☣️ UN 3339 • CLASS 2

Refrigerant gas R-407B

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 3339
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 distances for large spills or container fires
Chemical & Response Details
Also known asR-407BHFC-407BRefrigerant blend R-407BR407B refrigerantHFC blend 407B
AppearanceColorless, non-flammable liquefied gas with a faint ether-like odor. Stored under pressure as a liquid.
Flash PointNot applicable (non-flammable gas)
Boiling PointApproximately -47C (-53F) for the blend
Vapor Density3.8 (heavier than air)
Water ReactivityNo significant reaction with water
ExtinguishingCO2, dry chemical, water spray; foam not typically required for non-flammable gas
PPE⚠️ Level B minimum; SCBA required in confined spaces or high concentrations; insulated gloves for liquid contact to prevent frostbite
IsolationERG 126: isolate spill or leak area immediately for at least 100m in all directions; increase distances for large spills or container 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 3339 — Refrigerant gas R-407B
HAZMAT RADIO NOTE — UN 3339 Product: Refrigerant gas R-407B Class 2 / Non-Flammable Gas / ERG 126 PPE: Level B minimum; SCBA required in confined spaces or high concentrations; insulated gloves for liquid contact to prevent frostbite ISOLATION: ERG 126: isolate spill or leak area immediately for at least 100m in all directions; increase distances for large spills or container fires ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 3339 — Refrigerant gas R-407B Class: 2 | Placard: Non-Flammable Gas | ERG Guide: 126 Appearance: Colorless, non-flammable liquefied gas with a faint ether-like odor. Stored under pressure as a liquid. Water Reactivity: No significant reaction with water Extinguishing: CO2, dry chemical, water spray; foam not typically required for non-flammable gas PPE: Level B minimum; SCBA required in confined spaces or high concentrations; insulated gloves for liquid contact to prevent frostbite Isolation: ERG 126: isolate spill or leak area immediately for at least 100m in all directions; increase distances for large spills or container 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/3339 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.

SMS (short)
UN3339 Refrigerant gas R-407B Cls2 ERG126 | ERG 126: isolate spill or leak area immediately for at least 100m in all directi | allfirefighter.com/hazmat/un/3339SMS / 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/3339
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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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 high concentrations; insulated gloves for liquid contact to prevent frostbite

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.