Rebecca

Hydrofluorosilic acid (HFA) is a compound containing fluoride ions.  Immediately upon addition to drinking water, HFA completely hydrolyzes (dissociates) into fluoride ions, identical to those which have always existed in water, and barely detectable trace contaminants in amounts far below EPA mandated maximum allowable levels of safety. After this point HFA no longer exists in that water.  It does not reach the tap.  It is not ingested.  It is therefore, of no concern, whatsoever. 

Steven D. Slott, DDS