UN 2676 — Stibine
Placard: Toxic Gas. ERG Guide 119. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2676 is Stibine, an extremely toxic flammable gas assigned to ERG Guide 119. Inhalation, flashback and low-area accumulation are critical hazards.
Hazard overview: EXTREMELY TOXIC and FLAMMABLE compressed gas; inhalation may be fatal. Gas can form explosive mixtures with air and flash back from ignition sources. Vapors are heavier than air and may collect in low or confined areas.
Response guidance: For UN 2676, isolate the release, eliminate ignition sources and use SCBA with chemical protection. Stop gas flow only if safe; do not extinguish a leaking gas fire unless flow can be stopped.
Firefighter training notes: Training for UN 2676 should emphasize toxic flammable gas behavior, source isolation, air monitoring, no-extinguishment-until-flow-stopped tactics, cylinder cooling and decontamination. Use ERG 119, SDS and local SOP.
Regulatory context: Stibine 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: Stibine cylinders should be secured in a cool, ventilated toxic-gas storage area away from heat, ignition sources, physical damage and incompatible materials. Provide gas detection and emergency planning.
UN 2676 Quick Details
Common Hazards of UN 2676
- EXTREMELY TOXIC and FLAMMABLE compressed gas; inhalation may be fatal.
- Gas can form explosive mixtures with air and flash back from ignition sources.
- Vapors are heavier than air and may collect in low or confined areas.
- Liquefied gas contact can cause frostbite or cold burns.
- Fire may produce antimony oxide fumes and other toxic gases.
- Cylinders exposed to fire may vent, rupture or rocket.
- Do not rely on odor as a safe warning of exposure.
Chemical Identity & Physical Properties
Colorless gas with an unpleasant, garlic-like or fishy odor. Heavier than air and may accumulate in low-lying areas.
| Also known as | Antimony hydrideAntimony trihydrideHydrogen antimonide |
| CAS Number | 7803-52-3 |
| Appearance | Colorless gas with an unpleasant, garlic-like or fishy odor. Heavier than air and may accumulate in low-lying areas. |
| Flash Point | Not applicable (flammable gas) |
| Boiling Point | -17C (1F) |
| Vapor Density | 4.35 (much heavier than air) |
| Water Reactivity | Decomposes slowly in water, releasing antimony compounds |
Fireground Response Guidance — UN 2676
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and fully encapsulating chemical protective clothing for close entry or unknown concentrations. Protect against toxic gas, fire and frostbite.
Isolation & Evacuation
First Actions for a UN 2676 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 keep people out of low or poorly ventilated areas.
- Eliminate ignition sources if safe and do not extinguish a leaking gas fire unless flow can be stopped.
- Treat the release as an inhalation hazard until monitoring proves otherwise.
- Do not touch leaking cylinders or liquefied gas without proper training and PPE.
- Use ERG Guide 119, SDS, cylinder markings and air monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2676 — StibineUse 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.