Fluoride is a weak anionic salt derived from  the element fluorine (F) that has been widely used to prevent tooth decay, and has been routinely added to public drinking water supplies in the U. S. since the 1960s.  Fresh and sea water carry trace amounts of fluoride, in the 0 to 1.4 mg/L range.

The recommended fluoride concentration for drinking water is 0.5 - 0.7 mg/L (2011, US EPA) or 0.5 - 1.5 mg/L (2011, World Health Organization). Excessive exposure to fluoride can cause white-spotted or pitted teeth.

 

Exposure Limits

Maine Maximum Exposure Guideline limit: 2.0 mg/L

USA Primary Drinking Water Standard limit: 4.0 mg/L

 

Resources

Wikipedia, "Fluoride"

Wikipedia: "Water Fluoridation"

Maine.gov: "Fluoride and Fluoridation" (webpage) - includes list of Maine towns fluoridating their public drinking water supply

Maine Oral Health Program, "Water Fluoridation" (webpage)

USA Centers for Disease Control "Community Water Fluoridation" (webpage)

USA Centers for Disease Control, Toxic FAQ: "Fluorides, Hydrogen Fluoride, and Fluorine"

"Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention" (Peckham, Stephen and Niyi Awofeso. TheScientificWorldJournal vol. 2014 293019. 26 Feb. 2014)

MEL Test Methods for Fluoride

Drinking Water –  EPA 300.0 (SDWA Compliant)
Wastewater – EPA 300.0 (NPDES Compliant)
Solids –  EPA 9056  (RCRA Compliant)

Sample Requirements

Wastewater/Drinking Water:

Container: plastic only
Volume: 60 mL
Hold Time: 28 days
Preservation: ≤6° C

Solids:

Container: plastic only
Volume: n/a
Hold Time: 28 days
Preservation: ≤6° C