UN 2518 — Cyclododecatriene
Placard: Toxic. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2518 is Cyclododecatriene, a toxic combustible diene assigned to ERG Guide 153. SDS review is important for isomer/inhibitor and polymerization concerns.
Hazard overview: TOXIC combustible diene liquid; inhalation, ingestion or skin contact may cause injury. Vapors may form ignitable mixtures when heated and can collect in low or confined areas. Liquid may be insoluble and spread contamination on surfaces or water.
Response guidance: For UN 2518, isolate the area, avoid skin contact and use SCBA where dust, vapor, mist or fire is present. Contain toxic/corrosive runoff and verify product controls with SDS and ERG 153.
Firefighter training notes: Training for UN 2518 should emphasize toxic/corrosive exposure routes, skin absorption, SCBA use, decontamination, runoff containment and SDS verification. Use ERG 153, SDS and local SOP.
Regulatory context: Cyclododecatriene 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: Cyclododecatriene should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 2518 Quick Details
Common Hazards of UN 2518
- TOXIC combustible diene liquid; inhalation, ingestion or skin contact may cause injury.
- Vapors may form ignitable mixtures when heated and can collect in low or confined areas.
- Liquid may be insoluble and spread contamination on surfaces or water.
- May polymerize or vary by isomer/inhibitor status; verify SDS and shipping papers.
- Fire may produce carbon monoxide and irritating/toxic smoke.
- Runoff may carry toxic hydrocarbon contamination.
- Containers may rupture or fail when heated.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a mild, characteristic odor. Liquid at room temperature.
| Also known as | CDTCyclododecatrienetrans,trans,trans-CyclododecatrieneCyclododecatriene |
| CAS Number | 4904-61-4 |
| Appearance | Colorless to pale yellow liquid with a mild, characteristic odor. Liquid at room temperature. |
| Flash Point | 46C (115F) |
| Boiling Point | 240C (464F) |
| Vapor Density | 5.6 (heavier than air) |
| Water Reactivity | No significant reaction with water; insoluble |
Fireground Response Guidance — UN 2518
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 2518 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 153, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2518 — CyclododecatrieneUse 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.