☣️ UN 3420 • CLASS 8
UN 3420 — Boron trifluoride propionic acid complex, solid
Placard: Corrosive. ERG Guide 157. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ Verification required:
Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ 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 3420 is Boron trifluoride propionic acid complex, solid, a highly corrosive boron trifluoride acid complex. It is moisture-sensitive and can release toxic acidic vapors when exposed to water or humid air.
Hazard overview: UN 3420 can cause severe burns and respiratory injury. Water contact may generate heat and release hydrogen fluoride and organic acid vapors. Fire can produce toxic, corrosive gases and containers may become hazardous when heated.
Response guidance: For UN 3420, isolate the area, keep the product dry and avoid water or foam. Use dry chemical, soda ash, lime or dry sand when compatible and safe. Evacuate downwind areas if fuming, fire or large release is present.
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UN 3420 Quick Details
UN 3420
Product name: Boron trifluoride propionic acid complex, solid
DOT Class: 8
Placard type: Corrosive
ERG Guide: 157 (check current ERG)
Initial isolation: ERG 157: isolate spill 25-50m all directions; if tank/rail car involved in fire isolate 800m all directions; evacuate initial downwind 300m for small spill, 1000m for large spill
Common Hazards of UN 3420
- TOXIC and/or CORROSIVE; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance
- Reaction with water or moist air may release toxic, corrosive or flammable gases.
- Reaction with water may generate much heat that will increase the concentration of fumes in the air.
- Fire will produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental
- Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive
- UN1802, UN2032, UN3084, UN3093, UN1796 (above 50%), UN1826 (above 50%), and UN2031 (above
- Vapors may accumulate in confined areas (basement, tanks, hopper/tank cars, etc.).
Chemical Identity & Physical Properties
UN 3420 is usually a white to off-white crystalline solid with a pungent acrid odor. It is hygroscopic and may fume in moist air.
| Also known as | Boron trifluoride propanoic acid complexBF3 propionic acid complexBoron trifluoride-propionic acid adduct |
| Appearance | White to off-white crystalline solid with a pungent, acrid odor. Highly corrosive and hygroscopic material that fumes in moist air. |
| Flash Point | Not applicable (solid) |
| Boiling Point | Decomposes before boiling |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts vigorously with water releasing corrosive and toxic hydrogen fluoride (HF) gas and heat; avoid water contact |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3420
Extinguishing Media
Dry chemical, soda ash, lime; no water or foam
PPE Requirements
⚠️ Level A recommended; full encapsulating suit with SCBA required; chemical-resistant gloves; avoid all contact with material and vapors
Level A protection is recommended for uncontrolled releases or visible fuming. At minimum, use positive-pressure SCBA with acid/fluoride-resistant suit, gloves and boots.
Isolation & Evacuation
ERG 157: isolate spill 25-50m all directions; if tank/rail car involved in fire isolate 800m all directions; evacuate initial downwind 300m for small spill, 1000m for large spill
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 157).
First Actions for a UN 3420 Incident
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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📋 Copy & Share Field Card
UN 3420 — Boron trifluoride propionic acid complexHAZMAT RADIO NOTE — UN 3420
Product: Boron trifluoride propionic acid complex, solid
Class 8 / Corrosive / ERG 157
PPE: Level A recommended; full encapsulating suit with SCBA required; chemical-resistant gloves; avoid all contact with material and vapors
ISOLATION: ERG 157: isolate spill 25-50m all directions; if tank/rail car involved in fire isolate 800m all directions; evacuate initial downwind 300m for small spill, 1000m for large spill
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 3420 — Boron trifluoride propionic acid complex, solid
Class: 8 | Placard: Corrosive | ERG Guide: 157
Appearance: White to off-white crystalline solid with a pungent, acrid odor. Highly corrosive and hygroscopic material that fumes in moist air.
Water Reactivity: Reacts vigorously with water releasing corrosive and toxic hydrogen fluoride (HF) gas and heat; avoid water contact
Extinguishing: Dry chemical, soda ash, lime; no water or foam
PPE: Level A recommended; full encapsulating suit with SCBA required; chemical-resistant gloves; avoid all contact with material and vapors
Isolation: ERG 157: isolate spill 25-50m all directions; if tank/rail car involved in fire isolate 800m all directions; evacuate initial downwind 300m for small spill, 1000m for large spill
— Key Hazards —
• TOXIC and/or CORROSIVE; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance
• Reaction with water or moist air may release toxic, corrosive or flammable gases.
• Reaction with water may generate much heat that will increase the concentration of fumes in the air.
— First Actions —
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Ventilate closed spaces before entering, but only if properly trained and equipped.
• Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
SOURCE: allfirefighter.com/hazmat/un/boron-trifluoride-propionic-acid-un-3420 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN3420 Boron trifluoride propionic acid complex, solid Cls8 ERG157 | allfirefighter.com/hazmat/un/boron-trifluoride-propionic-acid-un-3420SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/boron-trifluoride-propionic-acid-un-3420
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Frequently Asked Questions about UN 3420
UN 3420 is Boron trifluoride propionic acid complex, solid. It should be identified from shipping papers, markings and the SDS before responders work near the release.
ERG Guide 157 applies to UN 3420 for initial isolation, protective actions and first-response guidance.
UN 3420 is not primarily classified as flammable, but fire may produce toxic or corrosive gases and containers may become dangerous when heated.
Level A protection is recommended for uncontrolled releases or visible fuming. At minimum, use positive-pressure SCBA with acid/fluoride-resistant suit, gloves and boots.
UN 3420 can cause severe burns and respiratory injury.
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.