☣️ UN 3337 • CLASS 2
Refrigerant gas R-404A
Placard: Non-Flammable Gas. 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 3337
Class: 2
Placard type: Non-Flammable Gas
ERG: Guide 126 (check current ERG)
Isolation: ERG 126: isolate spill or leak area immediately for at least 100m in all directions; increase isolation distance for large spills or cylinder fires
Chemical & Response Details
| Also known as | R-404AHFC-404ASuva 404AGenetron 404AForane 404A |
| Appearance | Colorless, liquefied gas with slight ether-like odor. Exists as a liquid under pressure at room temperature; vaporizes rapidly when released to atmosphere. |
| Flash Point | Not applicable (non-flammable gas) |
| Boiling Point | -46C (-51F) |
| Vapor Density | 3.8 (heavier than air) |
| Water Reactivity | No significant reaction with water |
| Extinguishing | Dry chemical, CO2; foam not typically required for non-flammable gas |
| PPE | ⚠️ Level B minimum; SCBA required in confined spaces or large releases due to asphyxiation hazard; thermal gloves for liquid contact (frostbite risk) |
| Isolation | ERG 126: isolate spill or leak area immediately for at least 100m in all directions; increase isolation distance for large spills or cylinder fires |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- Some may burn but none ignite readily.
- Containers may explode when heated.
- Ruptured cylinders may rocket.
- Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas.
- Vapors from liquefied gas are initially heavier than air and spread along ground.
- Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
- Fire may produce irritating, corrosive and/or toxic gases.
First actions (field-minded)
- 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
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
- Consider initial downwind evacuation for at least 500 meters (1/3 mile).
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UN 3337 — Refrigerant gas R-404A HAZMAT RADIO NOTE — UN 3337
Product: Refrigerant gas R-404A
Class 2 / Non-Flammable Gas / ERG 126
PPE: Level B minimum; SCBA required in confined spaces or large releases due to asphyxiation hazard; thermal gloves for liquid contact (frostbite risk)
ISOLATION: ERG 126: isolate spill or leak area immediately for at least 100m in all directions; increase isolation distance for large spills or cylinder fires
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 3337 — Refrigerant gas R-404A
Class: 2 | Placard: Non-Flammable Gas | ERG Guide: 126
Appearance: Colorless, liquefied gas with slight ether-like odor. Exists as a liquid under pressure at room temperature; vaporizes rapidly when released to atmosphere.
Water Reactivity: No significant reaction with water
Extinguishing: Dry chemical, CO2; foam not typically required for non-flammable gas
PPE: Level B minimum; SCBA required in confined spaces or large releases due to asphyxiation hazard; thermal gloves for liquid contact (frostbite risk)
Isolation: ERG 126: isolate spill or leak area immediately for at least 100m in all directions; increase isolation distance for large spills or cylinder fires
— Key Hazards —
• Some may burn but none ignite readily.
• Containers may explode when heated.
• Ruptured cylinders may rocket.
— 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/3337 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3337 Refrigerant gas R-404A Cls2 ERG126 | ERG 126: isolate spill or leak area immediately for at least 100m in all directi | allfirefighter.com/hazmat/un/3337SMS / 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/3337
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FAQ
Some may burn but none ignite readily. Containers may explode when heated. Ruptured cylinders may rocket. Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas. Vapors from liquefied gas are initially heavier than air and spread along ground. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating, corrosive and/or toxic gases.
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; SCBA required in confined spaces or large releases due to asphyxiation hazard; thermal gloves for liquid contact (frostbite risk)
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 126 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.