UN 2187 — Carbon dioxide, refrigerated liquid
Placard: Non-Flammable Gas. ERG Guide 120. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2187 is Carbon dioxide, refrigerated liquid, a non-flammable refrigerated gas assigned to ERG Guide 120. It can displace oxygen and cause cryogenic frostbite.
Hazard overview: NON-FLAMMABLE refrigerated carbon dioxide; vapor may displace oxygen and cause asphyxiation without warning. Cold vapor and liquid can cause severe frostbite and cryogenic burns. Heavy gas may collect in low or confined areas.
Response guidance: For a UN 2187 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 120. Establish incident command, isolate the area, stay upwind, control ignition or incompatibility hazards, prevent runoff or vapor spread and base entry/fire-control actions on monitoring and local SOP.
Firefighter training notes: Training for UN 2187 should emphasize exposure routes, air monitoring, PPE selection, fire behavior, decontamination, runoff containment and ERG/SDS verification. Use ERG 120, SDS and local SOP.
Regulatory context: Carbon dioxide, refrigerated liquid is regulated as a hazardous material for transportation and emergency response purposes. Storage, workplace exposure, emergency planning, spill reporting, waste handling and environmental requirements vary by exact product, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, container markings and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Carbon dioxide, refrigerated liquid containers should be secured in a cool, ventilated gas storage area away from heat, physical damage and incompatible materials. Toxic, corrosive, oxidizing or refrigerated gases require leak detection/ventilation and emergency planning as specified by SDS and local code.
UN 2187 Quick Details
Common Hazards of UN 2187
- NON-FLAMMABLE refrigerated carbon dioxide; vapor may displace oxygen and cause asphyxiation without warning.
- Cold vapor and liquid can cause severe frostbite and cryogenic burns.
- Heavy gas may collect in low or confined areas.
- Rapid vaporization can create pressure buildup and dense cold clouds.
- Containers may rupture or rocket when heated or over-pressurized.
- Gas is colorless and odorless, so oxygen deficiency may not be noticed.
- Ventilation and oxygen monitoring are critical in enclosed areas.
Chemical Identity & Physical Properties
Colorless, odorless cryogenic liquid. Boils at -78.5°C (-109.3°F) at atmospheric pressure, forming dense white vapor clouds.
| Also known as | Liquid carbon dioxideCO2 refrigerated liquidCryogenic carbon dioxideLiquefied CO2 |
| CAS Number | 124-38-9 |
| Appearance | Colorless, odorless cryogenic liquid. Boils at -78.5°C (-109.3°F) at atmospheric pressure, forming dense white vapor clouds. |
| Flash Point | Not applicable (non-flammable gas) |
| Boiling Point | -78.5C (-109.3F) at 1 atm |
| Vapor Density | 1.5 (heavier than air) |
| Water Reactivity | No significant reaction; will sublime to gas |
Fireground Response Guidance — UN 2187
Extinguishing Media
PPE Requirements
Use SCBA and oxygen monitoring in confined or oxygen-deficient areas. Wear face shield, insulated/cryogenic gloves and protective clothing where refrigerated liquid or cold vapor contact is possible.
Isolation & Evacuation
First Actions for a UN 2187 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, gas, dust, mist, smoke or fumes and avoid skin or eye contact.
- Avoid low or confined areas until oxygen readings are verified; protect against cryogenic frostbite.
- Do not touch damaged containers or spilled/released material unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or release area and expand the perimeter for fire involvement, vapor spread, gas accumulation, cylinder heating or unknown product identity.
- Use ERG Guide 120, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 2187 — Carbon dioxide, refrigerated liquidUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.