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.
UN 3331 is Radioactive material, transported under special arrangement, fissile, a fissile radioactive package assigned to ERG Guide 165. Undamaged packages are engineered for containment; damaged packages require radiation authority control.
Hazard overview: RADIOACTIVE fissile package; undamaged packages are designed to maintain shielding, containment and criticality safety. Damaged packages may increase external radiation exposure and create contamination-control concerns. Fissile contents require radiation authority guidance because package geometry, moderation and shielding matter.
Response guidance: For UN 3331, protect life safety first, isolate damaged packages and notify radiation authority. Limit handling, control runoff/debris and use monitoring with ERG 165.
Firefighter training notes: Training for UN 3331 should emphasize package recognition, radiation authority notification, dosimetry/survey use, contamination control, time-distance-shielding and life-safety priority. Use ERG 165 and radiation SOP.
Regulatory context: Radioactive material, transported under special arrangement, fissile is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, package type, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Radioactive material, transported under special arrangement, fissile should remain in approved radioactive material packages protected from damage, fire, unauthorized access and contamination spread. Follow radiation authority, carrier and package-certificate requirements.
UN 3331 Quick Details
Common Hazards of UN 3331
- RADIOACTIVE fissile package; undamaged packages are designed to maintain shielding, containment and criticality safety.
- Damaged packages may increase external radiation exposure and create contamination-control concerns.
- Fissile contents require radiation authority guidance because package geometry, moderation and shielding matter.
- Transport index and package labels may not fully describe radiation level at every point after damage.
- Some radioactive contents may not be detected by common instruments without proper survey equipment.
- Fire may damage packaging and create contaminated debris or runoff-control issues.
- Life safety, rescue and fire control remain priorities while limiting time, maximizing distance and using shielding.
Chemical Identity & Physical Properties
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.
| 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 |
Fireground Response Guidance — UN 3331
Extinguishing Media
PPE Requirements
Use PPE for the dominant hazard plus dosimetry and radiation monitoring. For fire, use SCBA and turnout gear; minimize time, maximize distance and use shielding.
Isolation & Evacuation
First Actions for a UN 3331 Incident
- Call 911 and notify the radiation authority according to local procedures.
- Protect life safety first while minimizing time near damaged packages.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind, uphill and upstream of smoke, runoff or damaged contents.
- Do not handle damaged packages or loose contents without proper training and radiation monitoring.
- Detain potentially contaminated people or equipment for assessment without delaying urgent medical care.
- Use ERG Guide 165, package labels, shipping papers and radiation monitoring to guide isolation, evacuation and cleanup.
📋 Copy & Share Field Card
UN 3331 — Radioactive material, transported underUse 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.