Ammonia (anhydrous) — properties & hazards overview
Boiling point
−33.3 °C
Flammability (air)
LEL 15% – UEL 28% vol
Auto-ignition
≈ 651 °C
Water solubility
Very high (forms NH₄OH)
Toxicity
caustic inhalation
Flammability
15–28% in air
Chronic risk
respiratory/dermal
Environmental
aquatic toxicity
| Property | Value / Note |
|---|---|
| Chemical formula | NH₃ |
| Molar mass | 17.03 g/mol |
| Physical state (20 °C) | Colourless gas (liquefied under pressure) |
| Boiling / Melting point | −33.3 °C / −77.7 °C |
| Vapour density (air=1) | ~ 0.6 (lighter than air; tends to rise) |
| Odour / threshold | Sharp, pungent / ~ 5 ppm (typical) |
| Water solubility | Very soluble; forms ammonium hydroxide (exothermic) |
| Typical uses | Fertiliser (urea/AS), refrigeration, chemical synthesis (amines, nitric compounds) |
*Values are indicative; always consult the latest SDS/standards for design and safety.