UN 3519 — Boron trifluoride, adsorbed
Placard: Toxic Gas. ERG Guide 173. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3519 At a Glance
UN 3519 (Boron trifluoride, adsorbed) is listed as DOT Class 2 Toxic Gas and is assigned to ERG Guide 173. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
UN 3519 is Boron trifluoride, adsorbed, a toxic corrosive adsorbed BF3 gas assigned to ERG Guide 173. Moisture can form HF-containing corrosive fumes.
Hazard overview: TOXIC and CORROSIVE boron trifluoride gas adsorbed on a porous solid; inhalation may be fatal. Reacts vigorously with water or moisture to form hydrogen fluoride and boric acid. HF-containing fumes can cause severe respiratory injury and deep tissue fluoride burns.
Response guidance: For UN 3519, isolate downwind/low areas, treat as a life-threatening gas release and use Level A/SCBA for entry. Verify exact gas with shipping papers and ERG 173.
Firefighter training notes: Training for UN 3519 should emphasize toxic-gas recognition, Zone A isolation, Level A/SCBA entry, air monitoring, source-control limits and decontamination. Use ERG 173, SDS and local SOP.
Regulatory context: Boron trifluoride, adsorbed is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, package type, gas identity and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Boron trifluoride, adsorbed should be stored in secured compatible adsorbed-gas packages away from heat, impact, corrosion, moisture where incompatible and unauthorized access, with ventilation and emergency planning.
UN 3519 Quick Details
Common Hazards of UN 3519
- TOXIC and CORROSIVE boron trifluoride gas adsorbed on a porous solid; inhalation may be fatal.
- Reacts vigorously with water or moisture to form hydrogen fluoride and boric acid.
- HF-containing fumes can cause severe respiratory injury and deep tissue fluoride burns.
- Released gas is heavier than air and may collect in low or confined areas.
- Gas is non-flammable, but fire may heat containers and release toxic/corrosive gas.
- Runoff or vapor-control water may be fluoride-contaminated and corrosive.
- Package damage, heat or valve failure can release free BF3 gas.
Chemical Identity & Physical Properties
Colorless gas with a pungent, suffocating odor. When adsorbed, typically on activated carbon or other solid media. Non-flammable but highly toxic and corrosive.
| Also known as | Boron trifluorideBF3TrifluoroboraneBoron fluorideTrifluoroboron |
| CAS Number | 7637-07-2 |
| Appearance | Colorless gas with a pungent, suffocating odor. When adsorbed, typically on activated carbon or other solid media. Non-flammable but highly toxic and corrosive. |
| Flash Point | Not applicable (non-flammable gas) |
| Boiling Point | -100.3C (-148.5F) |
| Vapor Density | 2.4 (heavier than air) |
| Water Reactivity | Reacts violently with water producing toxic and corrosive hydrogen fluoride (HF) and boric acid. Do not use water directly on material. |
Fireground Response Guidance — UN 3519
Extinguishing Media
PPE Requirements
Use Level A fully encapsulating chemical protective clothing with positive-pressure SCBA for entry. Zone A toxic gas requires maximum respiratory and skin protection.
Isolation & Evacuation
First Actions for a UN 3519 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind and avoid low or poorly ventilated areas unless monitoring shows they are safe.
- Treat the release as a life-threatening inhalation hazard until the gas is identified and monitored.
- Do not handle leaking cylinders, adsorbed-gas packages or damaged gas articles without proper training and PPE.
- Ventilate only after monitoring and only if properly trained and equipped.
- Use ERG Guide 173, shipping papers, markings and air monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3519 — Boron trifluoride, adsorbedUse 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.