UN 1843 — Ammonium dinitro-o-cresolate, solid
Placard: Toxic. ERG Guide 141. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Ammonium dinitro-o-cresolate is a toxic substance that can accelerate burning when involved in a fire. It is a yellow to orange crystalline solid with a slight phenolic odor.
Hazard overview: These substances will accelerate burning when involved in a fire and may explode from heat or contamination. Prolonged exposure can be hazardous to health.
Response guidance: In case of an emergency, isolate the spill/leak area and evacuate immediately. Use dry chemical, sand, or CO2 to extinguish the fire, and water spray to cool containers from a distance.
UN 1843 Quick Details
Common Hazards of UN 1843
- These substances will accelerate burning when involved in a fire.
- May explode from heat or contamination.
- Some may burn rapidly.
- Some will react explosively with hydrocarbons (fuels).
- May ignite combustibles (wood, paper, oil, clothing, etc.).
- Containers may explode when heated.
- Runoff may create fire or explosion hazard.
- Toxic by ingestion.
Chemical Identity & Physical Properties
Ammonium dinitro-o-cresolate is a yellow to orange crystalline solid with a slight phenolic odor, stable when dry but shock-sensitive when wet or contaminated.
| Also known as | Ammonium 4,6-dinitro-o-cresolateAmmonium 2-methyl-4,6-dinitrophenolateADOCDinitro-o-cresol ammonium salt |
| CAS Number | 2980-64-5 |
| Appearance | Yellow to orange crystalline solid with a slight phenolic odor. Stable when dry but shock-sensitive when wet or contaminated. |
| Flash Point | Not applicable (oxidizing solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Soluble in water; no violent reaction but forms toxic solution |
Fireground Response Guidance — UN 1843
Extinguishing Media
PPE Requirements
Level B minimum with full face SCBA, chemical-resistant gloves and boots are required to handle this substance.
Isolation & Evacuation
First Actions for a UN 1843 Incident
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
- Consider initial downwind evacuation for at least 100 meters (330 feet).
📋 Copy & Share Field Card
UN 1843 — Ammonium dinitro-o-cresolate, solidUse 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.