☣️ UN 1973 • CLASS 2
UN 1973 — Chlorodifluoromethane and chloropentafluoroethane mixture
Placard: Non-Flammable Gas. ERG Guide 126. 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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UN 1973 Quick Details
UN 1973
Product name: Chlorodifluoromethane and chloropentafluoroethane mixture
DOT Class: 2
Placard type: Non-Flammable Gas
ERG Guide: 126 (check current ERG)
Initial isolation: ERG 126: Initial isolation 100m in all directions; for large spill isolate 800m downwind during day
Common Hazards of UN 1973
- 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.
Chemical Identity & Physical Properties
| Also known as | R-502Refrigerant 502HCFC-22/CFC-115 mixtureAzeotropic refrigerant blendGenetron 502 |
| Appearance | Colorless liquefied compressed gas with faint ethereal odor. Heavier than air as vapor. Stored under pressure in cylinders. |
| Flash Point | Not applicable (non-flammable gas) |
| Boiling Point | -45°C (-49°F) at atmospheric pressure |
| Vapor Density | 3.5 (air = 1) - heavier than air, vapors collect in low areas |
| Water Reactivity | No significant reaction with water. Slightly soluble in water. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1973
Extinguishing Media
Firefighting agents generally not needed (non-flammable); CO2 or dry chemical for adjacent fires
PPE Requirements
⚠️ Level B minimum for vapor release; SCBA required in confined spaces or high concentrations; chemical-resistant gloves; avoid skin contact with liquid (frostbite hazard)
Isolation & Evacuation
ERG 126: Initial isolation 100m in all directions; for large spill isolate 800m downwind during day
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 126).
First Actions for a UN 1973 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
- 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 1973 — Chlorodifluoromethane and chloropentafluHAZMAT RADIO NOTE — UN 1973
Product: Chlorodifluoromethane and chloropentafluoroethane mixture
Class 2 / Non-Flammable Gas / ERG 126
PPE: Level B minimum for vapor release; SCBA required in confined spaces or high concentrations; chemical-resistant gloves; avoid skin contact with liquid (frostbite hazard)
ISOLATION: ERG 126: Initial isolation 100m in all directions; for large spill isolate 800m downwind during day
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 1973 — Chlorodifluoromethane and chloropentafluoroethane mixture
Class: 2 | Placard: Non-Flammable Gas | ERG Guide: 126
Appearance: Colorless liquefied compressed gas with faint ethereal odor. Heavier than air as vapor. Stored under pressure in cylinders.
Water Reactivity: No significant reaction with water. Slightly soluble in water.
Extinguishing: Firefighting agents generally not needed (non-flammable); CO2 or dry chemical for adjacent fires
PPE: Level B minimum for vapor release; SCBA required in confined spaces or high concentrations; chemical-resistant gloves; avoid skin contact with liquid (frostbite hazard)
Isolation: ERG 126: Initial isolation 100m in all directions; for large spill isolate 800m downwind during day
— 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/1973 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1973 Chlorodifluoromethane and chloropentafluoroethane mixture Cls2 ERG126 | allfirefighter.com/hazmat/un/1973SMS / 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/1973
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Frequently Asked Questions about UN 1973
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 for vapor release; SCBA required in confined spaces or high concentrations; chemical-resistant gloves; avoid skin contact with liquid (frostbite hazard)
Water reactivity: No significant reaction with water. Slightly soluble in water.. Recommended extinguishing: Firefighting agents generally not needed (non-flammable); CO2 or dry chemical for adjacent fires.
ERG Guide 126 recommendation: ERG 126: Initial isolation 100m in all directions; for large spill isolate 800m downwind during day
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.