UN 2956 — 5-tert-Butyl-2,4,6-trinitrom- xylene
Placard: Flammable Solid. ERG Guide 149. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2956 is 5-tert-Butyl-2,4,6-trinitrom- xylene, a flammable energetic nitroaromatic solid assigned to ERG Guide 149. Heat, friction and decomposition risks require control.
Hazard overview: FLAMMABLE nitroaromatic solid; heat, friction, sparks or contamination may ignite it. May decompose violently if heated, confined or involved in fire. Dust may form explosive mixtures in air and increase sensitivity.
Response guidance: For UN 2956, isolate the area, avoid dust/friction and use SCBA. Use only compatible dry media, watch for re-ignition or violent decomposition and follow SDS/ERG 149.
Firefighter training notes: Training for UN 2956 should emphasize dry-media tactics, moisture/friction control, re-ignition, remote operations, SCBA use and runoff/debris control. Use ERG 149, SDS and local SOP.
Regulatory context: 5-tert-Butyl-2,4,6-trinitrom- xylene is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: 5-tert-Butyl-2,4,6-trinitrom- xylene should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 2956 Quick Details
Common Hazards of UN 2956
- FLAMMABLE nitroaromatic solid; heat, friction, sparks or contamination may ignite it.
- May decompose violently if heated, confined or involved in fire.
- Dust may form explosive mixtures in air and increase sensitivity.
- Burning may be intense and may produce large volumes of toxic gases.
- Fire may produce nitrogen oxides and irritating/toxic aromatic smoke.
- Runoff or residues may carry toxic energetic material contamination.
- Avoid impact, friction, dust generation and unnecessary handling.
Chemical Identity & Physical Properties
Yellow to white crystalline solid with a musk-like odor. Exists as crystals or powder at room temperature.
| Also known as | Musk xylene5-tert-Butyl-2,4,6-trinitro-m-xyleneMusk xylol1-tert-Butyl-3,5-dimethyl-2,4,6-trinitrobenzene |
| CAS Number | 81-15-2 |
| Appearance | Yellow to white crystalline solid with a musk-like odor. Exists as crystals or powder at room temperature. |
| Flash Point | Not applicable (explosive solid) |
| Boiling Point | Decomposes at approximately 205C (401F) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Insoluble in water; no significant reaction with water |
Fireground Response Guidance — UN 2956
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for fire, dust or smoke. Wear flame/chemical protection and avoid dust, friction and incompatible media.
Isolation & Evacuation
First Actions for a UN 2956 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind, uphill and upstream.
- Eliminate ignition sources if this can be done safely.
- Avoid breathing vapor, dust, gas, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated liquid, dust, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 149, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2956 — 5-tert-Butyl-2,4,6-trinitrom- xyleneUse 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.