Nitric acid is found in nature, and it can be synthetically produced in a laboratory. Free nitric acid is found in rainwater. It's also an ingredient in fertilizers, explosives such as nitroglycerin and TNT, dyes, plastics, rocket propellants and cleaning solutions. In the laboratory, nitric acid is made by distilling nitrates and sulfuric acid.
According to Encyclopedia.com. nitric acid is a colorless or pale liquid that is highly corrosive and poisonous. One of the strongest mineral acids, nitric acid is a strong oxidizing agent that readily ionizes in solution and conducts electricity well. The substance reacts with metals, oxides and hydroxides to form nitrate salts.
Commercially available forms of nitric acid usually contain 52 to 68 percent nitric acid in water. In solution concentrations of 86 percent or more, nitric acid is called fuming nitric acid. Two types of fuming nitric acid exist: white fuming nitric acid and red fuming nitric acid. Treating either form yields inhibited fuming nitric acid, which is more resistant to corrosion in metals.
Nitric acid causes burns when it comes in contact with the skin. Swallowing it causes burns to the mouth and ulceration to the throat. Relief occurs when an alkaline solution is administered as treatment.