UN 2004 — Magnesium diamide
Placard: Spontaneously Combustible. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2004 is Magnesium diamide, a spontaneously combustible and moisture-reactive solid assigned to ERG Guide 135. Moisture can release heat and ammonia, so dry handling is essential.
Hazard overview: SPONTANEOUSLY COMBUSTIBLE and water-reactive solid; may ignite on contact with moist air or moisture. Reacts with water or moist air, releasing heat and ammonia gas. May burn rapidly and re-ignite after apparent extinguishment.
Response guidance: For a UN 2004 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 135. Establish incident command, isolate the area, stay upwind, prevent incompatible contact, control runoff or dust spread and base entry/fire-control actions on monitoring and local SOP.
Firefighter training notes: Training for UN 2004 should emphasize moisture exclusion, dry-agent/Class D tactics where appropriate, hydrogen or ammonia gas generation, re-ignition and dust control. Use ERG 135, SDS and local SOP.
Regulatory context: Magnesium diamide is regulated as a hazardous material for transportation and emergency response purposes. Storage, workplace exposure, emergency planning, spill reporting, waste handling and environmental requirements vary by exact product, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, container markings and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Magnesium diamide should be stored dry in compatible sealed containers away from water, moisture, oxidizers, acids where incompatible, ignition sources and unauthorized access. Keep compatible dry extinguishing media available and prevent dust generation.
UN 2004 Quick Details
Common Hazards of UN 2004
- SPONTANEOUSLY COMBUSTIBLE and water-reactive solid; may ignite on contact with moist air or moisture.
- Reacts with water or moist air, releasing heat and ammonia gas.
- May burn rapidly and re-ignite after apparent extinguishment.
- Water, foam or CO2 may worsen reaction or spread burning material.
- Dust or decomposition products may irritate eyes, skin and respiratory tissue.
- Containers may rupture or fail when heated.
- Keep material dry and avoid dust generation.
Chemical Identity & Physical Properties
White to grayish-white crystalline powder or granular solid. May have an ammonia-like odor, especially when exposed to moisture. Solid at room temperature.
| Also known as | Magnesium diamideMagnesium amideDiaminomagnesiumMagnesium nitride hydride |
| CAS Number | 7803-54-5 |
| Appearance | White to grayish-white crystalline powder or granular solid. May have an ammonia-like odor, especially when exposed to moisture. Solid at room temperature. |
| Flash Point | Not applicable (spontaneously flammable solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts violently with water, liberating ammonia and heat. Do not use water directly on material. |
Fireground Response Guidance — UN 2004
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for smoke, dust or fire exposure. Wear fire-resistant and chemical-resistant protection selected from SDS; avoid moisture contamination and dust generation.
Isolation & Evacuation
First Actions for a UN 2004 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 dust, vapor, fumes, mist or smoke and avoid skin or eye contact.
- Keep water, foam and moisture away from the material unless incident command confirms a compatible control use.
- Do not touch damaged containers or 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 release area and expand the perimeter for fire involvement, water reaction, vapor generation, dust spread or unknown product identity.
- Use ERG Guide 135, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 2004 — Magnesium diamideUse 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.