UN 1971 — Natural gas, compressed
Placard: Flammable Gas. ERG Guide 115. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1971 is Natural gas, compressed, a hazardous material assigned to ERG Guide 115. Responders should verify the exact product with shipping papers, markings and SDS.
Hazard overview: UN 1971 presents hazards that depend on product identity, packaging and incident conditions.
Response guidance: For a UN 1971 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 115. Establish incident command, isolate the area, stay upwind, control ignition or downwind hazards, cool exposed containers from a protected distance when appropriate and base entry decisions on monitoring and local SOP.
Firefighter training notes: Training for UN 1971 should emphasize gas vapor travel, flashback, cylinder cooling, BLEVE/rocket hazards, source isolation, invisible or low-lying vapor behavior and ignition control. Use ERG 115, SDS and local SOP.
Regulatory context: Natural gas, compressed is regulated as a hazardous material for transportation and emergency response purposes. Requirements for storage, workplace exposure, emergency planning, spill reporting and waste handling 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: Natural gas, compressed cylinders or containers should be secured in a cool, ventilated gas storage area away from heat, flames, ignition sources, oxidizers where incompatible and physical damage. Follow SDS and local code for gas detection and emergency shutoff.
UN 1971 Quick Details
Common Hazards of UN 1971
- EXTREMELY FLAMMABLE compressed gas; may ignite easily by heat, sparks or flame.
- Can form explosive mixtures with air.
- Gas may travel to ignition sources and flash back.
- Cylinders exposed to fire may vent, rupture or rocket.
- Contact with rapidly expanding gas may cause cold burns or frostbite.
- Flame may be difficult to see depending on gas and conditions.
- Do not extinguish a leaking gas fire unless the gas flow can be stopped safely.
Chemical Identity & Physical Properties
Colorless, odorless gas (odorized with mercaptans for leak detection). Lighter than air, disperses rapidly when released.
| Also known as | Compressed natural gasCNGMethane gasPipeline gas |
| CAS Number | 8006-14-2 |
| Appearance | Colorless, odorless gas (odorized with mercaptans for leak detection). Lighter than air, disperses rapidly when released. |
| Flash Point | Not applicable (gas) |
| Boiling Point | -161C (-258F) |
| Vapor Density | 0.6 (lighter than air) |
| Water Reactivity | No significant reaction |
Fireground Response Guidance — UN 1971
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for leak, vapor, fire or confined-space exposure. Wear flame-resistant protection, eye/face protection and insulated gloves where liquefied or cryogenic gas contact is possible.
Isolation & Evacuation
First Actions for a UN 1971 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 gas, vapor, smoke or mist and avoid skin or eye contact.
- Eliminate ignition sources if safe and keep gas or vapor out of drains, sewers, basements and low areas.
- 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 release area and expand the perimeter for fire involvement, cylinder heating, vapor accumulation, unknown gas identity or downwind exposure.
- Use ERG Guide 115, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1971 — Natural gas, 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.