Hydrofluoric acid HF is aqueous solution of hydrogen fluoride. It's colourless and transparent, having strong and irritative smell and causticity. It can pickling such materials containing SiO 2 as glass quickly.

Hydrofluoric-Acid is a clear, colorless, smoky, corrosive liquid in aqueous solution of hydrogen acid fluoride gas, with a sharp,

pungent odor. Hydrofluoric-acid is a weak acid that is extremely corrosive and can strongly corrode metals, glass and objects containing silicon. Burns that are difficult to heal if they are inhaled or come into contact with skin. Fluorite (calcium fluoride) and concentrated acid sulphuric are commonly used in laboratories, sealed in plastic bottles and kept in a cool place.The principal use of hydrofluoric acid is in organofluorine chemistry. Many organofluorine compounds are prepared using HF as the fluorine source, including Teflon, fluoropolymers, fluorocarbons, and refrigerants such as freon. Many pharmaceuticals contain fluorine.

Most high-volume inorganic fluoride compounds are prepared from hydrofluoric acid. Foremost are Na3AlF6, cryolite, and AlF3, aluminium trifluoride. A molten mixture of these solids serves as a high-temperature solvent for the production of metallic aluminium. Other inorganic fluorides prepared from hydrofluoric acid include sodium fluoride and uranium hexafluoride.

Hydrofluoric Acid is used in the semiconductor industry as a major component of Wright etch and buffered oxide etch, which are used to clean silicon wafers. In a similar manner it is also used to etch glass by treatment with silicon dioxide to form gaseous or water-soluble silicon fluorides. It can also be used to polish and frost glass.