☣️ UN 1162 • CLASS 3

UN 1162 — Dimethyldichlorosilane

Placard: Flammable. 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.

UN 1162 is Dimethyldichlorosilane, a flammable water-reactive corrosive liquid assigned to ERG Guide 155. It can ignite, fume in moist air and release corrosive hydrogen chloride when exposed to water.

Hazard overview: UN 1162 presents flammable vapor, corrosive fume and violent water-reactivity hazards. Water or moisture can generate heat and dense acid fumes, while vapors may travel to ignition sources and flash back.

Response guidance: For a UN 1162 incident, responders should confirm the product using shipping papers, container markings, SDS and ERG Guide 155. Establish incident command, isolate the area, stay upwind and uphill, remove ignition sources when safe, keep vapors or runoff out of sewers and use compatible Class B fire-control agents from a protected position.

Firefighter training notes: Training for UN 1162 should emphasize flammable vapor behavior, water-reactive corrosive fuming, HCl release, dry-agent selection and runoff control. Common errors include applying water or foam directly, entering without SCBA and ignoring low-area vapor travel. Use ERG 155, SDS and hazmat SOP.

Regulatory context: Dimethyldichlorosilane 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: Dimethyldichlorosilane should be stored in tightly closed compatible containers in a cool, dry, well-ventilated area away from water, moisture, heat, ignition sources, oxidizers and incompatible materials. Protect containers from corrosion, impact and unauthorized access, with dry spill-control materials available where required.

Advertisement

UN 1162 Quick Details

UN 1162
Product name: Dimethyldichlorosilane
DOT Class: 3
Placard type: Flammable
ERG Guide: 155 (check current ERG)
Initial isolation: ERG 155: Isolate spill 50m in all directions. For large spill, isolate 800m downwind. Evacuate immediate area if fire involved.

Common Hazards of UN 1162

  • HIGHLY FLAMMABLE and WATER-REACTIVE; vapors may form explosive mixtures with air.
  • Reacts with water or moisture to release heat and corrosive hydrogen chloride fumes.
  • Vapors are heavier than air and may travel to ignition sources and flash back.
  • Liquid and fumes are corrosive to eyes, skin and respiratory tissue.
  • Fire may produce irritating, corrosive and/or toxic gases.
  • Runoff or water contact may spread corrosive contamination.
  • Containers may rupture or explode when heated or contaminated with water.

Chemical Identity & Physical Properties

Colorless to pale yellow fuming liquid with a pungent, irritating, hydrochloric acid-like odor. Reacts violently with water, producing dense white fumes of hydrochloric acid.

Also known asDichlorodimethylsilaneDimethyldichlorosilaneDMDCSSilane, dichlorodimethyl-
CAS Number75-78-5
AppearanceColorless to pale yellow fuming liquid with a pungent, irritating, hydrochloric acid-like odor. Reacts violently with water, producing dense white fumes of hydrochloric acid.
Flash Point-16C (3F)
Boiling Point70C (158F)
Vapor Density4.4 (heavier than air)
Water ReactivityReacts violently with water, producing hydrochloric acid and heat. DO NOT USE WATER directly on material.
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 1162

Extinguishing Media

Use dry chemical, CO2 or dry sand only if compatible and directed by incident command; do not apply water or foam directly to the material.

PPE Requirements

⚠️ Level B minimum with SCBA required. Full chemical-resistant suit for spill response. Butyl rubber or Viton gloves recommended.

Use positive-pressure SCBA for vapor, fire or confined-space exposure. Chemical-resistant protective clothing, gloves, boots and eye/face protection should be selected from SDS and incident command because fumes and liquid are corrosive and water-reactive.

Isolation & Evacuation

ERG 155: Isolate spill 50m in all directions. For large spill, isolate 800m downwind. Evacuate immediate area if fire involved.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 155).

First Actions for a UN 1162 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.
  • Eliminate ignition sources if it is safe to do so.
  • Do not touch or walk through spilled liquid unless properly trained and wearing appropriate protective equipment.
  • Avoid breathing vapors and avoid skin or eye contact with liquid.
  • Keep water away from the released material unless incident command confirms a compatible use for cooling or vapor control.
  • Ventilate closed spaces before entering, but only if properly trained, equipped and authorized by incident command.
  • Isolate the spill or leak area for at least 50 meters (150 feet) in all directions.
  • For large spills, fire involvement or strong vapor movement, expand isolation and consider downwind evacuation based on monitoring and incident command.
  • Use ERG Guide 155, shipping papers, SDS and local SOP for protective actions and entry decisions.
Advertisement

📋 Copy & Share Field Card

UN 1162 — Dimethyldichlorosilane
HAZMAT RADIO NOTE — UN 1162 Product: Dimethyldichlorosilane Class 3 / Flammable / ERG 155 PPE: Level B minimum with SCBA required. Full chemical-resistant suit for spill response. Butyl rubber or Viton gloves recommended. ISOLATION: ERG 155: Isolate spill 50m in all directions. For large spill, isolate 800m downwind. Evacuate immediate area if fire involved. ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 1162 — Dimethyldichlorosilane Class: 3 | Placard: Flammable | ERG Guide: 155 Appearance: Colorless to pale yellow fuming liquid with a pungent, irritating, hydrochloric acid-like odor. Reacts violently with water, producing dense white fumes of hydrochloric acid. Water Reactivity: Reacts violently with water, producing hydrochloric acid and heat. DO NOT USE WATER directly on material. Extinguishing: Use dry chemical, CO2 or dry sand only if compatible and directed by incident command; do not apply water or foam directly to the material. PPE: Level B minimum with SCBA required. Full chemical-resistant suit for spill response. Butyl rubber or Viton gloves recommended. Isolation: ERG 155: Isolate spill 50m in all directions. For large spill, isolate 800m downwind. Evacuate immediate area if fire involved. — Key Hazards — • HIGHLY FLAMMABLE and WATER-REACTIVE; vapors may form explosive mixtures with air. • Reacts with water or moisture to release heat and corrosive hydrogen chloride fumes. • Vapors are heavier than air and may travel to ignition sources and flash back. — First Actions — • 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. • Eliminate ignition sources if it is safe to do so. SOURCE: allfirefighter.com/hazmat/un/dimethyldichlorosilane-un-1162 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN1162 Dimethyldichlorosilane Cls3 ERG155 | allfirefighter.com/hazmat/un/dimethyldichlorosilane-un-1162SMS / 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/dimethyldichlorosilane-un-1162

Related UN Numbers in Class 3

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
Advertisement

Frequently Asked Questions about UN 1162

UN 1162 is Dimethyldichlorosilane, a hazardous material assigned to ERG Guide 155.

Yes. It is flammable and vapors may form explosive mixtures with air; it also reacts dangerously with water.

ERG Guide 155 applies to UN 1162 and should be used for initial isolation, protective actions and first response guidance.

UN 1162 presents flammable vapor, corrosive fume and violent water-reactivity hazards. Water or moisture can generate heat and dense acid fumes, while vapors may travel to ignition sources and flash back.

Use positive-pressure SCBA for vapor, fire or confined-space exposure. Chemical-resistant protective clothing, gloves, boots and eye/face protection should be selected from SDS and incident command because fumes and liquid are corrosive and water-reactive.

Responders should isolate the area, stay upwind and uphill, eliminate ignition sources when safe, prevent sewer entry, verify the product with SDS and follow ERG Guide 155, incident command and local SOP.
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.