☣️ UN 3331 • CLASS 7
UN 3331 — Radioactive material, transported under special arrangement, fissile
Placard: Radioactive. ERG Guide 165. 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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UN 3331 Quick Details
UN 3331
Product name: Radioactive material, transported under special arrangement, fissile
DOT Class: 7
Placard type: Radioactive
ERG Guide: 165 (check current ERG)
Initial isolation: ERG 165: isolate 25m all directions initially; if package damaged or contents released, isolate 80m all directions and consult radiation authority immediately; evacuate area if fire involves packages
Common Hazards of UN 3331
- Radiation presents minimal risk to transport workers, emergency response personnel and the public during
- Undamaged packages are safe. Contents of damaged packages may cause higher external radiation exposure,
- Type AF or IF packages, identified by package markings, do not contain life-threatening amounts of material.
- Type B(U)F, B(M)F and CF packages (identified by markings on packages or shipping papers) contain potentially
- The rarely occurring "Special Arrangement" shipments may be of Type AF, BF or CF packages. Package type
- The transport index (TI) shown on labels or a shipping paper might not indicate the radiation level at one meter
- Some radioactive materials cannot be detected by commonly available instruments.
- Water from cargo fire control is not expected to cause pollution.
Chemical Identity & Physical Properties
| Also known as | Fissile radioactive materialSpecial arrangement fissile materialType AF fissile packageType IF fissile package |
| Appearance | Variable physical form depending on specific fissile isotope and packaging; may be solid metal, oxide powder, or solution; packages are specially designed and approved for fissile material transport. |
| Flash Point | Not applicable (radioactive material) |
| Boiling Point | Not applicable (variable depending on isotope form) |
| Vapor Density | Not applicable (variable depending on isotope form) |
| Water Reactivity | Variable depending on specific isotope; some fissile materials may react with water or moisture; follow package-specific handling instructions |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3331
Extinguishing Media
Not applicable for radiation hazard; use appropriate extinguishing media for any secondary fire involving packaging materials
PPE Requirements
⚠️ Radiation detection equipment required; dosimeters mandatory; Level C minimum for undamaged packages with monitoring; Level B with SCBA if package damage suspected; follow ALARA principles
Isolation & Evacuation
ERG 165: isolate 25m all directions initially; if package damaged or contents released, isolate 80m all directions and consult radiation authority immediately; evacuate area if fire involves packages
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 165).
First Actions for a UN 3331 Incident
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not
- Priorities for rescue, life-saving, first aid, fire control and other hazards are higher than the priority for
- Radiation Authority must be notified of accident conditions. Radiation Authority is usually responsible for
- Stay upwind, uphill and/or upstream.
- Keep unauthorized personnel away.
- Detain or isolate uninjured persons or equipment suspected to be contaminated; delay decontamination and
- Isolate spill or leak area for at least 25 meters (75 feet) in all directions.
- Consider initial downwind evacuation for at least 100 meters (330 feet).
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📋 Copy & Share Field Card
UN 3331 — Radioactive material, transported underHAZMAT RADIO NOTE — UN 3331
Product: Radioactive material, transported under special arrangement, fissile
Class 7 / Radioactive / ERG 165
PPE: Radiation detection equipment required; dosimeters mandatory; Level C minimum for undamaged packages with monitoring; Level B with SCBA if package damage suspected; follow ALARA principles
ISOLATION: ERG 165: isolate 25m all directions initially; if package damaged or contents released, isolate 80m all directions and consult radiation authority immediately; evacuate area if fire involves packages
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 3331 — Radioactive material, transported under special arrangement, fissile
Class: 7 | Placard: Radioactive | ERG Guide: 165
Appearance: Variable physical form depending on specific fissile isotope and packaging; may be solid metal, oxide powder, or solution; packages are specially designed and approved for fissile material transport.
Water Reactivity: Variable depending on specific isotope; some fissile materials may react with water or moisture; follow package-specific handling instructions
Extinguishing: Not applicable for radiation hazard; use appropriate extinguishing media for any secondary fire involving packaging materials
PPE: Radiation detection equipment required; dosimeters mandatory; Level C minimum for undamaged packages with monitoring; Level B with SCBA if package damage suspected; follow ALARA principles
Isolation: ERG 165: isolate 25m all directions initially; if package damaged or contents released, isolate 80m all directions and consult radiation authority immediately; evacuate area if fire involves packages
— Key Hazards —
• Radiation presents minimal risk to transport workers, emergency response personnel and the public during
• Undamaged packages are safe. Contents of damaged packages may cause higher external radiation exposure,
• Type AF or IF packages, identified by package markings, do not contain life-threatening amounts of material.
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not
• Priorities for rescue, life-saving, first aid, fire control and other hazards are higher than the priority for
• Radiation Authority must be notified of accident conditions. Radiation Authority is usually responsible for
• Stay upwind, uphill and/or upstream.
SOURCE: allfirefighter.com/hazmat/un/3331 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3331 Radioactive material, transported under special arrangement, fissile Cls7 ERG165 | allfirefighter.com/hazmat/un/3331SMS / 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/3331
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Frequently Asked Questions about UN 3331
Radiation presents minimal risk to transport workers, emergency response personnel and the public during Undamaged packages are safe. Contents of damaged packages may cause higher external radiation exposure, Type AF or IF packages, identified by package markings, do not contain life-threatening amounts of material. Type B(U)F, B(M)F and CF packages (identified by markings on packages or shipping papers) contain potentially The rarely occurring "Special Arrangement" shipments may be of Type AF, BF or CF packages. Package type The transport index (TI) shown on labels or a shipping paper might not indicate the radiation level at one meter Some radioactive materials cannot be detected by commonly available instruments. Water from cargo fire control is not expected to cause pollution.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not Priorities for rescue, life-saving, first aid, fire control and other hazards are higher than the priority for Radiation Authority must be notified of accident conditions. Radiation Authority is usually responsible for
Radiation detection equipment required; dosimeters mandatory; Level C minimum for undamaged packages with monitoring; Level B with SCBA if package damage suspected; follow ALARA principles
Water reactivity: Variable depending on specific isotope; some fissile materials may react with water or moisture; follow package-specific handling instructions. Recommended extinguishing: Not applicable for radiation hazard; use appropriate extinguishing media for any secondary fire involving packaging materials.
ERG Guide 165 recommendation: ERG 165: isolate 25m all directions initially; if package damaged or contents released, isolate 80m all directions and consult radiation authority immediately; evacuate area if fire involves packages
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 165 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.