☣️ UN 1747 • CLASS 8
UN 1747 — Butyltrichlorosilane
Placard: Corrosive. ERG Guide 155. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ 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.
Butyltrichlorosilane is a highly flammable, corrosive substance used in various industrial applications. It is essential to handle this substance with extreme caution to prevent accidents and injuries.
Hazard overview: Butyltrichlorosilane is highly flammable and can ignite easily, posing explosion hazards. Vapors form explosive mixtures with air, making it a significant indoor, outdoor, and sewer hazard.
Response guidance: In case of an emergency, evacuate the area immediately and call the fire department. Use dry chemical, CO2, or dry sand to extinguish fires, avoiding water or foam directly on the material.
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UN 1747 Quick Details
UN 1747
Product name: Butyltrichlorosilane
DOT Class: 8
Placard type: Corrosive
ERG Guide: 155 (check current ERG)
Initial isolation: ERG 155: Initially isolate 50m in all directions. For large spills, consider initial evacuation of 300m downwind.
Common Hazards of UN 1747
- HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
- Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards.
- Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas
- Vapors may travel to source of ignition and flash back.
- Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
- Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff.
- Corrosives in contact with metals may evolve flammable hydrogen gas.
- Containers may explode when heated or if contaminated with water.
Chemical Identity & Physical Properties
Butyltrichlorosilane is a colorless to pale yellow liquid with a pungent, irritating odor, denser than water, and corrosive, reacting with moisture.
| Also known as | Butyl trichlorosilanen-ButyltrichlorosilaneTrichlorobutylsilaneButylsilicon trichloride |
| CAS Number | 7521-80-4 |
| Appearance | Colorless to pale yellow liquid with a pungent, irritating odor. Corrosive and reacts with moisture. Denser than water. |
| Flash Point | 54°C (129°F) |
| Boiling Point | 148-149°C (298-300°F) |
| Vapor Density | 3.9 (heavier than air) |
| Water Reactivity | Reacts violently with water, releasing hydrochloric acid fumes and heat. Do not apply water directly to material. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1747
Extinguishing Media
Dry chemical, CO2, dry sand. Do not use water or foam directly on material.
PPE Requirements
⚠️ Level B minimum with full face SCBA and chemical-resistant suit. Avoid all skin contact due to corrosivity and water-reactive nature.
Wear Level B minimum personal protective equipment (PPE), including a full-face self-contained breathing apparatus (SCBA) and a chemical-resistant suit, to prevent skin contact and exposure.
Isolation & Evacuation
ERG 155: Initially isolate 50m in all directions. For large spills, consider initial evacuation of 300m downwind.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 155).
First Actions for a UN 1747 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 1747 — ButyltrichlorosilaneHAZMAT RADIO NOTE — UN 1747
Product: Butyltrichlorosilane
Class 8 / Corrosive / ERG 155
PPE: Level B minimum with full face SCBA and chemical-resistant suit. Avoid all skin contact due to corrosivity and water-reactive nature.
ISOLATION: ERG 155: Initially isolate 50m in all directions. For large spills, consider initial evacuation of 300m downwind.
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 1747 — Butyltrichlorosilane
Class: 8 | Placard: Corrosive | ERG Guide: 155
Appearance: Colorless to pale yellow liquid with a pungent, irritating odor. Corrosive and reacts with moisture. Denser than water.
Water Reactivity: Reacts violently with water, releasing hydrochloric acid fumes and heat. Do not apply water directly to material.
Extinguishing: Dry chemical, CO2, dry sand. Do not use water or foam directly on material.
PPE: Level B minimum with full face SCBA and chemical-resistant suit. Avoid all skin contact due to corrosivity and water-reactive nature.
Isolation: ERG 155: Initially isolate 50m in all directions. For large spills, consider initial evacuation of 300m downwind.
— Key Hazards —
• HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
• Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards.
• Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas
— 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/1747 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN1747 Butyltrichlorosilane Cls8 ERG155 | ERG 155: Initially isolate 50m in all directions. For large spills, consider ini | allfirefighter.com/hazmat/un/1747SMS / 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/butyltrichlorosilane-un-1747
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Frequently Asked Questions about UN 1747
Yes, UN 1747 Butyltrichlorosilane is highly flammable and can ignite easily.
UN 1747 Butyltrichlorosilane is highly flammable, corrosive, and can form explosive mixtures with air.
Use dry chemical, CO2, or dry sand to extinguish fires, avoiding water or foam directly on the material.
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.