Hydrofluosilicic acids (h2sif6) is an unstable poisonous corrosive acid know primarily in the form of its salts. Hydrofluosilicic acid is acidic yellow chemical soup, a by-product of fertilizer manufacturing plants, and contains lead, arsenic and mercury, as well as silico-fluoride compounds.
it is the most commonly used fluoridating chemical. This acid is also known as fluorosilicic acid, hexafluosilicic acid, and silicofluoric acid. The liquid may be fed directly into the raw water or may be diluted. Hydrofluosilicic acid is a popular choice in many water treatment plants because it is usually the least expensive fluoridation chemical and is the easiest to feed. However, it can be expensive to ship since it is a liquid and is heavier than the other fluoridation chemicals. Hydrofluosilicic acid is used in fertilizer industry, chemical industry, agriculture industry, etc.