On January 7, 2011, USEPA announced its intent to review the drinking water regulations for fluoride. This action is a follow up to the second Six Year Review (SY2), released March 2010.
USEPA has proposed a reference dose (RfD) for fluoride of 0.08 mg/kg/day for protection against pitting of the tooth enamel (severe dental fluorisis). The Agency believes that this value also protects against fractures and skeletal effects in adults. The RfD is the estimate of the daily exposure that is likely to be without harmful effect during a lifetime. A decision has not yet been made regarding any proposed revision to the current MCLG and MCL of 4 mg/L.