☣️ UN 2545 • CLASS 4
Hafnium powder, dry
Placard: Spontaneously Combustible. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.
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Quick details
UN 2545
Class: 4
Placard type: Spontaneously Combustible
ERG: Guide 135 (check current ERG)
Isolation: ERG 135: isolate 25-50m all directions; consider evacuation 100-300m downwind if fire
Chemical & Response Details
| Also known as | Hafnium metal powderHafnium dustHf powder |
| CAS Number | 7440-58-6 |
| Appearance | Gray to silver-gray metallic powder, odorless. Pyrophoric when finely divided. |
| Flash Point | Not applicable (spontaneously combustible metal powder) |
| Boiling Point | 4603C (8317F) |
| Vapor Density | Not applicable (solid metal) |
| Water Reactivity | Reacts with moisture/water, especially when finely divided, generating heat and potentially igniting |
| Extinguishing | Dry sand, dry chemical, soda ash. DO NOT use water, foam, or CO2 |
| PPE | ⚠️ Level B minimum; SCBA required; fire-resistant clothing for fire conditions |
| Isolation | ERG 135: isolate 25-50m all directions; consider evacuation 100-300m downwind if fire |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- Flammable/combustible material.
- May ignite on contact with moist air or moisture.
- May burn rapidly with flare-burning effect.
- Some react vigorously or explosively on contact with water.
- Some may decompose explosively when heated or involved in a fire.
- May re-ignite after fire is extinguished.
- Runoff may create fire or explosion hazard.
- Containers may explode when heated.
First actions (field-minded)
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Stay upwind, uphill and/or upstream.
- Keep unauthorized personnel away.
- Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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UN 2545 — Hafnium powder, dry HAZMAT RADIO NOTE — UN 2545
Product: Hafnium powder, dry
Class 4 / Spontaneously Combustible / ERG 135
PPE: Level B minimum; SCBA required; fire-resistant clothing for fire conditions
ISOLATION: ERG 135: isolate 25-50m all directions; consider evacuation 100-300m downwind if fire
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 2545 — Hafnium powder, dry
Class: 4 | Placard: Spontaneously Combustible | ERG Guide: 135
Appearance: Gray to silver-gray metallic powder, odorless. Pyrophoric when finely divided.
Water Reactivity: Reacts with moisture/water, especially when finely divided, generating heat and potentially igniting
Extinguishing: Dry sand, dry chemical, soda ash. DO NOT use water, foam, or CO2
PPE: Level B minimum; SCBA required; fire-resistant clothing for fire conditions
Isolation: ERG 135: isolate 25-50m all directions; consider evacuation 100-300m downwind if fire
— Key Hazards —
• Flammable/combustible material.
• May ignite on contact with moist air or moisture.
• May burn rapidly with flare-burning effect.
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Stay upwind, uphill and/or upstream.
• Keep unauthorized personnel away.
• Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
SOURCE: allfirefighter.com/hazmat/un/2545 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2545 Hafnium powder, dry Cls4 ERG135 | ERG 135: isolate 25-50m all directions; consider evacuation 100-300m downwind if | allfirefighter.com/hazmat/un/2545SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS. Includes link to full page.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/2545
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FAQ
Flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Stay upwind, uphill and/or upstream. Keep unauthorized personnel away.
Level B minimum; SCBA required; fire-resistant clothing for fire conditions
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 135 and your department SOP/SOG for incident-specific protective actions.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles. This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.