Fluoboric Acid 48% is a colorless and often caustic smelling poisonous liquid that is corrosive to metals and human tissue. It is made by by dissolving boron trifluoride in water or by adding boric acid to concentrated hydrofluoric acid and used as a solution or in the form of salts. Full-face respirators, face shields and gloves are commonly used when handling this acid. It is considered to be a Level 3 health hazard and can enter the body through skin, inhalation and ingestion. The strength of this acid is comparable to nitric acid, even though it has a weakly coordinating, non-oxidizing conjugate base. It is commonly used as a catalyst for alkylations and polymerizations. The liquid form is also used as an electrolyte in galvanic cell oxygen sensor systems. It is used most often as a plasticizer and as a plating agent and surface agent in the manufacture of metals.