UN 2835 — Sodium aluminum hydride
Placard: Dangerous When Wet. ERG Guide 138. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2835 is Sodium aluminum hydride, a dangerous-when-wet hydride assigned to ERG Guide 138. Water can release 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 2835, isolate the area, exclude water/moisture and use SCBA. Use only compatible dry media, watch for re-ignition and verify tactics with SDS and ERG 138.
Firefighter training notes: Training for UN 2835 should emphasize water/moisture exclusion, dry-media tactics, re-ignition checks, gas monitoring, SCBA use and runoff control. Use ERG 138, SDS and local SOP.
Regulatory context: Sodium 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: Sodium aluminum hydride should be stored dry in sealed compatible containers away from water, moisture, acids, oxidizers and ignition sources. Keep compatible dry media available.
UN 2835 Quick Details
Common Hazards of UN 2835
- 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 grayish-white crystalline powder or granular solid. Odorless. Stable when dry but extremely reactive with moisture.
| Also known as | Sodium aluminium hydrideSodium tetrahydroaluminateSAHSodium alanate |
| CAS Number | 13770-96-2 |
| Appearance | White to grayish-white crystalline powder or granular solid. Odorless. Stable when dry but extremely reactive with moisture. |
| Flash Point | Not applicable (ignites spontaneously with water/moist air) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid material) |
| Water Reactivity | Reacts violently with water producing flammable hydrogen gas and heat; may ignite spontaneously |
Fireground Response Guidance — UN 2835
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and dry compatible protective clothing. Protect against fire, caustic/reactive dust and toxic decomposition products; exclude moisture.
Isolation & Evacuation
First Actions for a UN 2835 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, mist, smoke or fumes and avoid skin or eye contact.
- Keep water or moisture contact controlled because reaction or re-ignition hazards may be severe.
- 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 138, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2835 — Sodium 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.