The fluoride added to 90% of drinking water is hydrofluoric acid which is a compound of fluorine that is a chemical by-product of alumina, steel, cement, phosphate, and nuclear weapons manufacturing. Hydrofluoric acid is used to refine high octane gasoline, to make fluorocarbons and chlorofluorocarbons for freezers and air conditioners, and to manufacture computer screens, fluorescent light bulbs, semiconductors, plastics, herbicides, and toothpaste.