UN 1003 — Air, refrigerated liquid (cryogenic liquid)
Placard: Non-Flammable Gas. ERG Guide 122. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1003 is Air, refrigerated liquid (cryogenic liquid), a Class 1 explosive entry assigned to ERG Guide 122. This entry requires isolation, evacuation and qualified explosive specialist support as primary responder priorities.
Hazard overview: UN 1003 presents a serious explosive hazard when exposed to fire, impact, shock, friction or other initiating conditions. Depending on division and quantity, detonation or projection may create severe blast, fragmentation and secondary debris hazards.
Response guidance: For a UN 1003 incident, responders should confirm the material using shipping papers, placards, package markings, SDS where applicable and ERG Guide 122. Establish incident command, isolate the area, deny entry, request law enforcement and EOD support, and withdraw personnel if fire involves the explosive material or containers.
Firefighter training notes: Training should emphasize recognizing Class 1 explosive placards, establishing command early, using standoff distance, denying entry and requesting bomb squad or EOD support. Common tactical errors include approaching packages for identification, moving damaged items, fighting fire too close and underestimating fragmentation distance. Use ERG 122, shipping papers and local explosive incident SOP.
Regulatory context: Air, refrigerated liquid (cryogenic liquid) is regulated as a Class 1 explosive hazardous material. Transportation, storage, quantity limits, fire code controls and reporting requirements may vary by jurisdiction. Responders should verify current requirements through shipping papers, SDS or product documents and applicable DOT, ATF, OSHA, NFPA, military, state or local authority guidance.
Storage & handling: Air, refrigerated liquid (cryogenic liquid) should be stored only in approved packaging, magazines or authorized explosive storage areas, separated from ignition sources, incompatible materials and unauthorized access. Packages should be protected from heat, impact, friction, moisture where relevant and physical damage according to product documentation and applicable explosive storage regulations.
UN 1003 Quick Details
Common Hazards of UN 1003
- Substance does not burn but will support combustion.
- Some may react explosively with fuels.
- May ignite combustibles (wood, paper, oil, clothing, etc.).
- Vapors from liquefied gas are initially heavier than air and spread along ground.
- Runoff may create fire or explosion hazard.
- Containers may explode when heated.
- Ruptured cylinders may rocket.
- Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas.
Chemical Identity & Physical Properties
Colorless to pale blue liquid with no odor. Extremely cold cryogenic liquid at approximately -190°C (-310°F). Boils rapidly at ambient temperature producing large volumes of gas.
| Also known as | Liquid airLOX/LIN mixtureCryogenic airLiquefied air |
| Appearance | Colorless to pale blue liquid with no odor. Extremely cold cryogenic liquid at approximately -190°C (-310°F). Boils rapidly at ambient temperature producing large volumes of gas. |
| Flash Point | Not applicable (non-flammable cryogenic gas) |
| Boiling Point | -194.4°C (-318°F) approximately |
| Vapor Density | 1.0 (equivalent to air when vaporized) |
| Water Reactivity | No chemical reaction, but extreme cold causes rapid freezing of water and potential brittle fracture of materials |
Fireground Response Guidance — UN 1003
Extinguishing Media
PPE Requirements
For UN 1003, distance, cover and evacuation are more important than close-range PPE. Structural firefighting gear and SCBA may be used only for remote exposure protection or support roles; direct approach or handling should be limited to qualified EOD or explosive specialists under incident command.
Isolation & Evacuation
First Actions for a UN 1003 Incident
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- 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).
📋 Copy & Share Field Card
UN 1003 — Air, refrigerated liquid (cryogenic liquUse 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.