Public Health Service Recommendation for Fluoride Concentration in Drinking Water for Prevention of Dental Caries

Through this final recommendation, the U.S. Public Health Service (PHS) updates and replaces its 1962 Drinking Water Standards related to community water fluoridation--the controlled addition of a fluoride compound to a community water supply to achieve a concentration optimal for dental caries prevention. For these community water systems that add fluoride, PHS now recommends an optimal fluoride concentration of 0.7 milligrams/liter (mg/L). In this guidance, the optimal concentration of fluoride in drinking water is the concentration that provides the best balance of protection from dental caries while limiting the risk of dental fluorosis. The earlier PHS recommendation for fluoride concentrations was based on outdoor air temperature of geographic areas and ranged from 0.7-1.2 mg/L. This updated guidance is intended to apply to community water systems that currently fluoridate or that will initiate fluoridation, and is based on considerations that include: •  Scientific evidence related to the effectiveness of water fluoridation in caries prevention and control across all age groups, •  Fluoride in drinking water as one of several available fluoride sources, •  Trends in the prevalence and severity of dental fluorosis, and •  Current evidence on fluid intake of children across various outdoor air temperatures.