Fluoride

San Bernardino City

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.

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105

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	0.606 ppm	52	52	0.300 ppm - 1.70 ppm
2015	N/A	0	0	N/A
2016	N/A	0	0	N/A
2017	0.492 ppm	49	49	0.220 ppm - 1.30 ppm
2018	0.290 ppm	2	2	0.240 ppm - 0.340 ppm
2019	0.360 ppm	2	2	0.270 ppm - 0.450 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
2014-03-10	4790-030-0820	0.400 ppm
2014-07-29	4790-001-0548	1.70 ppm
2014-07-29	4790-002-0850	0.300 ppm
2014-07-29	4790-003-0840	0.400 ppm
2014-07-29	4790-005-1210	0.700 ppm
2014-07-29	4790-007-0920	0.300 ppm
2014-07-29	4790-014-0647	0.500 ppm
2014-07-29	4790-015-1421	1.10 ppm
2014-07-29	4790-017-1308	1.000 ppm
2014-07-29	4790-018-1255	1.20 ppm
2014-07-29	4790-021-1120	0.500 ppm
2014-07-29	4790-022-1100	0.600 ppm
2014-07-29	4790-023-1039	0.600 ppm
2014-07-29	4790-024-1034	0.500 ppm
2014-07-29	4790-030-0820	0.500 ppm
2014-07-29	4790-032-0955	1.50 ppm
2014-07-29	4790-034-0705	0.400 ppm
2014-07-29	4790-035-1150	0.700 ppm
2014-07-29	4790-036-0540	0.600 ppm
2014-07-29	4790-037-1135	0.700 ppm
2014-07-29	4790-038-0900	0.300 ppm
2014-07-29	4790-039-0842	0.300 ppm
2014-07-29	4790-040-0825	0.300 ppm
2014-07-29	4790-041-0910	0.400 ppm
2014-07-29	4790-043-0610	1.70 ppm
2014-07-29	4790-049-0645	0.400 ppm
2014-07-29	4790-051-1440	0.800 ppm
2014-07-29	4790-053-1030	0.700 ppm
2014-07-29	4790-054-1335	1.50 ppm
2014-07-29	4790-055-0956	0.300 ppm
2014-07-29	4790-056-1007	0.300 ppm
2014-07-29	4790-062-1355	1.50 ppm
2014-07-29	4790-063-1233	0.700 ppm
2014-07-29	4790-064-1330	0.500 ppm
2014-07-29	4790-065-1315	0.300 ppm
2014-07-29	4790-066-1300	0.600 ppm
2014-07-29	4790-067-1245	0.600 ppm
2014-07-29	4790-068-1230	0.600 ppm
2014-07-29	4790-069-1345	0.400 ppm
2014-07-29	4790-113-0805	0.400 ppm
2014-07-29	4790-114-0750	0.400 ppm
2014-07-29	4790-115-0735	0.300 ppm
2014-07-29	4790-116-0720	0.400 ppm
2014-07-29	4790-117-0700	0.400 ppm
2014-07-29	4790-118-0735	0.400 ppm
2014-07-29	4790-119-0757	0.400 ppm
2014-07-29	4790-126-0615	0.600 ppm
2014-09-05	4790-008-1121	0.300 ppm
2014-09-05	4790-052-1050	0.300 ppm
2014-10-29	4790-009-1500	0.400 ppm
2014-10-29	4790-031-1509	0.400 ppm
2014-12-01	4790-012-1410	0.400 ppm
2017-07-26	9590-002-0735	0.380 ppm
2017-07-26	9590-003-0805	0.280 ppm
2017-07-26	9590-005-0828	0.540 ppm
2017-07-26	9590-007-0630	0.290 ppm
2017-07-26	9590-008-1143	0.390 ppm
2017-07-26	9590-009-1127	0.390 ppm
2017-07-26	9590-030-0830	0.440 ppm
2017-07-26	9590-031-1106	0.370 ppm
2017-07-26	9590-032-0710	0.880 ppm
2017-07-26	9590-035-0710	0.540 ppm
2017-07-26	9590-036-0630	0.480 ppm
2017-07-26	9590-037-0803	0.610 ppm
2017-07-26	9590-049-0900	0.320 ppm
2017-07-26	9590-052-1212	0.330 ppm
2017-07-26	9590-065-1030	0.340 ppm
2017-07-26	9590-066-1005	0.560 ppm
2017-07-26	9590-067-0930	0.540 ppm
2017-07-26	9590-068-0906	0.560 ppm
2017-07-26	9590-113-1100	0.320 ppm
2017-07-26	9590-114-1030	0.330 ppm
2017-07-26	9590-115-1000	0.300 ppm
2017-07-26	9590-116-0942	0.370 ppm
2017-07-26	9590-117-0927	0.370 ppm
2017-07-27	9590-001-0615	1.30 ppm
2017-07-27	9590-015-1120	0.680 ppm
2017-07-27	9590-017-0830	0.680 ppm
2017-07-27	9590-018-0800	0.850 ppm
2017-07-27	9590-021-0630	0.300 ppm
2017-07-27	9590-022-0915	0.420 ppm
2017-07-27	9590-023-0805	0.410 ppm
2017-07-27	9590-024-0839	0.260 ppm
2017-07-27	9590-025-0730	0.280 ppm
2017-07-27	9590-034-0720	0.290 ppm
2017-07-27	9590-038-1201	0.220 ppm
2017-07-27	9590-040-1110	0.250 ppm
2017-07-27	9590-041-1140	0.280 ppm
2017-07-27	9590-043-0650	1.20 ppm
2017-07-27	9590-051-1045	0.770 ppm
2017-07-27	9590-054-0930	1.000 ppm
2017-07-27	9590-056-0658	0.260 ppm
2017-07-27	9590-062-1000	0.940 ppm
2017-07-27	9590-063-0850	0.700 ppm
2017-07-27	9590-118-0958	0.290 ppm
2017-07-27	9590-119-1030	0.310 ppm
2017-08-02	9590-012-0930	0.360 ppm
2017-08-02	9590-014-1040	0.400 ppm
2017-08-02	9590-039-1320	0.280 ppm
2017-08-02	9590-053-1400	1.000 ppm
2017-08-29	9590-069-1110	0.450 ppm
2018-01-12	9590-055-0830	0.240 ppm
2018-02-07	9590-064-1130	0.340 ppm
2019-08-09	4790-117-0945	0.270 ppm
2019-12-04	4790-024-0845	0.450 ppm