UN 1326 — Hafnium powder, wetted with not less than 25% water
Placard: Flammable Solid. ERG Guide 170. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1326 is Hafnium powder, wetted with not less than 25% water, a Class 4 flammable metal solid assigned to ERG Guide 170. The main concerns are dust ignition, intense metal fire, re-ignition and incompatibility with common extinguishing agents.
Hazard overview: UN 1326 presents flammable metal powder and dust hazards. Fine particles can ignite from friction, heat or sparks, burn intensely and may react dangerously with water or incompatible fire agents, especially if dry or dispersed.
Response guidance: For a UN 1326 incident, responders should confirm the product using shipping papers, container markings, SDS and ERG Guide 170. Establish incident command, isolate the area, stay upwind and uphill, remove ignition sources when safe, keep vapors, dust or runoff out of drains where relevant, and use compatible fire-control agents from a protected position.
Firefighter training notes: Training for UN 1326 should emphasize metal fire behavior, dust cloud prevention, incompatible extinguishing agents, re-ignition, dry-agent application and safe standoff. Common errors include using water or foam on burning metal, disturbing powder and underestimating metal oxide fumes. Use ERG 170, SDS and metal-fire SOP.
Regulatory context: Hafnium powder, wetted with not less than 25% water is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by formulation, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Hafnium powder, wetted with not less than 25% water should be stored in compatible containers away from heat, ignition sources, oxidizers, moisture where incompatible and physical damage. Prevent dust release, container damage and contact with incompatible extinguishing agents or water-reactive conditions as described in the SDS.
UN 1326 Quick Details
Common Hazards of UN 1326
- FLAMMABLE metal powder or reactive metal solid; may be ignited by heat, sparks, friction or flames.
- Dusts or fine particles may burn rapidly or form explosive mixtures in air.
- Metal fires can burn with intense heat and may re-ignite after apparent extinguishment.
- Wetting reduces pyrophoric hazard, but dry hafnium powder can ignite and react with water or air under severe conditions.
- Metal oxide fumes from fire may be hazardous to breathe.
- Containers may rupture or explode when heated.
- Avoid creating dust clouds or spreading powder during response.
Chemical Identity & Physical Properties
Gray to silver metallic powder, odorless. Shipped wetted with minimum 25% water to reduce pyrophoric hazard.
| Also known as | Hafnium metal powderHafnium powder wettedHf powderHafnium flammable solid |
| CAS Number | 7440-58-6 |
| Appearance | Gray to silver metallic powder, odorless. Shipped wetted with minimum 25% water to reduce pyrophoric hazard. |
| Flash Point | Not applicable (pyrophoric metal powder when dry) |
| Boiling Point | 4603C (8317F) |
| Vapor Density | Not applicable (solid metal) |
| Water Reactivity | Reacts with water when dry, generating heat and hydrogen gas. Wetted form designed to prevent ignition. |
Fireground Response Guidance — UN 1326
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for fire, smoke or dust exposure. Protective clothing, gloves and eye/face protection should follow SDS and metal-fire SOP; PPE does not protect against violent metal fire, dust explosion or container rupture hazards.
Isolation & Evacuation
First Actions for a UN 1326 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Eliminate ignition sources if it is safe to do so.
- Do not create dust clouds or disturb spilled powder unless properly trained and equipped.
- Keep water, foam, CO2 and halogenated agents away from burning or reactive metal unless incident command confirms compatibility.
- Use dry Class D agents, dry sand or other compatible dry media when directed by incident command.
- Isolate the spill or fire area and expand the perimeter if metal powder is burning, dry or dispersed.
- Use ERG Guide 170, shipping papers, SDS and hazmat/metal-fire SOP for protective actions and entry decisions.
📋 Copy & Share Field Card
UN 1326 — Hafnium powder, wetted with not less thaUse 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.