Hydrofluoric acid, also known as HF, is a highly corrosive, toxic and volatile acid. It is a colorless and odorless solution composed of hydrogen and fluorine. Hydrofluoric acid is commonly used in the production of a variety of chemicals, such as refrigerants and plasticizers. It is also used in the etching of glass and metal, as well as in the cleaning of metals. HF is known to be particularly dangerous, as it can easily dissolve glass and even burn through human skin, leaving behind deep and painful burns.