Nitric acid, also known as aqua fortis, is an acid composed of hydrogen, nitrogen, and oxygen with the chemical formula HNO3. It is highly corrosive and can cause serious burns on contact with skin or eyes. Nitric acid is one of the most important industrial chemicals, used in a wide variety of industries including the production of explosives, fertilizers, dyes, plastics, and pharmaceuticals. It is also used in metalworking, etching, and other industrial processes.