UN 2690 — N,n-Butylimidazole
Placard: Toxic. ERG Guide 152. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
N,n-Butylimidazole is a toxic organic base liquid. Skin absorption and inhalation are key exposure routes during spills or fire.
Hazard overview: N,n-Butylimidazole is a toxic material requiring control of inhalation, ingestion and skin exposure. Fire or heating can increase toxic vapor, dust or smoke hazards.
Response guidance: Isolate the release, keep personnel upwind and prevent contact with liquid, solid or runoff. Use Alcohol-resistant foam, CO2, dry chemical, water spray as appropriate for fire, while protecting waterways.
Firefighter training notes: Train crews to identify N,n-Butylimidazole by UN number, placard, ERG guide and SDS before choosing entry, isolation or extinguishment tactics.
Regulatory context: Use UN 2690, ERG 152, SDS, container labels and shipping papers to confirm the exact hazard profile and protective action distances.
Storage & handling: Store in closed, compatible containers away from heat, ignition sources and incompatible materials; keep the area ventilated and protected from damage.
UN 2690 Quick Details
Common Hazards of UN 2690
- Toxic exposure by inhalation, ingestion or skin contact may cause serious injury.
- Contact can irritate or burn skin and eyes; avoid all unnecessary contact.
- Fire may generate irritating, corrosive or toxic gases.
- Combustible material may burn, although it may not ignite readily.
- Contaminated runoff may be toxic or corrosive and should be contained.
- Vapors, dust or aerosols can be more hazardous in confined or poorly ventilated areas.
- Heated containers may rupture or release hazardous vapors.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a characteristic amine-like odor at room temperature.
| Also known as | N-Butylimidazole1-Butylimidazole1-n-Butyl-1H-imidazoleButylimidazole |
| CAS Number | 4316-42-1 |
| Appearance | Colorless to pale yellow liquid with a characteristic amine-like odor at room temperature. |
| Flash Point | 79°C (174°F) |
| Boiling Point | 198°C (388°F) |
| Vapor Density | 4.3 (heavier than air) |
| Water Reactivity | Soluble in water; may form alkaline solutions |
Fireground Response Guidance — UN 2690
Extinguishing Media
PPE Requirements
Use SCBA with chemical-resistant gloves, boots and protective clothing; upgrade to full chemical protection when contact or vapor levels are uncertain.
Isolation & Evacuation
First Actions for a UN 2690 Incident
- Call 911 and the emergency response number shown on shipping papers or container documents.
- Keep unauthorized personnel away and establish an initial isolation perimeter.
- Stay upwind, uphill and upstream; avoid low areas where vapors or runoff may collect.
- Avoid breathing vapors, dust, smoke or mist and prevent skin and eye contact.
- Do not touch damaged containers or spilled material without appropriate chemical PPE.
- Ventilate confined spaces only when personnel are trained, monitored and properly equipped.
- Use ERG guidance, SDS, shipping papers and air monitoring before committing crews.
📋 Copy & Share Field Card
UN 2690 — N,n-ButylimidazoleUse 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.