☣️ UN 1029 • CLASS 2

Dichlorofluoromethane

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 1029
Class: 2
Placard type: Non-Flammable Gas
ERG: Guide 126 (check current ERG)
Isolation: ERG 126: isolate spill/leak area 25-50m in all directions; if tank/rail car involved in fire, isolate 800m in all directions
Chemical & Response Details
Also known asR-21HCFC-21Freon 21FluorodichloromethaneDichloromonofluoromethane
CAS Number75-43-4
AppearanceColorless gas or liquid (under pressure) with a faint, ether-like odor. Shipped as a liquefied compressed gas.
Flash PointNot applicable (gas)
Boiling Point9°C (48°F)
Vapor Density3.8 (heavier than air)
Water ReactivityNo significant reaction with water
ExtinguishingCO2, dry chemical, water spray for cooling containers; foam not typically required
PPE⚠️ Level B minimum; SCBA required in confined spaces or high concentrations; chemical-resistant gloves and clothing
IsolationERG 126: isolate spill/leak area 25-50m 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 1029 — Dichlorofluoromethane
HAZMAT RADIO NOTE — UN 1029 Product: Dichlorofluoromethane Class 2 / Non-Flammable Gas / ERG 126 PPE: Level B minimum; SCBA required in confined spaces or high concentrations; chemical-resistant gloves and clothing ISOLATION: ERG 126: isolate spill/leak area 25-50m 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 1029 — Dichlorofluoromethane Class: 2 | Placard: Non-Flammable Gas | ERG Guide: 126 Appearance: Colorless gas or liquid (under pressure) with a faint, ether-like odor. Shipped as a liquefied compressed gas. Water Reactivity: No significant reaction with water Extinguishing: CO2, dry chemical, water spray for cooling containers; foam not typically required PPE: Level B minimum; SCBA required in confined spaces or high concentrations; chemical-resistant gloves and clothing Isolation: ERG 126: isolate spill/leak area 25-50m 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/1029 | 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)
UN1029 Dichlorofluoromethane Cls2 ERG126 | ERG 126: isolate spill/leak area 25-50m in all directions; if tank/rail car invo | allfirefighter.com/hazmat/un/1029SMS / 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/1029
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; chemical-resistant gloves and clothing

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.