☣️ UN 3519 • CLASS 2

UN 3519 — Boron trifluoride, adsorbed

Placard: Toxic Gas. ERG Guide 173. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.

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⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.

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.

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UN 3519 Quick Details

UN 3519
Product name: Boron trifluoride, adsorbed
DOT Class: 2
Placard type: Toxic Gas
ERG Guide: 173 (check current ERG)
Initial isolation: ERG 173: Initial isolation 100m in all directions. Protective action distance 0.5km (day) to 1.1km (night) for small spills; 1.4km (day) to 4.2km (night) for large spills.

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 asBoron trifluorideBF3TrifluoroboraneBoron fluorideTrifluoroboron
CAS Number7637-07-2
AppearanceColorless gas with a pungent, suffocating odor. When adsorbed, typically on activated carbon or other solid media. Non-flammable but highly toxic and corrosive.
Flash PointNot applicable (non-flammable gas)
Boiling Point-100.3C (-148.5F)
Vapor Density2.4 (heavier than air)
Water ReactivityReacts violently with water producing toxic and corrosive hydrogen fluoride (HF) and boric acid. Do not use water directly on material.
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 3519

Extinguishing Media

Use agents for surrounding fire and cool containers from protection if safe. Avoid direct water on reactive gases; contain vapor-control water as toxic/corrosive.

PPE Requirements

⚠️ Level A required for gas release or unknown concentrations. Full-face SCBA, chemical-resistant suit with gloves and boots. Avoid skin contact and inhalation at all costs.

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

ERG 173: Initial isolation 100m in all directions. Protective action distance 0.5km (day) to 1.1km (night) for small spills; 1.4km (day) to 4.2km (night) for large spills.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 173).

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.
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📋 Copy & Share Field Card

UN 3519 — Boron trifluoride, adsorbed
HAZMAT RADIO NOTE — UN 3519 Product: Boron trifluoride, adsorbed Class 2 / Toxic Gas / ERG 173 PPE: Level A required for gas release or unknown concentrations. Full-face SCBA, chemical-resistant suit with gloves and boots. Avoid skin contact and inhalation at all costs. ISOLATION: ERG 173: Initial isolation 100m in all directions. Protective action distance 0.5km (day) to 1.1km (night) for small spills; 1.4km (day) to 4.2km (night) for large spills. ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 3519 — Boron trifluoride, adsorbed Class: 2 | Placard: Toxic Gas | ERG Guide: 173 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. Water Reactivity: Reacts violently with water producing toxic and corrosive hydrogen fluoride (HF) and boric acid. Do not use water directly on material. Extinguishing: Use agents for surrounding fire and cool containers from protection if safe. Avoid direct water on reactive gases; contain vapor-control water as toxic/corrosive. PPE: Level A required for gas release or unknown concentrations. Full-face SCBA, chemical-resistant suit with gloves and boots. Avoid skin contact and inhalation at all costs. Isolation: ERG 173: Initial isolation 100m in all directions. Protective action distance 0.5km (day) to 1.1km (night) for small spills; 1.4km (day) to 4.2km (night) for large spills. — Key Hazards — • 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. — First Actions — • 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. SOURCE: allfirefighter.com/hazmat/un/boron-trifluoride-adsorbed-un-3519 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN3519 Boron trifluoride, adsorbed Cls2 ERG173 | allfirefighter.com/hazmat/un/boron-trifluoride-adsorbed-un-3519SMS / 160 CHAR

Use for: Quick text to command or incoming units. Fits in a single SMS.

Open in Messages WhatsApp
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/boron-trifluoride-adsorbed-un-3519

Related UN Numbers in Class 2

Open Class Guide →Hazmat Hub →
UN 1001UN 1002UN 1003UN 1005UN 1006UN 1008UN 1009UN 1011UN 1012UN 1013UN 1016UN 1017
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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Frequently Asked Questions about UN 3519

UN 3519 is Boron trifluoride, adsorbed, assigned to ERG Guide 173.

No. Boron trifluoride, adsorbed is not normally flammable, but it can release toxic/corrosive products in fire or moisture.

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.

Use Level A fully encapsulating chemical protective clothing with positive-pressure SCBA for entry. Zone A toxic gas requires maximum respiratory and skin protection.

Use agents for surrounding fire and cool containers from protection if safe. Avoid direct water on reactive gases; contain vapor-control water as toxic/corrosive.

Adsorption reduces free gas under normal transport, but package damage, heating or valve failure can release toxic gas.

Moisture can form corrosive acids or HF-containing products depending on the gas, creating inhalation and burn hazards.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles. This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.
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