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.
UN 3182 At a Glance
UN 3182 (Metal hydrides, flammable) is listed as DOT Class 4 Flammable Solid and is assigned to ERG Guide 170. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
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.