UN 2463 — Aluminum hydride
Placard: Dangerous When Wet. ERG Guide 138. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2463 is Aluminum hydride, a dangerous-when-wet hydride assigned to ERG Guide 138. Moisture can generate hydrogen, heat and ignition.
Hazard overview: DANGEROUS WHEN WET hydride; reacts violently with water or moist air. Water contact produces flammable hydrogen gas and heat, which may cause ignition. Dust or solid may ignite from heat, friction, sparks or moisture.
Response guidance: For UN 2463, isolate the area, stay upwind and use SCBA with specialist hazmat controls. Keep incompatible water/moisture tactics under incident command, use compatible dry or directed agents and watch for re-ignition.
Firefighter training notes: Training for UN 2463 should emphasize reactivity, moisture control, compatible extinguishing media, re-ignition checks, SCBA use, decontamination and runoff control. Use ERG 138, SDS and local SOP.
Regulatory context: Aluminum hydride is regulated as a hazardous material for transport and emergency response. Storage, exposure, spill reporting, waste and fire-code duties depend on quantity, concentration and jurisdiction; verify shipping papers, SDS and local authority requirements.
Storage & handling: Aluminum hydride should be stored dry in sealed compatible containers away from water, moisture, acids, oxidizers/reducing agents where incompatible, heat and ignition sources. Keep compatible dry media available.
UN 2463 Quick Details
Common Hazards of UN 2463
- DANGEROUS WHEN WET hydride; reacts violently with water or moist air.
- Water contact produces flammable hydrogen gas and heat, which may cause ignition.
- Dust or solid may ignite from heat, friction, sparks or moisture.
- May re-ignite after apparent extinguishment.
- Water, foam and CO2 can worsen the reaction or spread burning material.
- Runoff may create fire, explosion and caustic contamination hazards.
- Containers may rupture when heated or contaminated with moisture.
Chemical Identity & Physical Properties
White to gray crystalline powder or solid. Odorless. Highly reactive pyrophoric material that may ignite spontaneously in moist air.
| Also known as | Aluminium hydrideAluminum trihydrideAlH3Alane |
| CAS Number | 7784-21-6 |
| Appearance | White to gray crystalline powder or solid. Odorless. Highly reactive pyrophoric material that may ignite spontaneously in moist air. |
| Flash Point | Not applicable (pyrophoric solid - ignites spontaneously in air) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts violently with water, producing flammable hydrogen gas and heat. May ignite spontaneously. Do not use water. |
Fireground Response Guidance — UN 2463
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and dry, compatible protective clothing. Protect against fire, caustic/oxidizer dust and reaction products; exclude moisture from PPE/work area.
Isolation & Evacuation
First Actions for a UN 2463 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.
- Avoid breathing vapor, dust, gas, mist, smoke or fumes and avoid skin or eye contact.
- Keep incompatible water or moisture controls strictly under incident command because reaction or re-ignition hazards are severe.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 138, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2463 — Aluminum hydrideUse 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.