“Fluoride provides an important public health benefit by helping to reduce cavities and tooth decay," said Susan Mayne, director of FDA’s Center for Food Safety and Applied Nutrition. "But too much fluoride over a long time when teeth are forming under the gums can cause changes in the appearance of tooth enamel, called dental fluorosis. Striking the right balance is especially important for children under the age of 8 as their permanent teeth are still forming."

The proposal only impacts bottled water with fluoride added by the manufacturer – it would not impact the level of allowable fluoride in bottles that contain fluoride from source water.

Some scientists are concerned that the standard for allowable fluoride in bottled water is still too high with this new proposed change, as excess fluoride's consequences can extend beyond dental issues.

"Given that fluoride can damage brain development, I would recommend that the maximum fluoride concentration in bottled water be kept at a lower level than 0.7 mg/L," Dr. Philippe Grandjean, an adjunct professor of environmental health at the Harvard TH Chan School of Public Health

https://www.usatoday.com/story/money/2019/04/03/fda-proposal-would-lower-amount-fluoride-allowed-bottled-water/3350469002/