Water & Air / Compounds / Ammonium nitrate

Ammonium nitrate in water and air: safety profile

Moderate risk

(People-specific data is limited; this page draws from human adult context.) Ammonium nitrate is primarily used as a nitrogen fertilizer (34% N). Moderate acute oral toxicity: LD50 rat ~2217 mg/kg. Respiratory irritant as dust; prolonged inhalation of dust in occupational settings causes methemoglobinemia. Major explosion hazard when heated, confined, or contaminated with fuel oil (ANFO). Notable industrial disasters: Texas City (1947, 581 dead), Toulouse (2001, 31 dead), Beirut (2020, 218 dead). Chronic exposure: thyroid effects via nitrate interference with iodide uptake (sodium-iodide symporter inhibition).

What is ammonium nitrate?

Also known as: AN, Nitram, Ammonium saltpeter, Nitramoncal.

CAS number
6484-52-2
Molecular formula
H4N2O3
Molecular weight
80.04 g/mol
SMILES
[NH4+].[N+](=O)([O-])[O-]
PubChem CID
22985

Risk for people

Moderate risk

Ammonium nitrate is primarily used as a nitrogen fertilizer (34% N). Moderate acute oral toxicity: LD50 rat ~2217 mg/kg. Respiratory irritant as dust; prolonged inhalation of dust in occupational settings causes methemoglobinemia. Major explosion hazard when heated, confined, or contaminated with fuel oil (ANFO). Notable industrial disasters: Texas City (1947, 581 dead), Toulouse (2001, 31 dead), Beirut (2020, 218 dead). Chronic exposure: thyroid effects via nitrate interference with iodide uptake (sodium-iodide symporter inhibition).

Regulatory consensus

2 regulatory and scientific bodies have classified Ammonium nitrate. The classifications differ — that's the data.

AgencyYearClassificationNotes
EU2019Oxidising Solid Cat. 3 (H272); regulated under REACH Annex XVII entry 58 and EU Regulation 2019/1148 (precursor explosives)
DHS2007Chemical Facility Anti-Terrorism Standards (CFATS) — Chemicals of Interest

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter ammonium nitrate

  • Agriculture
  • Water
  • Industrial
  • Cold Packs

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Ammonium nitrate:

  • Calcium ammonium nitrate (CAN)
    Trade-offs: Lower N content (26-28% vs 34%). Reduced explosion risk due to calcium carbonate dilution. Preferred in EU for security reasons.
    Relative cost: Similar (per unit area)
  • Urea (CO(NH2)2)
    Trade-offs: Higher N content (46%) but volatilization losses. No explosion risk. Requires urease inhibitors for efficiency.
    Relative cost: Lower per unit N

Frequently asked questions

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See Ammonium nitrate in the water app

Look up products containing ammonium nitrate, compare to alternatives, and explore the full data record.

Open in water View raw API data

Sources (2)
  1. ATSDR Toxicological Profile — Nitrate and Nitrite — atsdr
  2. EPA IRIS — Nitrate (CASRN 14797-55-8) — epa

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →