Toxno Substance Profile
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Substance Name

Nitric acid
Identification Number: CASRN | 7697-37-2

  Substance Attributes


  • Metabolic Interference or Disruption

    Interferes with human metabolism. This can be a very serious thing. Some of these interference mechanics are well established. However, often long term effects and health consequences remain largely unknown. Additionally an emerging area of concern and one that is not currently studied, is the combined synergistic effects these metabolically disrupting chemicals have on human health.


    Metabolic interference happens when the substance produces highly reactive and often damaging intermediates during detoxification or when the substance binds to specific enzymes, important structural groups on molecules, receptors and membranes or targets DNA or mimics key nutrients.

  • Exposure Produces Health Symptoms

    Symptoms maybe short term or long term depending on the exposure duration and intensity and effects areas like Cardiovascular, Gastrointestinal, Cognition, Fatigue. A substance with this attribute may cause an allergic skin reaction, serious eye irritation, allergy or asthma symptoms or breathing difficulties if inhaled.

These attributes are ONLY based on peer-reviewed evidence. See link to Data Sources below. Everyone benefits from knowing this stuff. Please Share.



  • CATEGORIES: Household Toxin | Industrial/Workplace Toxin | Synthetic Toxin | Indirect Additives Used in Food Contact Substances | Inert Pesticide Ingredient USA - Food Use Permitted | A Hazardous Substance that may be found in the Australian Workplace
  • SUBSTANCE LINEAGE: Inorganic Compounds | Homogeneous Non-metal Compounds | Non-metal Oxoanionic Compounds | Non-Metal Nitrates | Non-metal Nitrites
  • SYNONYMS: Acide azotique | Acide nitrique | Acido nitrico | Acidum nitricum | Acidum Nitricum-Injeel Forte Liq (D6-D200) | Aqua fortis | Azotic acid | Azotowy kwas | Dynamite acid | Engraver's acid | Engravers acid | Fuming nitric acid | HNO3 | HONO2 | Hydrogen nitrate | hydrogen trioxonitrate(1-) | Hydroxidodioxidonitrogen | Kyselina dusicne | Nital | Nitraline | Nitrate | Nitric acid (red fuming) | Nitric acid anhydrous | Nitric acid fuming | Nitric acid red fuming | Nitric acid standard solution | Nitricum acidum | Nitrous fumes | Nitryl hydroxide | Red fuming nitric acid | RFNA | Salpetersaeure | Salpetersaure | Salpeterzuuroplossingen | Trioxonitric acid | [NO2(OH)]
  • DESCRIPTION: 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.
  • COMMENTS:

    From Safe Work Australia and the Hazardous Substances Information System (HSIS) in Australia:

    May intensify fire; oxidiser. Causes severe skin burns and eye damage | | A Hazardous Substance that may be found in the Australian Workplace. Check with your employer or health and safety officer. Stay informed and become aware of the dangers that surround you. This chemical is included on the list of recognised hazardous chemicals from the Safe Work Australia - Hazardous Substances Information System (HSIS) that is based on the Globally Harmonised System of Classification and Labelling of Chemicals (GHS)

    Work Health and Safety (WHS) Regulations are the basis for hazardous chemicals regulations in Commonwealth, State and Territory jurisdictions in Australia. Under the model WHS Regulations, manufacturers and importers of substances, mixtures and articles supplied for use in workplaces are required to determine whether they are hazardous to health and safety before supply. The model WHS Regulations mandate that the hazards of a chemical as determined by the Globally Harmonised System of Classification and Labelling of Chemicals (GHS) must be included in safety data sheets and on labels. There are transitional arrangements in place for moving to the GHS-based system.

    The GHS Hazardous Chemical Information List contains chemicals classified by an authoritative source (such as the European Commission or NICNAS) in accordance with the Globally Harmonized System of Classification and Labelling of Chemicals (the GHS). This list contains the vast majority of chemicals currently in HSIS. This list and its detail are regularly updated by Work Safe Australia. The model Work Health and Safety (WHS) Regulations require chemicals to be classified in accordance with the Globally Harmonised System of Classification and Labelling of Chemicals (GHS). However transitional arrangements allow use of classification information in HSIS derived from the Approved Criteria until the 31 December 2016.
  • toxin chemical structure pubchem
  • FORMULA: HNO3
  • DATA SOURCES: DATA SOURCES: ARTICLE 4 | T3DB | PubChem | FDA Indirect Food Additives | EPA USA - Pesticide Inerts | Safe Work Australia - Hazardous Substances Information System (HSIS)
  • LAST UPDATE: 28/04/2018

  Health Associations

Mostly focused on Health Implications of Long Term Exposure to this substance

  • SYMPTOMS: 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.
  • POSSIBLE HEALTH CONSEQUENCES: 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. | 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)
  • ACTION OF TOXIN: 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. | Nitrite causes the autocatalytic oxidation of oxyhemoglobin to hydrogen peroxide and methemoglobin. This elevation of methemoglobin levels is a condition known as methemoglobinemia, and is characterized by tissue hypoxia, as methemoglobin cannot bind oxygen. (A2450, L1613)
  • TOXIN SITES OF ACTION IN CELL: "Cytoplasm", "Extracellular"
  • Additional Exposure Routes: 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.

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  Exposure Routes

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