About Fluoride
Fluoride can occur in drinking water naturally as a result of the geological composition of soils and bedrock. Most water supplies contain some naturally occurring fluoride. Fluoride also enters drinking water in discharge from fertilizer or aluminum factories. The decision to fluoridate a water supply is made by the State or local municipality. EPA has set the level of protection for fluoride at 4.0 mg/L or 4.0 ppm, to prevent potential health risk. 

Exposures to fluoride have increased since the early 1960s. At that time, drinking water and food and beverages prepared with fluoridated water accounted for nearly an individual’s entire fluoride intake. Today, exposure to fluoride comes from fluoridated dental products, as well as the voluntary addition of fluoride to drinking water.