Here are a few notes about the hazards and risks associated with fluorine. Fluorine gas is extremely corrosive and toxic. The free element has a characteristic pungent odour, detectable in concentrations as low as 20 ppb, which is below the safe working level. Exposure to low concentrations causes eye and lung irritation. Metal fluorides are very toxic.
Organic fluorides are generally much less toxic and are often quite harmless.
However in some areas, fluoride is not added to water, despite the benefits, as a consequence of civil rights activists who object to the addition of anything to water.