UN 1731 — Antimony pentachloride, solution
Placard: Corrosive. ERG Guide 157. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1731 is Antimony pentachloride, solution, a toxic corrosive antimony halide assigned to ERG Guide 157. Water or moist air can release corrosive hydrogen halide fumes and toxic antimony contamination.
Hazard overview: UN 1731 presents toxic/corrosive fume, water-reaction and contaminated-runoff hazards. Keep product dry where possible and use ERG, SDS and incident command for entry and control.
Response guidance: For a UN 1731 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 157. Establish incident command, isolate the area, stay upwind, prevent incompatible contact, control runoff and choose entry or fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1731 should emphasize water-reactive corrosive fumes, dry-agent selection, vapor control, ignition control where relevant, runoff containment and decontamination. Use ERG 157, SDS and local SOP.
Regulatory context: Antimony pentachloride, solution 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 concentration, 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: Antimony pentachloride, solution should be stored in tightly closed compatible containers in a cool, dry, well-ventilated area away from water, moisture, bases, oxidizers, ignition sources where relevant and unauthorized access. Protect containers from corrosion, leakage and contamination.
UN 1731 Quick Details
Common Hazards of UN 1731
- TOXIC and CORROSIVE antimony halide; inhalation, ingestion or skin/eye contact may cause severe injury.
- Reacts with water or moist air to release heat and corrosive hydrogen halide fumes.
- Vapors or fumes may accumulate in low or poorly ventilated areas.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff may spread corrosive and toxic antimony contamination.
- Containers may rupture or fail when heated.
- Avoid water contact unless incident command confirms a safe cooling or control use.
Chemical Identity & Physical Properties
Colorless to reddish-yellow liquid solution with a pungent, acrid odor. Fumes in moist air, producing dense white vapors of hydrochloric acid.
| Also known as | Antimony(V) chloride solutionAntimony perchloridePentachloroantimonyAntimonic chloride |
| CAS Number | 7647-18-9 |
| Appearance | Colorless to reddish-yellow liquid solution with a pungent, acrid odor. Fumes in moist air, producing dense white vapors of hydrochloric acid. |
| Flash Point | Not applicable (non-flammable) |
| Boiling Point | 79C (174F) for pure SbCl5; solution varies by concentration |
| Vapor Density | 7.9 (much heavier than air) |
| Water Reactivity | Reacts violently with water, producing heat and toxic/corrosive hydrochloric acid and antimony oxychloride fumes. DO NOT USE WATER. |
Fireground Response Guidance — UN 1731
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fume, fire or confined-space exposure. Chemical-resistant gloves, boots, eye/face protection and protective clothing should be selected from SDS; Level A may be needed for close entry or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 1731 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, fumes, dust or mist and avoid skin or eye contact.
- Keep water and moisture away from the released product unless incident command confirms a compatible cooling or control use.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or leak area and expand the perimeter if vapor, dust, fire involvement, water reaction or unknown concentration is present.
- Use ERG Guide 157, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1731 — Antimony pentachloride, solutionUse 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.