UN 1127 — n-Butyl chloride
Placard: Flammable. ERG Guide 130. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
n-Butyl chloride is a highly flammable and volatile liquid that can form explosive mixtures with air, posing a significant risk of fire and explosion. It is commonly used as a solvent and intermediate in various chemical reactions.
Hazard overview: The substance is highly flammable and can be easily ignited by heat, sparks, or flames, causing a rapid spread of fire. Prolonged exposure to its vapors can also cause respiratory problems and other health issues.
Response guidance: In case of a spill or leak, evacuate the area immediately and call for emergency services. Firefighters should use alcohol-resistant foam, CO2, or dry chemical to extinguish the fire, while wearing Level B PPE with SCBA.
UN 1127 Quick Details
Common Hazards of UN 1127
- HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
- Vapors may form explosive mixtures with air.
- Vapors may travel to source of ignition and flash back.
- Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas
- Vapor explosion hazard indoors, outdoors or in sewers.
- Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
- Runoff to sewer may create fire or explosion hazard.
- Containers may explode when heated.
Chemical Identity & Physical Properties
n-Butyl chloride is a colorless liquid with a sharp, chloroform-like odor, which is volatile and highly flammable at room temperature.
| Also known as | 1-ChlorobutaneButyl chloriden-Butyl chloride1-Butyl chlorideChlorobutane |
| CAS Number | 109-69-3 |
| Appearance | Colorless liquid with a sharp, chloroform-like odor. Volatile and highly flammable at room temperature. |
| Flash Point | -12°C (10°F) |
| Boiling Point | 78°C (172°F) |
| Vapor Density | 3.2 (heavier than air) |
| Water Reactivity | Insoluble in water; no significant reaction. May float and spread on water surface. |
Fireground Response Guidance — UN 1127
Extinguishing Media
PPE Requirements
Responders should wear Level B PPE with SCBA, and a full chemical-resistant suit if there is a large spill or confined space to prevent skin contact and inhalation of vapors.
Isolation & Evacuation
First Actions for a UN 1127 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 50 meters (150 feet) in all directions.
- Consider initial downwind evacuation for at least 300 meters (1000 feet).
📋 Copy & Share Field Card
UN 1127 — n-Butyl chlorideUse 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.