{
 "license": "CC BY 4.0 — Tremon Solutions, https://www.tremon.nl/gases/nh3",
 "generated": "2026-09-17",
 "key": "nh3",
 "name": "Ammonia",
 "formula": "NH₃",
 "formula_plain": "H3N",
 "iupac": "azane",
 "synonyms": [
  "Anhydrous ammonia",
  "Aqua ammonia",
  "Aqueous ammonia [Note: Often used in an aqueous solution.]"
 ],
 "cas": "7664-41-7",
 "ec_number": "231-635-3",
 "un_number": "1005",
 "un_shipping_name": "Ammonia, anhydrous",
 "transport_class": "2.3 (Toxic gases)",
 "pubchem_cid": 222,
 "molar_mass_g_mol": 17.03,
 "mg_m3_per_ppm_20c": 0.708,
 "boiling_point_c": -33.4,
 "sublimation_point_c": null,
 "melting_point_c": -77.7,
 "critical_temp_c": 132.4,
 "critical_pressure_bar": 112.8,
 "vapour_pressure_bar": 8.574,
 "vapour_pressure_at_c": 20.0,
 "density_gas_kg_m3": 0.7714,
 "density_condition": "0 °C, 1013 mbar",
 "relative_density_air": 0.6,
 "solubility_water": "531 g/l at 20 °C",
 "appearance": "gas liquefied under pressure, colourless, pungent suffocating odour",
 "odour": "pungent suffocating odour",
 "chemical_character": [
  "Flammable gas.",
  "Ammonia gas burns only at high concentrations, high temperature and a strong energy source. Without heat input the flame extinguishes immediately.",
  "Freely soluble in water.",
  "Aqueous solution reacts alkaline.",
  "Gas is lighter than air.",
  "Acute or chronic health hazards result from the substance."
 ],
 "hazard_class": "toxic + corrosive + flammable",
 "ghs_classification": [
  "Flammable gases, Category 2; H221",
  "Gases under pressure, liquefied gas; H280",
  "Acute toxicity, Category 3, inhalation; H331",
  "Skin corrosion, Category 1B; H314",
  "Serious eye damage, Category 1; H318",
  "Hazardous to the aquatic environment, Acute Category 1; H400",
  "Hazardous to the aquatic environment, Chronic Category 2; H411"
 ],
 "ghs_signal_word": "Danger",
 "ghs_hazard_statements": [
  "H221: Flammable gas.",
  "H280: Contains gas under pressure; may explode if heated.",
  "H314: Causes severe skin burns and eye damage.",
  "H331: Toxic if inhaled.",
  "H410: Very toxic to aquatic life with long lasting effects."
 ],
 "euh_statements": [
  "EUH071: Corrosive to the respiratory tract."
 ],
 "nfpa704": {
  "health": 3,
  "flammability": 1,
  "instability": 0,
  "special": null
 },
 "lel_vol_pct": 14.0,
 "uel_vol_pct": 32.5,
 "autoignition_c": 630.0,
 "temperature_class": "T1",
 "explosion_group": "IIA",
 "eu_ioelv": {
  "twa_8h_ppm": 20.0,
  "twa_8h_mg_m3": 14.0,
  "stel_15min_ppm": 50.85,
  "stel_15min_mg_m3": 36.0,
  "directive": "Directive 2000/39/EC"
 },
 "de_agw": {
  "twa_ppm": 20.0,
  "twa_mg_m3": 14.0,
  "source": "TRGS 900 via GESTIS"
 },
 "nl_grenswaarde": {
  "note": "Netherlands: wettelijke grenswaarden (Arboregeling, bijlage XIII) — check the SER grenswaarden database (https://www.ser.nl/nl/thema/arbeidsomstandigheden/grenswaarden) for the current legal value; EU IOELVs are transposed into it."
 },
 "niosh_rel": {
  "twa_ppm": 25.0,
  "stel_or_ceiling_ppm": 35.0,
  "raw": "TWA 25 ppm (18 mg/m3) ST 35 ppm (27 mg/m3)"
 },
 "osha_pel": "TWA 50 ppm (35 mg/m3) See Appendix G",
 "idlh_ppm": 300.0,
 "idlh_raw": "300 ppm",
 "gwp100": {
  "ar4": null,
  "ar6": null,
  "eu_fgas_2024_573_annex": null
 },
 "atmospheric_lifetime_years": null,
 "odp": 0,
 "gwp_note": null,
 "seveso_named": true,
 "health_effects": "Corrosive alkaline gas: severe eye and airway irritation from 20–30 ppm, intolerable ~300 ppm (IDLH), laryngeal/pulmonary oedema and death from ~1700 ppm. Liquid splash causes frostbite plus chemical burn. Odour threshold ~5 ppm gives warning.",
 "main_toxic_effects_gestis": "Acute: \nSeverely irritative/corrosive effects to the eyes, respiratory tract and skin,\ndanger of severe damage to the eyes and respiratory tract\nChronic: \nChronic respiratory irritation/respiratory complaints",
 "routes_of_exposure": "Main routes of exposure\nThe main intake pathway for ammonia (A.) is via the respiratory tract.\nRespiratory tract\nOn account of its high solubility in water A. is absorbed mainly in the upper respiratory tract. In the first few minutes almost the entire inhaled amount of A. is retained by the mucous membranes (mainly the nasal mucous membranes).\nThereafter the retained portion sinks rapidly until a status of equilibrium is reached. Among volunteers who were exposed to 500 ppm of A., the retained proportion after 30 minutes amounted to only 4 - 30% (mean value 23%).\nThe respiratory minute volume, which is affected by A. dependent on concentration and length of exposure, has a significant effect on the amount of A. absorbed.\nSkin\nAlthough kinetic data are not available, absorbability via the skin is assumed on account of the known deep-reaching tissue-damaging potential of A. As far as the absorption of toxic doses is concerned, this intake pathway is not accorded any significance.\nGastrointestinal tract\nOral intake of solutions in water is considered possible in principle, but not for A. in water-free, liquid form.\nIn principle, however, systemically relevant doses may be absorbed via the digestive tract.",
 "ir_absorption_band_um": "10.3–10.7 µm (ν₂ umbrella, 932/968 cm⁻¹); 6.1 µm (ν₄); 3.0 µm (N–H stretch)",
 "monitoring": [
  "Electrochemical for 0–100 ppm workplace; NDIR (10.5 µm) or laser for refrigeration plants (0–1 vol%) and process/agricultural monitoring where EC cells die from continuous exposure.",
  "Alarms: 20 ppm (IOELV) pre-alarm, 50 ppm main in refrigeration machine rooms (EN 378 requires detection at 500 ppm max); sensors at ceiling (lighter than air)."
 ],
 "regulation_windows": [
  "Workplace: EU IOELV 20 ppm / STEL 50 ppm (Dir. 2000/39/EC)",
  "EN 378 — refrigerating systems: detectors mandatory in machinery rooms",
  "IED / NEC Directive 2016/2284 — agricultural NH₃ emission ceilings",
  "Seveso III — named substance (50 t / 200 t tiers)"
 ],
 "tremon_products": [
  "TRM-PGA (NH₃ NDIR channel)",
  "TRM-EX (electrochemical)",
  "IR·OEM NH₃ channel"
 ],
 "sources": [
  "https://gestis-database.dguv.de/data?name=001100",
  "https://www.cdc.gov/niosh/npg/npgd0028.html",
  "https://pubchem.ncbi.nlm.nih.gov/compound/222",
  "IPCC AR6 WG1 Ch.7 Supplementary Material, Table 7.SM.7 (https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter07_SM.pdf)",
  "HITRAN/NIST IR band positions (approximate centre of the strongest band used for NDIR; https://hitran.org, https://webbook.nist.gov)"
 ]
}