☣️ UN 3340 • CLASS 2

Refrigerant gas R-407C

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 3340
Class: 2
Placard type: Non-Flammable Gas
ERG: Guide 126 (check current ERG)
Isolation: ERG 126: isolate spill/leak area 100m in all directions; if tank/rail car involved in fire, isolate 800m in all directions
Chemical & Response Details
Also known asR-407CHFC-407CDifluoromethane/Pentafluoroethane/Tetrafluoroethane blendR-32/R-125/R-134a mixture
CAS Number75-68-3
AppearanceColorless, liquefied gas with slight ethereal odor. Shipped as a pressurized liquid blend of three hydrofluorocarbons. Heavier than air.
Flash PointNot applicable (non-flammable gas)
Boiling Point-43.6C (-46.5F)
Vapor Density3.0 (heavier than air)
Water ReactivityNo significant reaction with water
ExtinguishingNot applicable (non-flammable); water spray may be used for cooling containers
PPE⚠️ Level B minimum; SCBA required in high concentrations due to asphyxiation hazard; insulated gloves for liquid contact
IsolationERG 126: isolate spill/leak area 100m in all directions; if tank/rail car involved in fire, isolate 800m in all directions
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 3340 — Refrigerant gas R-407C
HAZMAT RADIO NOTE — UN 3340 Product: Refrigerant gas R-407C Class 2 / Non-Flammable Gas / ERG 126 PPE: Level B minimum; SCBA required in high concentrations due to asphyxiation hazard; insulated gloves for liquid contact ISOLATION: ERG 126: isolate spill/leak area 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.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 3340 — Refrigerant gas R-407C Class: 2 | Placard: Non-Flammable Gas | ERG Guide: 126 Appearance: Colorless, liquefied gas with slight ethereal odor. Shipped as a pressurized liquid blend of three hydrofluorocarbons. Heavier than air. Water Reactivity: No significant reaction with water Extinguishing: Not applicable (non-flammable); water spray may be used for cooling containers PPE: Level B minimum; SCBA required in high concentrations due to asphyxiation hazard; insulated gloves for liquid contact Isolation: ERG 126: isolate spill/leak area 100m in all directions; if tank/rail car involved in fire, isolate 800m in all directions — 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/3340 | 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)
UN3340 Refrigerant gas R-407C Cls2 ERG126 | ERG 126: isolate spill/leak area 100m in all directions; if tank/rail car involv | allfirefighter.com/hazmat/un/3340SMS / 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/3340
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 high concentrations due to asphyxiation hazard; insulated gloves for liquid contact

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.