In some browsers, after entering your weight you may have to click outside the text entry box to make the calculation work. Elements for which there are no data will always give a value of zero for the weight. 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. All rights reserved.