UN 1766 — Dichlorophenyltrichlorosilane
Placard: Corrosive. ERG Guide 156. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1766 is Dichlorophenyltrichlorosilane, a corrosive hazardous material assigned to ERG Guide 156. Responders should verify the exact product with shipping papers, container markings and SDS before close action.
Hazard overview: UN 1766 presents corrosive exposure hazards and may create toxic/corrosive gases or runoff in fire or incompatible contact. Use ERG, SDS and incident command to set isolation, PPE and control actions.
Response guidance: For a UN 1766 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 156. 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 1766 should emphasize corrosive exposure routes, water or oxidizer incompatibility where applicable, air monitoring, PPE selection, decontamination and runoff containment. Use ERG 156, SDS and local SOP.
Regulatory context: Dichlorophenyltrichlorosilane is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, pesticide/waste handling where applicable, storage and environmental requirements may vary by formulation, concentration, 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: Dichlorophenyltrichlorosilane should be stored in tightly closed compatible containers in a secure, cool, dry, well-ventilated hazardous-material area according to SDS and local procedures.
UN 1766 Quick Details
Common Hazards of UN 1766
- CORROSIVE material; inhalation, ingestion or skin/eye contact may cause severe injury.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff may be corrosive and may pollute waterways.
- Containers may rupture or fail when heated.
- Specific hazards depend on the exact product, concentration and SDS.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a pungent, acrid odor. Corrosive liquid at room temperature, fumes in moist air.
| Also known as | Dichlorophenyl trichlorosilaneTrichlorodichlorophenylsilanePhenyl dichlorotrichlorosilaneDichlorophenyltrichlorosilane (various isomers) |
| CAS Number | 27137-85-5 |
| Appearance | Colorless to pale yellow liquid with a pungent, acrid odor. Corrosive liquid at room temperature, fumes in moist air. |
| Flash Point | Not readily ignitable but combustible; flash point data varies by isomer, generally >93C (>200F) |
| Boiling Point | Approximately 260-280C (500-536F), varies by isomer position |
| Vapor Density | Approximately 9-10 (much heavier than air) |
| Water Reactivity | Reacts violently with water, releasing toxic and corrosive HCl gas and heat. Do not use water directly on material. |
Fireground Response Guidance — UN 1766
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, mist, dust, fire or confined-space exposure. Chemical-resistant gloves, boots, eye/face protection and protective clothing should be selected from SDS.
Isolation & Evacuation
First Actions for a UN 1766 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, mist or spray and avoid skin or eye contact.
- 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 156, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1766 — DichlorophenyltrichlorosilaneUse 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.