UN 2604 — Boron trifluoride diethyl etherate
Placard: Corrosive. ERG Guide 132. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2604 is Boron trifluoride diethyl etherate, a flammable corrosive boron trifluoride ether complex assigned to ERG Guide 132. Water can release HF-containing fumes.
Hazard overview: FLAMMABLE and CORROSIVE boron trifluoride ether complex; vapors may ignite and form explosive mixtures with air. Reacts violently with water or moist air, releasing heat and toxic/corrosive hydrogen fluoride-containing fumes. Vapors are heavier than air and may travel to ignition sources and flash back.
Response guidance: For UN 2604, 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 132.
Firefighter training notes: Training for UN 2604 should emphasize water/moisture reaction, toxic/corrosive vapor control, SCBA use, foam/dry-agent choice, decontamination and runoff containment. Use ERG 132, SDS and local SOP.
Regulatory context: Boron trifluoride diethyl etherate 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: Boron trifluoride diethyl etherate 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 2604 Quick Details
Common Hazards of UN 2604
- FLAMMABLE and CORROSIVE boron trifluoride ether complex; vapors may ignite and form explosive mixtures with air.
- Reacts violently with water or moist air, releasing heat and toxic/corrosive hydrogen fluoride-containing fumes.
- Vapors are heavier than air and may travel to ignition sources and flash back.
- Liquid and vapor can burn eyes, skin and respiratory tissue.
- Runoff may be acidic, fluoride-contaminated, corrosive and toxic.
- Fire may produce hydrogen fluoride, boron oxides and irritating/toxic smoke.
- Containers may rupture when heated or contaminated with water.
Chemical Identity & Physical Properties
Clear to pale yellow liquid with a pungent, irritating odor. Fuming in moist air.
| Also known as | Boron trifluoride etherateBF3 diethyl etherateBoron fluoride ethyl ether complexDiethyl etherate of boron trifluoride |
| CAS Number | 109-63-7 |
| Appearance | Clear to pale yellow liquid with a pungent, irritating odor. Fuming in moist air. |
| Flash Point | -18°C (0°F) |
| Boiling Point | 126°C (259°F) |
| Vapor Density | 4.5 (heavier than air) |
| Water Reactivity | Reacts violently with water, releasing toxic and corrosive hydrogen fluoride gas |
Fireground Response Guidance — UN 2604
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 2604 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 132, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2604 — Boron trifluoride diethyl 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.