UN 1149 — Dibutyl ethers
Placard: Flammable. ERG Guide 128. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1149 is Dibutyl ethers, a Class 3 flammable ether liquid assigned to ERG Guide 128. It can generate vapors that ignite easily and may present peroxide concerns if old or improperly stored.
Hazard overview: UN 1149 presents flammable vapor, flashback and potential peroxide-related handling hazards. Vapors are heavier than air and can collect in low or sewer areas; old containers should not be disturbed until assessed through SDS and specialist guidance.
Response guidance: For a UN 1149 incident, responders should confirm the product using shipping papers, container markings, SDS and ERG Guide 128. Establish incident command, isolate the area, stay upwind and uphill, remove ignition sources when safe, keep vapors or runoff out of sewers and use compatible Class B fire-control agents from a protected position.
Firefighter training notes: Training for UN 1149 should emphasize flammable ether vapor behavior, flashback, low-area vapor accumulation and possible peroxide issues in old containers. Common errors include disturbing suspect containers and ignoring sewer vapor explosion risk.
Regulatory context: Dibutyl ethers is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by formulation, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Dibutyl ethers should be stored in tightly closed compatible containers in a cool, dry, well-ventilated flammable-liquid area, away from heat, ignition sources and oxidizers. Follow SDS guidance for peroxide-forming ether storage, shelf-life checks and inhibitor requirements where applicable.
UN 1149 Quick Details
Common Hazards of UN 1149
- HIGHLY FLAMMABLE ether liquid; vapors may ignite easily and form explosive mixtures with air.
- Vapors may travel to an ignition source and flash back.
- Vapors are heavier than air and may collect in low, confined or sewer areas.
- Some ethers can form peroxides during storage; verify age, stabilizer and SDS before handling suspect containers.
- Fire may produce irritating or toxic combustion products.
- Runoff to sewer may create fire or explosion hazards.
- Containers may rupture or explode when heated.
Chemical Identity & Physical Properties
Clear, colorless liquid with a mild, ethereal odor. Less dense than water and immiscible with water.
| Also known as | n-Dibutyl etherButyl ether1-ButoxybutaneButane, 1,1'-oxybis-n-Butyl ether |
| CAS Number | 142-96-1 |
| Appearance | Clear, colorless liquid with a mild, ethereal odor. Less dense than water and immiscible with water. |
| Flash Point | -7°C (19°F) |
| Boiling Point | 142°C (288°F) |
| Vapor Density | 4.5 (heavier than air) |
| Water Reactivity | No significant reaction; immiscible with water |
Fireground Response Guidance — UN 1149
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fire or confined-space exposure. Wear chemical-resistant gloves and splash protection selected from SDS, and treat old or suspect ether containers cautiously because of possible peroxide concerns.
Isolation & Evacuation
First Actions for a UN 1149 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.
- Eliminate ignition sources if it is safe to do so.
- Do not touch or walk through spilled liquid unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped and authorized by incident command.
- Isolate the spill or leak area for at least 50 meters (150 feet) in all directions.
- For large spills, fire involvement or strong vapor movement, expand isolation and consider downwind evacuation based on monitoring and incident command.
- Use ERG Guide 128, shipping papers, SDS and local SOP for protective actions and entry decisions.
📋 Copy & Share Field Card
UN 1149 — Dibutyl ethersUse 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.