UN 3189 — Metal powder, self-heating, n.o.s.
Placard: Spontaneously Combustible. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Metal powder, self-heating, n.o.s. is a broad self-heating solid entry. Product identity, packaging and temperature history control the response.
Hazard overview: The main risk is spontaneous heat buildup leading to ignition, toxic smoke, re-ignition or container failure.
Response guidance: Isolate, keep away from combustibles and moisture, monitor for heating, and use dry media unless SDS approves another method.
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 3189 is regulated for transport under its proper shipping name, hazard class 4 and ERG Guide 135. 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 3189 Quick Details
Common Hazards of UN 3189
- Self-heating solid; may generate heat and ignite when exposed to air, moisture or contamination.
- Fire can develop without an outside ignition source if heat is not dissipated.
- Burning material may produce dense irritating, toxic or corrosive smoke.
- Water compatibility varies; water may worsen reaction or spread hot material.
- Containers may rupture when heated.
- Re-ignition is possible after apparent extinguishment.
- Because this is an n.o.s. entry, exact SDS data controls final tactics.
Chemical Identity & Physical Properties
Fine metallic powder, color varies by metal type (gray, silver, black). Odorless. Solid particulate at room temperature that may spontaneously heat when exposed to air or moisture.
| Also known as | self-heating metal powderpyrophoric metal powderreactive metal powdercombustible metal fines |
| Appearance | Fine metallic powder, color varies by metal type (gray, silver, black). Odorless. Solid particulate at room temperature that may spontaneously heat when exposed to air or moisture. |
| Flash Point | Not applicable (self-heating solid) |
| Boiling Point | Not applicable (varies by metal composition) |
| Vapor Density | Not applicable (solid powder) |
| Water Reactivity | Variable; avoid water or moisture until exact material compatibility is confirmed |
Fireground Response Guidance — UN 3189
Extinguishing Media
PPE Requirements
Use SCBA and chemical protective clothing; upgrade protection for toxic, corrosive or unknown vapor conditions.
Isolation & Evacuation
First Actions for a UN 3189 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.
- Separate from combustibles, moisture and ignition sources while monitoring for heat buildup.
- 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 3189 — Metal powder, self-heating, 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.