UN 2541 — Terpinolene
Placard: Flammable. ERG Guide 128. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Terpinolene is a volatile, pine-scented flammable liquid shipped as UN 2541. The main emergency concern is vapor ignition, flashback and spread into drains or confined spaces.
Hazard overview: Terpinolene vapors are heavier than air and can form explosive mixtures. Vapor may travel to ignition sources and flash back, making drain, sewer and low-area control important.
Response guidance: Eliminate ignition sources, isolate the spill and keep responders upwind. Use foam, dry chemical or CO2 for fire; water spray may be used to cool exposed containers but may not control the liquid fire by itself.
Firefighter training notes: Train crews on flammable liquid vapor travel, flashback and drain protection. Practice foam application and container cooling from a protected position.
Regulatory context: UN 2541 is transported as Terpinolene, Class 3 flammable liquid. Confirm packing group, quantity and emergency contact details on shipping papers.
Storage & handling: Store in closed, grounded containers away from heat, sparks, oxidizers and direct sunlight. Keep in a cool, well-ventilated flammable liquid area.
UN 2541 Quick Details
Common Hazards of UN 2541
- Terpinolene is a flammable liquid; vapors can ignite from heat, sparks, static or open flame.
- Vapors may form explosive mixtures with air, especially in low or confined areas.
- Vapor can travel along the ground to an ignition source and flash back.
- Runoff to sewers, drains or basements can create a fire or explosion hazard.
- Containers may rupture or explode when heated.
- Burning liquid can produce irritating smoke and carbon oxides.
- Liquid contact may irritate skin and eyes.
Chemical Identity & Physical Properties
Terpinolene is a colorless to pale yellow liquid with a fresh pine or citrus-like odor. It is insoluble in water and floats as a flammable layer.
| Also known as | p-Mentha-1,4(8)-diene1-Methyl-4-isopropenyl-1-cyclohexeneTerpinolenDelta-terpinene |
| CAS Number | 586-62-9 |
| Appearance | Colorless to pale yellow liquid with a fresh, piney, citrus-like odor. Liquid at room temperature. |
| Flash Point | 50C (122F) |
| Boiling Point | 185-186C (365-367F) |
| Vapor Density | 4.7 (heavier than air) |
| Water Reactivity | Insoluble in water; no significant reaction |
Fireground Response Guidance — UN 2541
Extinguishing Media
PPE Requirements
Use SCBA for fire or high vapor areas. Wear chemical-resistant gloves, splash protection and protective clothing to prevent liquid contact.
Isolation & Evacuation
First Actions for a UN 2541 Incident
- Call 911 and the emergency response number on the shipping papers.
- Keep unauthorized personnel away and remove ignition sources if it can be done safely.
- Stay upwind, uphill and upstream; avoid low areas where vapor may collect.
- Avoid breathing vapor and prevent skin or eye contact.
- Do not touch damaged containers or walk through spilled liquid without PPE.
- Ventilate confined spaces only if trained, equipped and using atmospheric monitoring.
- Use ERG 128, SDS and shipping papers to confirm isolation, foam selection and cleanup.
📋 Copy & Share Field Card
UN 2541 — TerpinoleneUse 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.