☣️ UN 2034 • CLASS 2
UN 2034 — Hydrogen and methane mixture, compressed
Placard: Flammable Gas. ERG Guide 115. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ 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 2034 Quick Details
UN 2034
Product name: Hydrogen and methane mixture, compressed
DOT Class: 2
Placard type: Flammable Gas
ERG Guide: 115 (check current ERG)
Initial isolation: ERG 115: isolate 100m all directions initially; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m
Common Hazards of UN 2034
- 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
| Also known as | Hydrogen-methane mixtureCompressed hydrogen-methane gasH2-CH4 mixtureMethane-hydrogen blend |
| Appearance | Colorless, odorless compressed gas mixture stored in high-pressure cylinders. Lighter than air and will rise and disperse rapidly when released. |
| Flash Point | Not applicable (compressed gas mixture) |
| Boiling Point | Not applicable (gas mixture: hydrogen -253C, methane -161C) |
| Vapor Density | 0.3-0.6 (lighter than air, depending on mixture ratio) |
| Water Reactivity | No reaction with water; gas will bubble through and disperse |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 2034
Extinguishing Media
Do not use water or foam; use dry chemical or CO2 for small fires, allow large fires to burn
PPE Requirements
⚠️ Level B minimum with SCBA; fire-resistant clothing for fire situations; avoid static-generating materials
Isolation & Evacuation
ERG 115: isolate 100m all directions initially; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 115).
First Actions for a UN 2034 Incident
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Many gases are heavier than air and will 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 2034 — Hydrogen and methane mixture, compressedHAZMAT RADIO NOTE — UN 2034
Product: Hydrogen and methane mixture, compressed
Class 2 / Flammable Gas / ERG 115
PPE: Level B minimum with SCBA; fire-resistant clothing for fire situations; avoid static-generating materials
ISOLATION: ERG 115: isolate 100m all directions initially; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m
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 2034 — Hydrogen and methane mixture, compressed
Class: 2 | Placard: Flammable Gas | ERG Guide: 115
Appearance: Colorless, odorless compressed gas mixture stored in high-pressure cylinders. Lighter than air and will rise and disperse rapidly when released.
Water Reactivity: No reaction with water; gas will bubble through and disperse
Extinguishing: Do not use water or foam; use dry chemical or CO2 for small fires, allow large fires to burn
PPE: Level B minimum with SCBA; fire-resistant clothing for fire situations; avoid static-generating materials
Isolation: ERG 115: isolate 100m all directions initially; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m
— 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 emergency response telephone number on shipping paper. If shipping paper
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Many gases are heavier than air and will spread along the ground and collect in low or confined areas
SOURCE: allfirefighter.com/hazmat/un/2034 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2034 Hydrogen and methane mixture, compressed Cls2 ERG115 | allfirefighter.com/hazmat/un/2034SMS / 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/2034
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Frequently Asked Questions about UN 2034
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.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.
Level B minimum with SCBA; fire-resistant clothing for fire situations; avoid static-generating materials
Water reactivity: No reaction with water; gas will bubble through and disperse. Recommended extinguishing: Do not use water or foam; use dry chemical or CO2 for small fires, allow large fires to burn.
ERG Guide 115 recommendation: ERG 115: isolate 100m all directions initially; if tank/rail car involved in fire, isolate 800m and consider evacuation 1600m
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 115 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.