I used to be the ostensible fluoridation engineer for in my home state. I’m not actively involved in fluoridation any more, but I still follow news about it.
Last year, the U.S. Department of Health and Human Services (DHHS) proposed to change the optimized water fluoride concentration from a range of 0.7 to 1.2 mg/L to a simply 0.7 mg/L (Federal Register 76:9:2383). About the same time, the U.S. Environmental Protection Agency (EPA) released a dose-response study on the noncancer effects of fluoride.
So far, their have been no regulatory changes. After completing its review of fluoride, EPA could change the regulatory maximum contaminant level (MCL) if it deems it necessary. Even without a regulatory change, DHHS is expected to publish a final recommendation on optimal fluoride concentrations in drinking water and publish revisions to the Centers for Disease Control and Prevention’s Engineering and Administrative Recommendations for Water Fluoridation.