UN 1380 — Pentaborane
Placard: Spontaneously Combustible. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1380 is Pentaborane, a highly toxic spontaneously combustible material assigned to ERG Guide 135. It is a specialist hazmat concern because vapor exposure, pyrophoric ignition and fire products can be severe.
Hazard overview: UN 1380 presents pyrophoric ignition, toxic vapor and fire-product hazards. Responders should treat vapor, smoke and residue as high hazard until monitoring, SDS and incident command confirm safe conditions.
Response guidance: For a UN 1380 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 135. Establish incident command, isolate the area, stay upwind, avoid unnecessary disturbance of powder, piles or damaged packaging, and use only extinguishing agents compatible with the specific material.
Firefighter training notes: Training for UN 1380 should emphasize pyrophoric ignition, extreme toxicity, vapor monitoring, isolation, decontamination and specialist hazmat entry control. Common errors include relying on odor, underestimating vapor spread and treating the material as an ordinary flammable solid.
Regulatory context: Pentaborane is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by formulation, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Pentaborane should be stored only under strict facility procedures in compatible, secured containers away from heat, ignition sources, oxidizers, moisture and incompatible materials. Storage should include ventilation, leak control, monitoring and emergency planning appropriate for toxic pyrophoric materials.
UN 1380 Quick Details
Common Hazards of UN 1380
- SPONTANEOUSLY COMBUSTIBLE and highly toxic; may ignite on exposure to air or moisture.
- Vapors may be flammable and extremely hazardous by inhalation.
- May react vigorously with oxidizers and other incompatible materials.
- Fire may produce toxic boron oxides and other irritating combustion products.
- Containers may rupture or explode when heated.
- Runoff or contaminated equipment may spread toxic residue.
- Treat vapor, fire and contamination areas as high-hazard until monitoring and SDS confirm conditions.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a pungent, acrid odor. Highly reactive and pyrophoric, may ignite spontaneously in moist air at room temperature.
| Also known as | Pentaborane(9)Pentaboron nonahydrideB5H9Stable pentaborane |
| CAS Number | 19624-22-7 |
| Appearance | Colorless to pale yellow liquid with a pungent, acrid odor. Highly reactive and pyrophoric, may ignite spontaneously in moist air at room temperature. |
| Flash Point | -30C (-22F) |
| Boiling Point | 60C (140F) |
| Vapor Density | 2.2 (heavier than air) |
| Water Reactivity | Reacts slowly with water releasing flammable hydrogen gas and forming boric acid; avoid water contact |
Fireground Response Guidance — UN 1380
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and chemical protection selected by hazmat specialists for any potential exposure. Level A may be needed for close entry or unknown concentrations; PPE, monitoring and decontamination should follow SDS and incident command.
Isolation & Evacuation
First Actions for a UN 1380 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away and stay upwind, uphill and/or upstream.
- Avoid all vapor, smoke and liquid contact; do not enter without SCBA and hazmat authorization.
- Eliminate ignition sources only if it can be done from a safe location.
- Isolate the area and use air monitoring when available.
- Ventilate closed spaces only under incident command with proper monitoring and protection.
- Request hazardous materials and technical specialist support early.
- Use ERG Guide 135, shipping papers, SDS and incident command for protective actions and entry decisions.
📋 Copy & Share Field Card
UN 1380 — PentaboraneUse 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.