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What is fluoride?

Fluoride is an abundant- naturally occurring element found in rocks, soil and fresh and ocean water. When fluoride is present in drinking water at optimal levels, it has been shown to promote oral health by preventing tooth decay.

Is my water fluoridated?

We have supplied fluoridated water to San Francisco residents and the majority of its wholesale customers since the early 1950s. 

How much fluoride is added to my water?

As of May 2015, we supplement naturally occurring fluoride in your drinking water to meet the optimal level set by the California Department of Public Health (0.7 part per million, or 0.7 milligram of fluoride per liter of water). This level of concentration is recommended by the United States Centers for Disease Control and Prevention (CDC).

Can you give an example of "parts per million" (ppm)?

There is one drop of fluoride in one million drops of water. Another example would be one inch in 16 miles; one cent in $10,000; one ounce of salt out of 62,500 pounds; one ounce of oil out of 7,812.5 gallons.

Fluoridation and Dental Fluorosis

Mandated by State law, water fluoridation is a widely accepted practice proven to be safe and effective for preventing and controlling tooth decay. As of May 2015, our water is optimally fluoridated at 0.7 mg/l. Infants fed formula mixed with water containing fluoride at the optimal level may have an increased chance of developing tiny white lines or streaks in their teeth. These marks are referred to as mild to very mild fluorosis, and are often only visible under a microscope. Even in cases where the marks are visible, they do not pose any health risk. CDPH and CDC consider it safe to use optimally fluoridated water for preparing infant formula. To lessen this chance of dental fluorosis, you may choose to use low-fluoride bottled water to prepare infant formula. Nevertheless, children may still develop dental fluorosis due to fluoride intake from other sources such as food, toothpaste and dental products. Contact your health provider or CDPH if you have concerns about dental fluorosis. 
Additional information can be found at the SWRCB website or CDC website.

Is fluoride OK for my pets?

Fluoride in levels administered for drinking water is safe for humans and all animals. Over 50 years of research and experience have shown fluoridation at optimal levels does not harm people or the environment. Leading scientists and health professionals, professional organizations and governments around the world support community water fluoridation.

What do health professionals say about fluoride?

Medical and dental experts endorse water fluoridation as the single, most effective public health measure to improve oral health. Through more than 50 years of extensive research, drinking fluoridated water has been scientifically proven to be safe and effective.

Why fluoridate drinking water?

  • The amount of natural fluoride in water supplies is generally not enough to provide oral health benefits. Water fluoridation is the addition of small amounts of fluoride to a water supply to achieve the optimal fluoride level that helps prevent tooth decay.
  • Fluoridated water benefits the entire community, children and adults of all ages, especially low-income and underserved populations.
  • California law requires water systems to fluoridate their water supplies, if funding is available.


More Fluoridation Materials
Last updated: 4/24/2020 11:48:21 AM