UN 2656 — Quinoline
Placard: Toxic. ERG Guide 154. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2656 is Quinoline, a toxic combustible nitrogen heterocycle assigned to ERG Guide 154. Vapor and skin exposure must be controlled.
Hazard overview: TOXIC combustible nitrogen heterocycle liquid; inhalation, ingestion or skin absorption may cause injury. Combustible liquid; heated vapors may form ignitable mixtures with air. Vapors are heavier than air and may collect in low or confined areas.
Response guidance: For UN 2656, isolate the area, avoid skin contact and use SCBA where dust, vapor, mist or fire is present. Prevent spread of contaminated runoff, cool containers from protection and verify controls with SDS and ERG 154.
Firefighter training notes: Training for UN 2656 should emphasize toxic exposure routes, skin absorption, SCBA use, dust/vapor control, decontamination, runoff containment and SDS verification. Use ERG 154, SDS and local SOP.
Regulatory context: Quinoline is regulated as a hazardous material for transport and emergency response. Storage, exposure, spill reporting, waste and fire-code duties depend on quantity, concentration and jurisdiction; verify shipping papers, SDS and local authority requirements.
Storage & handling: Quinoline should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and separation from heat, oxidizers and incompatible materials.
UN 2656 Quick Details
Common Hazards of UN 2656
- TOXIC combustible nitrogen heterocycle liquid; inhalation, ingestion or skin absorption may cause injury.
- Combustible liquid; heated vapors may form ignitable mixtures with air.
- Vapors are heavier than air and may collect in low or confined areas.
- Liquid and vapor can irritate eyes, skin and respiratory tract.
- Fire may produce nitrogen oxides and irritating/toxic smoke.
- Runoff may carry toxic contamination.
- Skin contact and contaminated clothing can extend exposure.
Chemical Identity & Physical Properties
Colorless to pale yellow oily liquid with a strong, unpleasant odor. Darkens on exposure to light. Hygroscopic.
| Also known as | 1-AzanaphthaleneBenzazineBenzo[b]pyridineChinolineLeukoline |
| CAS Number | 91-22-5 |
| Appearance | Colorless to pale yellow oily liquid with a strong, unpleasant odor. Darkens on exposure to light. Hygroscopic. |
| Flash Point | 101°C (214°F) |
| Boiling Point | 237°C (459°F) |
| Vapor Density | 4.5 (heavier than air) |
| Water Reactivity | Slightly soluble in water; no significant violent reaction |
Fireground Response Guidance — UN 2656
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for dust, vapor, mist, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 2656 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind, uphill and upstream.
- Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated dust, liquid, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 154, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2656 — QuinolineUse 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.