☣️ UN 3478 • CLASS 2
UN 3478 — Fuel cell cartridges contained in equipment, containing liquefied flammable gas
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 3478 applies to fuel cell cartridges contained in equipment when the cartridge contains liquefied flammable gas.
Hazard overview: Released gas can vaporize quickly, form explosive mixtures with air, travel to ignition sources, and flash back. Heated containers may rupture.
Response guidance: Isolate the area, remove ignition sources, ventilate from upwind, and use dry chemical or CO2. Use water spray only to cool exposed equipment.
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UN 3478 Quick Details
UN 3478
Product name: Fuel cell cartridges contained in equipment, containing liquefied flammable gas
DOT Class: 2
Placard type: Flammable Gas
ERG Guide: 115 (check current ERG)
Initial isolation: ERG 115: isolate spill/leak area immediately for at least 100m in all directions; if tank/rail car involved in fire, isolate 800m in all directions
Common Hazards of UN 3478
- 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
The liquefied flammable gas is contained within fuel cell cartridge assemblies integrated into equipment, which are typically made of metal or plastic.
| Also known as | Fuel cell cartridges in equipmentLiquefied flammable gas fuel cellsEquipment-contained fuel cell cartridgesLFG fuel cell cartridges |
| Appearance | Liquefied flammable gas contained within fuel cell cartridge assemblies integrated into equipment. The gas is stored under pressure in liquid form and vaporizes upon release. |
| Flash Point | Not applicable (liquefied gas under pressure) |
| Boiling Point | Varies by specific gas (typically below room temperature for liquefied flammable gases) |
| Vapor Density | Heavier than air (vapors will collect in low areas) |
| Water Reactivity | No significant reaction with water, but gas dispersion in water may occur |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3478
Extinguishing Media
Water spray, dry chemical, CO2; foam may be used to suppress vapors
PPE Requirements
⚠️ Level B minimum; SCBA required in confined spaces or heavy vapor concentrations; flame-resistant clothing recommended
Level B with SCBA is recommended in confined areas, fire, or heavy vapor conditions. Flame-resistant clothing and eye protection should be used.
Isolation & Evacuation
ERG 115: isolate spill/leak area immediately for at least 100m in all directions; if tank/rail car involved in fire, isolate 800m in all directions
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 115).
First Actions for a UN 3478 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 3478 — Fuel cell cartridges contained in equipmHAZMAT RADIO NOTE — UN 3478
Product: Fuel cell cartridges contained in equipment, containing liquefied flammable gas
Class 2 / Flammable Gas / ERG 115
PPE: Level B minimum; SCBA required in confined spaces or heavy vapor concentrations; flame-resistant clothing recommended
ISOLATION: ERG 115: isolate spill/leak area immediately for at least 100m in all directions; if tank/rail car involved in fire, isolate 800m in all directions
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 3478 — Fuel cell cartridges contained in equipment, containing liquefied flammable gas
Class: 2 | Placard: Flammable Gas | ERG Guide: 115
Appearance: Liquefied flammable gas contained within fuel cell cartridge assemblies integrated into equipment. The gas is stored under pressure in liquid form and vaporizes upon release.
Water Reactivity: No significant reaction with water, but gas dispersion in water may occur
Extinguishing: Water spray, dry chemical, CO2; foam may be used to suppress vapors
PPE: Level B minimum; SCBA required in confined spaces or heavy vapor concentrations; flame-resistant clothing recommended
Isolation: ERG 115: isolate spill/leak area immediately for at least 100m in all directions; if tank/rail car involved in fire, isolate 800m in all directions
— 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-3478 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN3478 Fuel cell cartridges contained in equipment, containing liquefied flammable gas Cls2 ERG115 | allfirefighter.com/hazmat/un/fuel-cell-cartridges-contained-un-3478SMS / 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-3478
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Frequently Asked Questions about UN 3478
Yes. It contains liquefied flammable gas that may ignite easily.
No significant reaction is expected, but water should mainly be used as spray for cooling, not to direct at a release.
Level B with SCBA and flame-resistant protection is recommended for vapor, fire, or confined-space response.
Isolate at least 100 m, remove ignition sources, and cool exposed equipment from a safe distance.
UN 3478 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.