☣️ UN 3479 • CLASS 2
UN 3479 — Fuel cell cartridges contained in equipment, containing hydrogen in metal hydride
Placard: Flammable Gas. ERG Guide 115. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ Verification required:
Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ 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.
UN 3479 covers fuel cell cartridges contained in equipment that store hydrogen in metal hydride materials.
Hazard overview: Heat, damage, or water contact may release hydrogen gas. Hydrogen is extremely flammable and may accumulate in confined or poorly ventilated spaces.
Response guidance: Isolate the area, monitor for hydrogen, keep away from water if metal hydride is burning, and use dry chemical, CO2, or dry sand where appropriate.
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UN 3479 Quick Details
UN 3479
Product name: Fuel cell cartridges contained in equipment, containing hydrogen in metal hydride
DOT Class: 2
Placard type: Flammable Gas
ERG Guide: 115 (check current ERG)
Initial isolation: ERG 115: Initial isolation 100m all directions; if fire or spill is large, isolate 800m all directions; evacuate area and deny entry
Common Hazards of UN 3479
- EXTREMELY FLAMMABLE.
- Will be easily ignited by heat, sparks or flames.
- Will form explosive mixtures with air.
- Vapors from liquefied gas are initially heavier than air and spread along ground.
- Vapors may travel to source of ignition and flash back.
- Cylinders exposed to fire may vent and release flammable gas through pressure relief devices.
- Containers may explode when heated.
- Ruptured cylinders may rocket.
Chemical Identity & Physical Properties
Fuel cell cartridges are typically gray or metallic in color and housed in equipment, with hydrogen stored in the metal lattice structure.
| Also known as | Fuel cell cartridges with metal hydrideHydrogen metal hydride fuel cellsMetal hydride hydrogen storage cartridges |
| Appearance | Solid metal hydride cartridges containing absorbed hydrogen gas. Cartridges are typically gray or metallic in color and housed in equipment. Hydrogen is stored in the metal lattice structure and released when heated. |
| Flash Point | Not applicable (hydrogen gas is extremely flammable with autoignition temperature 500C/932F) |
| Boiling Point | Not applicable (hydrogen boiling point -253C/-423F, stored as metal hydride) |
| Vapor Density | Not applicable when stored; released hydrogen is 0.07 (much lighter than air) |
| Water Reactivity | Metal hydrides may react with water to release hydrogen gas, increasing fire hazard |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3479
Extinguishing Media
CO2, dry chemical, or dry sand for metal fires; regular foam ineffective; do not use water on burning metal hydride
PPE Requirements
⚠️ Level B minimum with SCBA; full face shield and thermal protection for fire; monitor for hydrogen accumulation in confined spaces
Level B with SCBA, face shield, and thermal protection is recommended for fire, venting, or confined-space incidents.
Isolation & Evacuation
ERG 115: Initial isolation 100m all directions; if fire or spill is large, isolate 800m all directions; evacuate area and deny entry
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 115).
First Actions for a UN 3479 Incident
- CALL 911. Then call the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Many gases are heavier than air and may spread along the ground and collect in low or confined areas.
- Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
- Consider initial downwind evacuation for at least 800 meters (1/2 mile).
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📋 Copy & Share Field Card
UN 3479 — Fuel cell cartridges contained in equipmHAZMAT RADIO NOTE — UN 3479
Product: Fuel cell cartridges contained in equipment, containing hydrogen in metal hydride
Class 2 / Flammable Gas / ERG 115
PPE: Level B minimum with SCBA; full face shield and thermal protection for fire; monitor for hydrogen accumulation in confined spaces
ISOLATION: ERG 115: Initial isolation 100m all directions; if fire or spill is large, isolate 800m all directions; evacuate area and deny entry
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 3479 — Fuel cell cartridges contained in equipment, containing hydrogen in metal hydride
Class: 2 | Placard: Flammable Gas | ERG Guide: 115
Appearance: Solid metal hydride cartridges containing absorbed hydrogen gas. Cartridges are typically gray or metallic in color and housed in equipment. Hydrogen is stored in the metal lattice structure and released when heated.
Water Reactivity: Metal hydrides may react with water to release hydrogen gas, increasing fire hazard
Extinguishing: CO2, dry chemical, or dry sand for metal fires; regular foam ineffective; do not use water on burning metal hydride
PPE: Level B minimum with SCBA; full face shield and thermal protection for fire; monitor for hydrogen accumulation in confined spaces
Isolation: ERG 115: Initial isolation 100m all directions; if fire or spill is large, isolate 800m all directions; evacuate area and deny entry
— Key Hazards —
• EXTREMELY FLAMMABLE.
• Will be easily ignited by heat, sparks or flames.
• Will form explosive mixtures with air.
— First Actions —
• CALL 911. Then call the emergency response number on the shipping paper, if available.
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Many gases are heavier than air and may spread along the ground and collect in low or confined areas.
SOURCE: allfirefighter.com/hazmat/un/fuel-cell-cartridges-contained-un-3479 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN3479 Fuel cell cartridges contained in equipment, containing hydrogen in metal hydride Cls2 ERG115 | allfirefighter.com/hazmat/un/fuel-cell-cartridges-contained-un-3479SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/fuel-cell-cartridges-contained-un-3479
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Frequently Asked Questions about UN 3479
Yes. Released hydrogen is extremely flammable.
Metal hydrides may react with water and release hydrogen gas, especially if damaged or burning.
Level B with SCBA, face shield, and thermal protection is recommended for fire or release response.
Isolate the area, ventilate from upwind, monitor for hydrogen, and avoid water on burning metal hydride.
UN 3479 is assigned to ERG Guide 115 for initial emergency response guidance.
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.