Product Name: N-Octyl(Methyl)Dichlorosilane
Chemical Family: Organosilicon compound
CAS Number: 3429-41-4
Synonyms: Dichloro(n-octyl)methylsilane, n-Octylmethyldichlorosilane
Manufacturer: Always check packaging for manufacturer and emergency contact details
Recommended Uses: Surface modification, water repellency for glass and mineral surfaces, intermediate in the synthesis of other organosilanes
Restrictions on Use: Industrial use only, not for food, drug, or household applications
GHS Classification: Flammable liquids, Category 3; Acute toxicity, Oral Category 4; Skin corrosion/irritation Category 1B; Serious eye damage/irritation Category 1
Hazard Statements: Causes severe skin burns and eye damage; May cause respiratory irritation; Harmful if swallowed; Flammable liquid and vapor
Pictograms: Flame, Corrosion, Exclamation mark
Signal Word: Danger
Precautionary Statements: Keep away from heat/sparks/open flames; Keep container tightly closed; Wash skin thoroughly after handling; Wear protective gloves, clothing, eye and face protection; Avoid breathing vapors or mists; Use only outdoors or in well-ventilated areas
Chemical Identity: N-Octyl(Methyl)Dichlorosilane
CAS Number: 3429-41-4
Concentration: >98%
Impurities: May contain trace amounts of other chlorosilanes
Additives: None intentionally added; check supplier specifications for trace contaminants
Inhalation: Move affected individual to fresh air quickly, keep at rest in position comfortable for breathing. Immediate medical attention is necessary for breathing difficulty or irritation.
Skin Contact: Remove contaminated clothing quickly, flush skin with plenty of water for at least 15 minutes. Immediate medical attention is vital for burns or worsening irritation.
Eye Contact: Rinse eyes immediately with plenty of water for at least 15 minutes keeping eyelids open. Contact a physician right away.
Ingestion: Rinse mouth with water if conscious, do not induce vomiting. Call for emergency medical help immediately.
Main Symptoms: Severe irritation, pain, burns to skin and eyes, difficulty breathing, coughing, stomach pain and nausea after ingestion
Suitable Extinguishing Media: Alcohol-resistant foam, dry chemical, or carbon dioxide work against small fires; large fire situations require water fog for cooling containers only, not direct stream.
Specific Hazards: Vapors are heavier than air, spread along ground, flash back is possible. Reaction with water may produce corrosive hydrogen chloride gases and flammable hydrogen.
Special Protective Equipment: Full protective suit, self-contained breathing apparatus are required in all fire scenarios.
Advice for Firefighters: Remove personnel to safe area. Isolate hazard zone, use firefighting measures from upwind, prevent water and firefighting runoff from entering drains or watercourses.
Personal Precautions: Evacuate unprotected personnel, ventilate the area, control sources of ignition. Wear chemical-resistant gloves, rubber boots, protective suit, and eye/face protection.
Environmental Precautions: Prevent material from entering sewers, surface, or groundwater. If large spills occur near water, notify relevant environmental authorities.
Cleanup Methods: Absorb spills using inert material (vermiculite, dry sand), collect in tightly closed containers. Do not use water to flush spill; reacts violently. Decontaminate area with sodium bicarbonate or lime after cleanup.
Disposal: Dispose collected residues through licensed hazardous waste disposal contractor familiar with chlorosilane chemistry.
Handling: Handle only in chemical fume hoods or well-ventilated areas. Avoid inhalation of vapors/mists. Always use proper PPE such as gloves, face shields, chemical goggles, flame-resistant lab coats, and suitable respirators if ventilation is poor. Avoid contact with water or moisture—chlorosilanes react violently with water.
Storage: Store in cool, dry, well-ventilated places away from water, alcohols, acids, and oxidizers. Keep containers tightly sealed in corrosion-resistant storage cabinets with secondary containment. Use grounding and bonding during transfer to avoid static accumulation.
Occupational Exposure Limits: Consult national and local guidelines—no established values for this compound, but exposure should be minimized.
Engineering Controls: Use fume hoods for all handling. Provide eyewash stations and safety showers in work area.
Personal Protection: Chemical-resistant gloves (nitrile, neoprene, butyl), flame-resistant lab coat, full face shield and goggles, appropriate footwear. Respiratory protection required if vapor/mist expected above low levels.
Hygiene Measures: Always wash hands and face thoroughly after handling and before eating, drinking, or using restrooms.
Appearance: Colorless to light yellow liquid
Odor: Strong, acrid, similar to other chlorosilanes
Odor Threshold: Not well established
pH: Not applicable; reacts with water
Melting/Freezing Point: Below 0°C
Initial Boiling Point/Range: 215–220°C
Flash Point: 88°C (closed cup, approximate)
Evaporation Rate: Not established
Flammability: Flammable liquid and vapor
Vapor Pressure: Low, values available from supplier
Vapor Density: Heavier than air
Solubility: Reacts with water, soluble in most organic solvents
Partition Coefficient (log Kow): Not available
Decomposition Temperature: Decomposes at high temperature producing toxic gases
Viscosity: Not determined
Chemical Stability: Stable only in airtight containers kept away from moisture and incompatible materials.
Reactivity: Highly reactive with water and moist air, releases hydrogen chloride and flammable gases.
Hazardous Reactions: Reacts vigorously or even explosively with water, alcohols, and strong bases. May ignite on contact with moist air or strong oxidizers.
Hazardous Decomposition Products: Hydrogen chloride, silicon oxides, hydrocarbons, and possible methylchloride gases
Acute Toxicity: Oral and dermal LD50 values require reference to manufacturer's data, but classified as harmful if swallowed.
Irritation/Corrosivity: Causes severe burns to skin, eyes, and respiratory tract on exposure.
Sensitization: No evidence of sensitization found in available literature.
Chronic Effects: Repeated exposure can cause chronic respiratory irritation, bronchitis, or chemical pneumonitis.
Routes of Exposure: Skin contact, eye contact, inhalation, ingestion
Symptoms: Severe pain, blistering, burns, shortness of breath, headache, vomiting, pulmonary edema possible after significant exposure
Ecotoxicity: No specific data for this compound, but hydrolysis products (hydrogen chloride and siloxanes) are harmful to aquatic life by rapid acidification and silanization, affecting fish and invertebrates.
Persistence and Degradability: Reacts immediately with water, forming silanols and hydrochloric acid in environment.
Bioaccumulation: Not expected to bioaccumulate significantly—hydrolysis occurs rapidly on contact with moisture.
Mobility: Reacts in soil and water; mobility limited by rapid hydrolysis.
Other Adverse Effects: Acidification of aquatic environments poses a local risk.
Waste Treatment Methods: Destroy by slow hydrolysis and neutralization under controlled conditions. Do not discharge untreated residues into the environment or sewer system.
Container Disposal: Triple-rinse empty containers using suitable solvent, puncture and offer to licensed drum recycler or hazardous waste handler.
Precautions: Work in a chemical fume hood and control runoff to prevent acidification and silanization of wastewater.
UN Number: 2987
UN Proper Shipping Name: Chlorosilanes, flammable, corrosive, n.o.s. (contains n-Octyl(methyl)dichlorosilane)
Transport Hazard Class: 3 (Flammable liquid), 8 (Corrosive)
Packing Group: II
Environmental Hazards: Prevent leakage into environment. If spillage occurs in transit, seek specialist advice.
Special Precautions: Always transport upright and secure. Mark container with hazard labels as per regulations.
Labeling: Classified as hazardous under OSHA Hazard Communication Standard in the US, and under EU CLP regulations. Labels carry GHS pictograms and warning statements.
TSCA: Listed on US Toxic Substances Control Act inventory.
REACH: Subject to registration under European Regulation 1907/2006/EC.
SARA Title III: Check for section 302 (extremely hazardous substances) and 313 (toxic chemicals) applicability.
Other Regional Requirements: Check each country’s chemical safety management legislation for additional storage, reporting, and environmental requirements.
