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.
UN 3189 At a Glance
UN 3189 (Metal powder, self-heating) is listed as DOT Class 4 Spontaneously Combustible and is assigned to ERG Guide 135. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
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.