UN 2616 — Triisopropyl borate
Placard: Flammable. ERG Guide 129. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2616 is Triisopropyl borate, a flammable borate ester assigned to ERG Guide 129. Hydrolysis can form alcohol and borate contamination.
Hazard overview: FLAMMABLE borate ester liquid; vapors may ignite and form explosive mixtures with air. Hydrolyzes slowly with water to form boric acid and isopropanol, which may add flammable vapor hazard. Vapors are heavier than air and may travel to ignition sources and flash back.
Response guidance: For UN 2616, isolate the area, eliminate ignition sources when flammable vapors are present and use SCBA. Keep vapors out of drains, cool containers from protection and select foam/dry chemical/CO2 from SDS and ERG 129.
Firefighter training notes: Training for UN 2616 should emphasize vapor travel, sewer flashback, foam selection, ignition control, SCBA use, decontamination, container cooling and runoff containment. Use ERG 129, SDS and local SOP.
Regulatory context: Triisopropyl 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: Triisopropyl 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 2616 Quick Details
Common Hazards of UN 2616
- FLAMMABLE borate ester liquid; vapors may ignite and form explosive mixtures with air.
- Hydrolyzes slowly with water to form boric acid and isopropanol, which may add flammable vapor hazard.
- Vapors are heavier than air and may travel to ignition sources and flash back.
- Vapor explosion hazard exists in drains, sewers, basements and confined areas.
- Runoff may carry flammable alcohol/borate contamination.
- Fire may produce carbon monoxide and irritating boron-containing smoke.
- Containers may rupture or explode when heated.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a mild, fruity or alcohol-like odor. Liquid at room temperature.
| Also known as | Boric acid triisopropyl esterTriisopropoxyborateIsopropyl borateTri-n-propyl borate |
| CAS Number | 5419-55-6 |
| Appearance | Colorless to pale yellow liquid with a mild, fruity or alcohol-like odor. Liquid at room temperature. |
| Flash Point | 38°C (100°F) |
| Boiling Point | 139-142°C (282-288°F) |
| Vapor Density | 4.8 (heavier than air) |
| Water Reactivity | Hydrolyzes slowly in water to form boric acid and isopropanol; no violent reaction but can release flammable alcohol vapors |
Fireground Response Guidance — UN 2616
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, smoke, fire or confined-space exposure. Wear chemical-resistant gloves, eye/face protection and flame-resistant protection as appropriate.
Isolation & Evacuation
First Actions for a UN 2616 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.
- Eliminate ignition sources if this can be done safely.
- 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.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 129, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2616 — Triisopropyl 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.