3620 Nitric acid Nitric acid (HNO3), also known as aqua fortis and spirit of niter, is a highly corrosive mineral acid. The pure compound is colorless, but older samples tend to acquire a yellow cast due to decomposition into oxides of nitrogen and water. Most commercially available nitric acid has a concentration of 68%. When the solution contains more than 86% HNO3, it is referred to as fuming nitric acid. Nitric acid is the primary reagent used for nitration - the addition of a nitro group, typically to an organic molecule. The main industrial use of nitric acid is for the production of fertilizers. Nitric acid is neutralized with ammonia to give ammonium nitrate. The other main applications are for the production of explosives, nylon precursors, and specialty organic compounds. 7697-37-2 944 HNO3 62.995640 Colorless liquid -42°C 83°C Oral (L1137) ; inhalation (L1137) Nitric acid is a corrosive acid and a powerful oxidizing agent. The major hazard posed by it is chemical burns as it carries out acid hydrolysis with proteins (amide) and fats (ester) which consequently decomposes living tissue (e.g. skin and flesh). Concentrated nitric acid stains human skin yellow due to its reaction with the keratin. These yellow stains turn orange when neutralized. Systemic effects are unlikely, however, and the substance is not considered a carcinogen or mutagen. Intake of some amount of nitrates and nitrites is a normal part of the nitrogen cycle in humans. In vivo conversion of nitrates to nitrites can occur in the gastrointestional tract under the right conditions, significantly enhancing nitrates' toxic potency. The major metabolic pathway for nitrate is conversion to nitrite, and then to ammonia. Nitrites, nitrates, and their metabolites are excreted in the urine. (L1137) LD50: 138 ppm over 30 minutes (Inhalation, Rat) (A677) Ingested nitrate or nitrite under conditions that result in endogenous nitrosation is probably carcinogenic to humans (Group 2A). (L135) The main industrial use of nitric acid is for the production of fertilizers. Nitric acid is neutralized with ammonia to give ammonium nitrate. The other main applications are for the production of explosives, nylon precursors, and specialty organic compounds. Skin contact with nitric acid can cause redness, pain, and severe skin burns. Nitric acid may cause severe burns to the eye and permanent eye damage. Severe and rapid corrosive burns of the mouth, gullet and gastrointestinal tract will result if nitric acid is swallowed. Symptoms include burning, choking, nausea, vomiting and severe pain. Skin contact can cause redness, pain, and severe skin burns. Nitric acid may cause severe burns to the eye and permanent eye damage. Severe and rapid corrosive burns of the mouth, gullet and gastrointestinal tract will result if nitric acid is swallowed. Symptoms include burning, choking, nausea, vomiting and severe pain. The mainstay of treatment of any acid burn is copious irrigation with large amounts of tap water. To be most effective, treatment should be started immediately after exposure, preferably before arrival in the emergency department. Remove any contaminated clothing. Do not attempt to neutralize the burn with weak reciprocal chemicals (i.e. alkali for acid burns), because the heat generated from the chemical reaction may cause severe thermal injury. 2009-08-05T17:27:44Z 2026-04-14T20:32:28Z http://en.wikipedia.org/wiki/Nitric_acid C00244 48107 Nitric acid DB15995 6154 true O[N+]([O-])=O HNO3 InChI=1S/HNO3/c2-1(3)4/h(H,2,3,4) GRYLNZFGIOXLOG-UHFFFAOYSA-N 63.0128 62.995642903 Exogenous Liquid CHEMBL1352 919 CHEM002556 DTXSID5029685 NS00010065 nitric acid