UN 2965 — Boron trifluoride dimethyl etherate
Placard: Dangerous When Wet. ERG Guide 139. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2965 is Boron trifluoride dimethyl etherate, a dangerous-when-wet flammable BF3 etherate assigned to ERG Guide 139. Moisture can release HF-containing fumes.
Hazard overview: DANGEROUS WHEN WET and flammable boron trifluoride etherate liquid; water can release toxic hydrogen fluoride. Moisture contact may generate heat, corrosive HF-containing fumes and flammable ether vapors. Vapors are heavier than air and may travel to ignition sources and flash back.
Response guidance: For UN 2965, isolate the area, control moisture contact and use SCBA with chemical protection. Contain HF/toxic runoff and request specialist support under ERG 139.
Firefighter training notes: Training for UN 2965 should emphasize exposure routes, SCBA use, vapor/dust monitoring, decontamination, runoff containment and SDS verification. Use ERG 139, SDS and local SOP.
Regulatory context: Boron trifluoride dimethyl etherate is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Boron trifluoride dimethyl etherate should be stored dry in tightly closed compatible containers away from moisture, heat, ignition sources and incompatible materials. Keep compatible dry media available.
UN 2965 Quick Details
Common Hazards of UN 2965
- DANGEROUS WHEN WET and flammable boron trifluoride etherate liquid; water can release toxic hydrogen fluoride.
- Moisture contact may generate heat, corrosive HF-containing fumes and flammable ether vapors.
- Vapors are heavier than air and may travel to ignition sources and flash back.
- Liquid and vapor can severely burn eyes, skin and respiratory tissue.
- Fire may produce hydrogen fluoride, boron oxides and irritating/toxic smoke.
- Runoff may be acidic, fluoride-contaminated, corrosive and toxic.
- Containers may rupture when heated or contaminated with water.
Chemical Identity & Physical Properties
Clear to pale yellow liquid with a pungent, irritating odor. Fuming liquid that reacts with moisture in air.
| Also known as | Boron trifluoride dimethyl etherateBF3 dimethyl etherateBoron trifluoride-dimethyl ether complexBF3-DMEDimethyl etherate of boron trifluoride |
| CAS Number | 353-42-4 |
| Appearance | Clear to pale yellow liquid with a pungent, irritating odor. Fuming liquid that reacts with moisture in air. |
| Flash Point | -14C (7F) |
| Boiling Point | 126-127C (259-261F) |
| Vapor Density | 3.9 (heavier than air) |
| Water Reactivity | Reacts vigorously with water producing toxic hydrogen fluoride gas and flammable vapors; may ignite spontaneously |
Fireground Response Guidance — UN 2965
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and chemical-resistant protective clothing. Level A may be needed for heavy vapor, fuming, splash risk or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 2965 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.
- Keep water or moisture contact controlled because reaction, toxic fuming or re-ignition hazards may be severe.
- 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.
- Prevent contaminated liquid, dust, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 139, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2965 — Boron trifluoride dimethyl etherateUse 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.