Fluoride
Western Greene
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 |
|---|---|---|---|---|
| 2014 | N/A | 0 | 0 | N/A |
| 2015 | N/A | 0 | 0 | N/A |
| 2016 | 0.427 ppm | 6 | 4 | ND - 0.820 ppm |
| 2017 | 0.725 ppm | 33 | 32 | ND - 1.15 ppm |
| 2018 | 0.789 ppm | 33 | 33 | 0.530 ppm - 0.990 ppm |
| 2019 | 0.714 ppm | 39 | 38 | ND - 1.22 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 |
|---|---|---|
| 2016-05-02 | Y161260013 | ND |
| 2016-07-27 | Y162100010 | ND |
| 2016-11-21 | Y163280027 | 0.820 ppm |
| 2016-12-19 | Y163640007 | 0.570 ppm |
| 2016-12-19 | Y163640008 | 0.600 ppm |
| 2016-12-19 | Y163640009 | 0.570 ppm |
| 2017-01-30 | Y170410002 | 0.630 ppm |
| 2017-01-30 | Y170410003 | 0.260 ppm |
| 2017-01-30 | Y170410004 | 0.660 ppm |
| 2017-03-03 | Y170860044 | 0.780 ppm |
| 2017-03-03 | Y170860045 | 0.400 ppm |
| 2017-03-03 | Y170860046 | 0.440 ppm |
| 2017-04-03 | Y171070012 | 0.350 ppm |
| 2017-04-03 | Y171070013 | 0.230 ppm |
| 2017-04-03 | Y171070014 | ND |
| 2017-04-27 | Y171280012 | 0.440 ppm |
| 2017-04-27 | Y171280013 | 1.000 ppm |
| 2017-04-27 | Y171280014 | 1.05 ppm |
| 2017-06-06 | Y171770040 | 0.550 ppm |
| 2017-06-16 | Y171770038 | 0.850 ppm |
| 2017-06-16 | Y171770039 | 1.06 ppm |
| 2017-07-13 | Y172050052 | 0.880 ppm |
| 2017-07-13 | Y172050053 | 1.15 ppm |
| 2017-07-13 | Y172050054 | 0.880 ppm |
| 2017-08-04 | Y172260049 | 1.03 ppm |
| 2017-08-04 | Y172260050 | 0.920 ppm |
| 2017-08-04 | Y172260051 | 0.800 ppm |
| 2017-08-31 | Y172540049 | 0.820 ppm |
| 2017-08-31 | Y172540050 | 0.910 ppm |
| 2017-08-31 | Y172540051 | 0.860 ppm |
| 2017-10-03 | Y173030017 | 0.800 ppm |
| 2017-10-03 | Y173030018 | 0.920 ppm |
| 2017-10-03 | Y173030019 | 0.790 ppm |
| 2017-10-31 | Y173170038 | 0.840 ppm |
| 2017-10-31 | Y173170039 | 0.850 ppm |
| 2017-10-31 | Y173170040 | 0.750 ppm |
| 2017-11-29 | Y173540046 | 0.840 ppm |
| 2017-11-29 | Y173540044 | 0.600 ppm |
| 2017-11-29 | Y173540045 | 0.580 ppm |
| 2018-01-04 | Y180180027 | 0.800 ppm |
| 2018-01-04 | Y180180028 | 0.770 ppm |
| 2018-01-04 | Y180180029 | 0.810 ppm |
| 2018-02-01 | Y180370036 | 0.610 ppm |
| 2018-02-01 | Y180370035 | 0.580 ppm |
| 2018-02-01 | Y180370034 | 0.750 ppm |
| 2018-03-01 | Y180720007 | 0.610 ppm |
| 2018-03-01 | Y180720009 | 0.720 ppm |
| 2018-03-01 | Y180720008 | 0.530 ppm |
| 2018-04-04 | Y180990061 | 0.780 ppm |
| 2018-04-04 | Y180990060 | 0.630 ppm |
| 2018-04-04 | Y180990059 | 0.770 ppm |
| 2018-05-08 | Y181340040 | 0.860 ppm |
| 2018-05-08 | Y181340041 | 0.910 ppm |
| 2018-05-08 | Y181340042 | 0.880 ppm |
| 2018-06-05 | Y181620052 | 0.910 ppm |
| 2018-06-05 | Y181620054 | 0.990 ppm |
| 2018-06-05 | Y181620053 | 0.990 ppm |
| 2018-06-29 | Y181900015 | 0.750 ppm |
| 2018-06-29 | Y181900016 | 0.960 ppm |
| 2018-06-29 | Y181900017 | 0.820 ppm |
| 2018-08-01 | Y182320031 | 0.950 ppm |
| 2018-08-01 | Y182320032 | 0.800 ppm |
| 2018-08-01 | Y182320030 | 0.780 ppm |
| 2018-09-06 | Y182610046 | 0.780 ppm |
| 2018-09-06 | Y182610047 | 0.840 ppm |
| 2018-09-06 | Y182610045 | 0.800 ppm |
| 2018-11-06 | Y183170056 | 0.760 ppm |
| 2018-11-06 | Y183170058 | 0.840 ppm |
| 2018-11-06 | Y183170057 | 0.910 ppm |
| 2018-12-04 | Y183510015 | 0.670 ppm |
| 2018-12-04 | Y183510014 | 0.810 ppm |
| 2018-12-04 | Y183510013 | 0.670 ppm |
| 2019-01-23 | Y190350012 | 0.790 ppm |
| 2019-01-23 | Y190350011 | 1.14 ppm |
| 2019-01-23 | Y190350010 | 0.740 ppm |
| 2019-02-06 | Y190500013 | 0.820 ppm |
| 2019-02-06 | Y190500012 | 0.700 ppm |
| 2019-02-06 | Y190500014 | 0.710 ppm |
| 2019-03-04 | Y190700050 | 0.780 ppm |
| 2019-03-04 | Y190700048 | 0.780 ppm |
| 2019-03-04 | Y190700049 | 0.600 ppm |
| 2019-04-09 | Y191010006 | 0.680 ppm |
| 2019-04-12 | Y191260026 | 0.670 ppm |
| 2019-04-12 | Y191260027 | 0.670 ppm |
| 2019-04-12 | Y191260028 | 0.660 ppm |
| 2019-05-07 | Y191330042 | 0.930 ppm |
| 2019-05-07 | Y191330043 | 1.22 ppm |
| 2019-05-07 | Y191330044 | 0.930 ppm |
| 2019-06-05 | Y191610062 | 0.750 ppm |
| 2019-06-06 | Y191610063 | 0.900 ppm |
| 2019-06-06 | Y191610064 | 0.760 ppm |
| 2019-07-02 | Y191960015 | 0.660 ppm |
| 2019-07-02 | Y191960016 | 0.890 ppm |
| 2019-07-02 | Y191960014 | 0.730 ppm |
| 2019-08-07 | Y192200012 | ND |
| 2019-08-09 | Y192320014 | 0.650 ppm |
| 2019-08-09 | Y192320015 | 0.650 ppm |
| 2019-08-09 | Y192320013 | 0.730 ppm |
| 2019-09-09 | Y192590005 | 0.770 ppm |
| 2019-09-09 | Y192590006 | 0.650 ppm |
| 2019-09-09 | Y192590004 | 0.780 ppm |
| 2019-10-09 | Y192830008 | 0.610 ppm |
| 2019-10-15 | Y193010005 | 0.880 ppm |
| 2019-10-15 | Y193010007 | 0.810 ppm |
| 2019-10-15 | Y193010006 | 0.890 ppm |
| 2019-11-25 | Y193430012 | 0.280 ppm |
| 2019-11-25 | Y193430011 | 0.280 ppm |
| 2019-11-25 | Y193430013 | 0.290 ppm |
| 2019-12-09 | Y193540005 | 0.660 ppm |
| 2019-12-09 | Y193540007 | 0.680 ppm |
| 2019-12-09 | Y193540006 | 0.710 ppm |