UN 1942 — Ammonium nitrate, with not more than 0.2% combustible substances
Placard: Oxidizer. ERG Guide 140. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1942 is Ammonium nitrate, with not more than 0.2% combustible substances, a hazardous material assigned to ERG Guide 140. Responders should verify the exact product with shipping papers, package markings and SDS before close action.
Hazard overview: UN 1942 presents hazards that depend on formulation, packaging and incident conditions. Use ERG, SDS and incident command to set isolation, PPE and control actions.
Response guidance: For a UN 1942 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 140. Establish incident command, isolate the area, stay upwind, control ignition or incompatibility hazards, prevent runoff or vapor spread and choose entry/fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1942 should emphasize exposure routes, air monitoring, PPE selection, decontamination, runoff containment and ERG/SDS verification. Use ERG 140, SDS and local SOP.
Regulatory context: Ammonium nitrate, with not more than 0.2% combustible substances is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by formulation, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Ammonium nitrate, with not more than 0.2% combustible substances should be stored in tightly closed compatible containers in a secure, cool, dry, well-ventilated hazardous-material area according to SDS and local procedures.
UN 1942 Quick Details
Common Hazards of UN 1942
- Hazards depend on the exact product, packaging and incident conditions.
- Verify the material using shipping papers, labels and SDS before close action.
- Fire may produce irritating or toxic smoke.
- Containers may fail or rupture when heated.
Chemical Identity & Physical Properties
White to gray crystalline solid or pellets. Odorless. Hygroscopic (absorbs moisture from air).
| Also known as | Nitric acid ammonium saltNorway saltpeterAmmonium saltpeterAN fertilizer |
| CAS Number | 6484-52-2 |
| Appearance | White to gray crystalline solid or pellets. Odorless. Hygroscopic (absorbs moisture from air). |
| Flash Point | Not applicable (oxidizer, non-combustible) |
| Boiling Point | Decomposes at 210C (410F) before boiling |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Dissolves readily in water, no violent reaction. Solutions may be acidic. |
Fireground Response Guidance — UN 1942
Extinguishing Media
PPE Requirements
Use protective equipment selected from SDS, monitoring results and incident command.
Isolation & Evacuation
First Actions for a UN 1942 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, fumes, dust, mist, smoke or gas and avoid skin or eye contact.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or leak area and expand the perimeter if vapor, dust, fire involvement, gas accumulation or unknown concentration is present.
- Use ERG Guide 140, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1942 — Ammonium nitrate, with not more than 0.2Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.