UN 1002 — Air, compressed
Placard: Non-Flammable Gas. ERG Guide 122. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Compressed air is a non-flammable gas that is commonly used in a variety of applications. While it does not burn, it can support combustion and can be involved in fires.
Hazard overview: Compressed air can support combustion, and can be involved in fires, particularly if it is mixed with a fuel source. It can also displace oxygen, which can lead to asphyxiation in confined spaces.
Response guidance: In the event of an emergency, responders should isolate the area and use water spray to cool cylinders if they are involved in a fire. Compressed air does not require extinguishing, but surrounding fires can be extinguished using CO2, dry chemical, or water spray.
UN 1002 Quick Details
Common Hazards of UN 1002
- 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
Compressed air is a colorless, odorless gas that is compressed in cylinders, and consists primarily of nitrogen and oxygen at ambient temperature.
| Also known as | Compressed airAirAtmospheric air compressed |
| CAS Number | 132259-10-0 |
| Appearance | Colorless, odorless gas compressed in cylinders. Consists primarily of nitrogen (78%) and oxygen (21%) at ambient temperature. |
| Flash Point | Not applicable (non-flammable gas) |
| Boiling Point | Not applicable (mixture of gases) |
| Vapor Density | 1.0 (same as air) |
| Water Reactivity | No reaction with water |
Fireground Response Guidance — UN 1002
Extinguishing Media
PPE Requirements
Responders should wear Level D protective equipment for normal operations, and SCBA and protective clothing if cylinders are involved in a fire or leak in a confined space.
Isolation & Evacuation
First Actions for a UN 1002 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 1002 — Air, compressedUse 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.