421210010.775 ppm
2016-03-022421210010.860 ppm
2016-04-042468690010.716 ppm
2016-04-042468690010.766 ppm
2016-05-022519230010.713 ppm
2016-05-022519230010.748 ppm
2016-06-062585900010.631 ppm
2016-06-062585900010.660 ppm
2016-07-052642340010.598 ppm
2016-07-052642340010.677 ppm
2016-08-012696760010.589 ppm
2016-08-012696760010.597 ppm
2016-09-062757910010.644 ppm
2016-09-062757910010.669 ppm
2016-10-032818650010.704 ppm
2016-10-032818650010.712 ppm
2016-11-012869480010.474 ppm
2016-11-012869480010.504 ppm
2016-12-052914050010.594 ppm
2016-12-052914050010.597 ppm
2017-01-032948950010.594 ppm
2017-01-032948950010.651 ppm
2017-02-072989100010.595 ppm
2017-02-072989100010.613 ppm
2017-03-063027480010.607 ppm
2017-03-063027480010.636 ppm
2017-04-033075410010.608 ppm
2017-04-033075410010.626 ppm
2017-05-013130800010.621 ppm
2017-05-013130800010.656 ppm
2017-06-063203210010.583 ppm
2017-06-063203210010.598 ppm
2017-07-053262510010.536 ppm
2017-07-053262510010.561 ppm
2017-07-1810046180.0870 ppm
2017-07-1810046150.1000 ppm
2017-07-1810046210.110 ppm
2017-08-013326720010.492 ppm
2017-08-013326720010.500 ppm
2017-09-053401100010.851 ppm
2017-09-053401100010.858 ppm
2017-10-163493450010.548 ppm
2017-10-163493450010.605 ppm
2017-11-063527920010.630 ppm
2017-11-063527920010.631 ppm
2017-12-123592180010.645 ppm
2017-12-123592180010.664 ppm