UN 2609 — Triallyl borate
Placard: Toxic. ERG Guide 156. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2609 is Triallyl borate, a toxic combustible borate ester assigned to ERG Guide 156. Hydrolysis and toxic runoff must be controlled.
Hazard overview: TOXIC combustible/flammable borate ester liquid; inhalation, ingestion or skin contact may cause injury. Vapors may form ignitable mixtures when heated and can collect in low or confined areas. Reacts or hydrolyzes with water to form boric acid and allyl alcohol-type flammable products.
Response guidance: For UN 2609, isolate the area, eliminate ignition sources where relevant and use SCBA with chemical protection. Control water contact, contain toxic/corrosive runoff and choose agents using SDS and ERG 156.
Firefighter training notes: Training for UN 2609 should emphasize water/moisture reaction, toxic/corrosive vapor control, SCBA use, foam/dry-agent choice, decontamination and runoff containment. Use ERG 156, SDS and local SOP.
Regulatory context: Triallyl borate 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: Triallyl borate should be stored in tightly closed compatible containers with moisture control, ventilation, secondary containment and separation from heat, ignition sources, oxidizers and incompatible materials.
UN 2609 Quick Details
Common Hazards of UN 2609
- TOXIC combustible/flammable borate ester liquid; inhalation, ingestion or skin contact may cause injury.
- Vapors may form ignitable mixtures when heated and can collect in low or confined areas.
- Reacts or hydrolyzes with water to form boric acid and allyl alcohol-type flammable products.
- Liquid and vapor may irritate eyes, skin and respiratory tract.
- Runoff may be toxic, acidic/borate-contaminated and flammable-contaminated.
- Fire may produce carbon monoxide and irritating boron-containing smoke.
- Containers may rupture or fail when heated.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a characteristic ester-like odor. Liquid at room temperature.
| Also known as | Triallyl borateBoric acid triallyl esterAllyl borateTri(2-propenyl) borate |
| CAS Number | 7397-46-8 |
| Appearance | Colorless to pale yellow liquid with a characteristic ester-like odor. Liquid at room temperature. |
| Flash Point | 43°C (109°F) |
| Boiling Point | 120-130°C (248-266°F) at reduced pressure |
| Vapor Density | 3.4 (heavier than air) |
| Water Reactivity | Reacts with water releasing flammable vapors and boric acid; avoid direct water contact |
Fireground Response Guidance — UN 2609
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 2609 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, gas, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Keep water or moisture contact controlled when it may increase reaction, fuming or gas generation.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 156, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2609 — Triallyl borateUse 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.