UN 3182 — Metal hydrides, flammable, n.o.s.
Placard: Flammable Solid. ERG Guide 170. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Metal hydrides, flammable, n.o.s. is a broad entry for reactive hydride solids or suspensions that can generate hydrogen on water contact.
Hazard overview: The critical hazard is water reaction: heat and hydrogen can cause ignition, explosion or rapid fire spread.
Response guidance: Protect from moisture, isolate the area, remove ignition sources, and use only compatible dry extinguishing agents from a safe distance.
Firefighter training notes: Use this page as initial reference only; responders should train from ERG, SDS, department SOPs and product-specific preplans.
Regulatory context: UN 3182 is regulated for transport under its proper shipping name, hazard class 4 and ERG Guide 170. Verify current DOT/PHMSA requirements and shipping papers.
Storage & handling: Store only as permitted by the SDS and applicable code: segregate from incompatible materials, protect packages from heat, damage and moisture, and maintain labels.
UN 3182 Quick Details
Common Hazards of UN 3182
- Water-reactive metal hydrides can release flammable hydrogen and heat.
- Dust or suspended powder may ignite from friction, sparks or static discharge.
- Some shipments may be packed in flammable liquids, adding vapor and flashback hazards.
- Burning metal hydrides can produce intense heat and irritating metal oxide fumes.
- CO2, foam or water may react dangerously with the material.
- Containers may rupture or explode when heated.
- Re-ignition can occur if hot material is exposed to air or moisture.
Chemical Identity & Physical Properties
Typically gray to white crystalline or powdered solids. May be shipped in flammable liquids as suspensions. Odorless in pure form.
| Also known as | Metal hydrides NOSFlammable metal hydridesHydrides of metalsAlkali metal hydridesAlkaline earth metal hydrides |
| Appearance | Typically gray to white crystalline or powdered solids. May be shipped in flammable liquids as suspensions. Odorless in pure form. |
| Flash Point | Not applicable (pyrophoric/water-reactive solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid material) |
| Water Reactivity | Reacts violently or explosively with water, releasing heat and flammable hydrogen gas |
Fireground Response Guidance — UN 3182
Extinguishing Media
PPE Requirements
SCBA and Level B minimum PPE are required; use chemical-resistant clothing and avoid any moisture contact.
Isolation & Evacuation
First Actions for a UN 3182 Incident
- Call 911 and the emergency response number shown on shipping papers.
- Keep unauthorized personnel away and establish an isolation perimeter.
- Stay upwind, uphill and upstream; avoid low areas where vapors or gases may collect.
- Avoid breathing vapors, dust, smoke or decomposition products.
- Do not touch damaged containers or spilled material without appropriate PPE.
- Keep the material completely dry and eliminate ignition sources before any approach.
- Ventilate confined spaces only if trained, equipped and atmospheric monitoring supports entry.
- Use ERG guidance, SDS, labels and shipping papers to confirm the exact hazards before action.
📋 Copy & Share Field Card
UN 3182 — Metal hydrides, flammable, n.o.s.Use 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.