What is the recommended concentration of fluoride in drinking water in parts per million?

The recommended concentration of fluoride in drinking water is set at 1 part per million (ppm). This level has been established based on extensive research showing that fluoride at this concentration is effective in reducing dental caries (cavities) while minimizing the risk of dental fluorosis, which can occur with excessive fluoride exposure.

Several health organizations, including the Centers for Disease Control and Prevention (CDC) and the American Dental Association (ADA), endorse this level because it strikes a balance between protective benefits for dental health and safety for the population. Fluoride works by strengthening tooth enamel, making it more resistant to decay, which is particularly beneficial for children whose teeth are still developing.

Although higher concentrations, such as 1.5 ppm or 2 ppm, may have some increased protective effects, they also carry a higher risk of fluorosis, especially in younger children who may be more susceptible to the effects of higher fluoride levels. Conversely, concentrations like 0.5 ppm are below the optimal level and may not provide sufficient protection against tooth decay, particularly in areas with high rates of dental caries. Therefore, 1 ppm is considered the ideal and optimal level for community water fluoridation.