☣️ UN 2977 • CLASS 7
Radioactive material, uranium hexafluoride, fissile
Placard: Radioactive. 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 2977
Class: 7
Placard type: Radioactive
ERG: Guide 166 (check current ERG)
Isolation: ERG 166: Isolate spill or leak area immediately for at least 25 to 50 meters in all directions. If fire or large spill, isolate 800 meters in all directions. Evacuate downwind due to toxic HF vapor formation.
Chemical & Response Details
| Also known as | Uranium hexafluorideUF6Uranium(VI) fluorideHexFissile uranium hexafluoride |
| CAS Number | 7783-81-5 |
| Appearance | Colorless to white crystalline solid at room temperature. Sublimes readily to form a colorless, highly reactive gas. Pungent, acrid odor due to formation of hydrogen fluoride in moist air. |
| Flash Point | Not applicable (non-flammable inorganic compound) |
| Boiling Point | 56.5C (133.7F) - sublimes directly from solid to gas at atmospheric pressure |
| Vapor Density | 13 (much heavier than air) |
| Water Reactivity | Reacts vigorously with water and moisture to form highly toxic and corrosive hydrogen fluoride (HF) and uranyl fluoride. Chemical hazard greatly exceeds radiation hazard. |
| Extinguishing | Do not use water or foam. Use dry chemical, soda ash, or dry sand to contain spills. Avoid moisture exposure. |
| PPE | ⚠️ Level A suit for breach or significant exposure. Full-face SCBA required. Chemical-resistant gloves and suit. Radiation monitoring equipment. HF-specific protective gear critical. |
| Isolation | ERG 166: Isolate spill or leak area immediately for at least 25 to 50 meters in all directions. If fire or large spill, isolate 800 meters in all directions. Evacuate downwind due to toxic HF vapor formation. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- Radiation presents minimal risk to transport workers, emergency response personnel and the public
- Low radiation hazard to people. Chemical hazard greatly exceeds radiation hazard.
- Substance reacts with water and water vapor in air to form toxic and corrosive hydrogen fluoride gas,
- Toxic; may be fatal if inhaled, ingested, or absorbed through skin.
- Direct contact with substance and gas may cause burns to skin, eyes, or respiratory tract.
- Runoff from control of cargo fire may cause low-level pollution.
- Substance does not burn.
- The material may react violently with fuels.
First actions (field-minded)
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Priorities for rescue, life-saving, first aid, fire control and other hazards are higher than the
- 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
- Isolate spill or leak area for at least 25 meters (75 feet) in all directions.
- See Table 1 - Initial Isolation and Protective Action Distances.
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UN 2977 — Radioactive material, uranium hexafluori HAZMAT RADIO NOTE — UN 2977
Product: Radioactive material, uranium hexafluoride, fissile
Class 7 / Radioactive / ERG 166
PPE: Level A suit for breach or significant exposure. Full-face SCBA required. Chemical-resistant gloves and suit. Radiation monitoring equipment. HF-specific protective gear critical.
ISOLATION: ERG 166: Isolate spill or leak area immediately for at least 25 to 50 meters in all directions. If fire or large spill, isolate 800 meters in all directions. Evacuate downwind due to toxic HF vapor formation.
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 2977 — Radioactive material, uranium hexafluoride, fissile
Class: 7 | Placard: Radioactive | ERG Guide: 166
Appearance: Colorless to white crystalline solid at room temperature. Sublimes readily to form a colorless, highly reactive gas. Pungent, acrid odor due to formation of hydrogen fluoride in moist air.
Water Reactivity: Reacts vigorously with water and moisture to form highly toxic and corrosive hydrogen fluoride (HF) and uranyl fluoride. Chemical hazard greatly exceeds radiation hazard.
Extinguishing: Do not use water or foam. Use dry chemical, soda ash, or dry sand to contain spills. Avoid moisture exposure.
PPE: Level A suit for breach or significant exposure. Full-face SCBA required. Chemical-resistant gloves and suit. Radiation monitoring equipment. HF-specific protective gear critical.
Isolation: ERG 166: Isolate spill or leak area immediately for at least 25 to 50 meters in all directions. If fire or large spill, isolate 800 meters in all directions. Evacuate downwind due to toxic HF vapor formation.
— Key Hazards —
• Radiation presents minimal risk to transport workers, emergency response personnel and the public
• Low radiation hazard to people. Chemical hazard greatly exceeds radiation hazard.
• Substance reacts with water and water vapor in air to form toxic and corrosive hydrogen fluoride gas,
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Priorities for rescue, life-saving, first aid, fire control and other hazards are higher than the
• 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/2977 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2977 Radioactive material, uranium hexafluoride, fissile Cls7 ERG166 | allfirefighter.com/hazmat/un/2977SMS / 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/2977
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FAQ
Radiation presents minimal risk to transport workers, emergency response personnel and the public Low radiation hazard to people. Chemical hazard greatly exceeds radiation hazard. Substance reacts with water and water vapor in air to form toxic and corrosive hydrogen fluoride gas, Toxic; may be fatal if inhaled, ingested, or absorbed through skin. Direct contact with substance and gas may cause burns to skin, eyes, or respiratory tract. Runoff from control of cargo fire may cause low-level pollution. Substance does not burn. The material may react violently with fuels.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Priorities for rescue, life-saving, first aid, fire control and other hazards are higher than the Radiation Authority must be notified of accident conditions. Radiation Authority is usually responsible for
Level A suit for breach or significant exposure. Full-face SCBA required. Chemical-resistant gloves and suit. Radiation monitoring equipment. HF-specific protective gear critical.
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 166 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.