Product Name: Octylmethyldimethoxysilane
Chemical Formula: C11H26O2Si
Synonyms: Methoxy(trimethylsiloxy)octane, Dimethoxy(octyl)methylsilane
CAS Number: 3069-40-7
Manufacturer: Common sources include major chemical suppliers across the globe.
Recommended Uses: Surface treatment, water-repellency agents, construction coatings, electronic device fabrication.
Contact Information: Refer directly to supplier’s MSDS for specific emergency contacts.
GHS Classification: Flammable liquids (Category 3), Acute toxicity (Category 4, inhalation), Eye irritation (Category 2A), Skin irritation (Category 2)
Signal Word: Warning
Hazard Statements: Flammable liquid and vapor. Harmful if inhaled. Causes skin and eye irritation. May cause respiratory irritation.
Precautionary Statements: Keep away from heat, sparks, open flames. Provides adequate ventilation. Wear protective gloves and eye protection.
Pictograms: Flammable, Exclamation mark (for irritation)
Chemical Name: Octylmethyldimethoxysilane
CAS Number: 3069-40-7
Concentration: 100% (usually supplied neat)
Impurities: Trace amounts of related silanes or alcohol by-products possible.
Additives: Typically absent, unless noted otherwise on product-specific safety data sheets.
Inhalation: Move person to fresh air immediately. Seek medical attention if irritation or breathing difficulty continues.
Skin Contact: Remove contaminated clothing. Rinse skin thoroughly with soap and water for at least 15 minutes.
Eye Contact: Rinse cautiously with water for several minutes, lifting upper and lower eyelids occasionally. Continue rinsing and seek medical care if irritation persists.
Ingestion: Do not induce vomiting. Rinse mouth with water if conscious. Call poison control or get immediate medical assistance.
Notes for Physicians: Treat symptomatically. Watch for delayed effects on respiratory system or skin.
Suitable Extinguishing Media: Water mist, dry chemical powder, foam, or carbon dioxide. Avoid full water jet.
Specific Hazards: Releases flammable vapors at room temperature, potential to cause vapor-air explosions in enclosed spaces. Can evolve toxic gases such as carbon oxides and silicon oxides during combustion.
Protective Equipment for Firefighters: Wear self-contained breathing apparatus, chemical-resistant clothing, full face shield, gloves, and boots.
Further Advice: Cool containers exposed to fire with water spray from a safe distance. Remove ignition sources and minimize exposure to combustion by-products.
Personal Precautions: Evacuate area if vapor concentrations approach flammable limits. Wear suitable gloves, goggles, and respiratory protection.
Environmental Precautions: Prevent further leakage or spillage if safe to do so. Avoid entry into drains, surface water, or soils.
Methods for Clean-Up: Absorb spills with inert material such as sand, diatomaceous earth, or universal binder. Collect in closed containers for disposal. Ventilate the area well.
Decontamination Procedures: Wash spill site after removal of material. Use non-sparking tools and grounded equipment.
Handling: Work in a chemical fume hood if possible. Use spark-proof equipment, ensure good ventilation, avoid all sources of ignition. Ground all containers during transfer to prevent static charge.
Storage Conditions: Store in tightly sealed original containers in cool, dry, well-ventilated premises. Keep away from incompatible materials including strong oxidizers, acids, and bases.
Specific Storage Requirements: Store away from direct sunlight, moisture, and out of reach of untrained personnel. Label all storage vessels correctly.
Inventory Management: Periodically inspect containers for damage, leaks, or signs of decomposition.
Engineering Controls: Use local exhaust ventilation to maintain vapor concentrations below recommended exposure limits.
Occupational Exposure Limits: No official OSHA or ACGIH standards, but minimize exposure by best available means.
Personal Protection: Wear chemical-resistant gloves such as butyl rubber or nitrile, safety goggles, lab coat, and appropriate footwear. If exposure risk is high, consider full-face respirator with organic vapor cartridges.
Hygiene Measures: Wash hands thoroughly after handling, take off any contaminated clothing and clean before reuse. No eating, drinking, or smoking in work area.
Monitoring: Consider regular air monitoring for personnel in high-use settings.
Appearance: Clear, colorless to pale yellow liquid
Odor: Slight, alcohol-like aroma
Melting Point: Below room temperature, detail not well established
Boiling Point: Approximately 220°C (428°F)
Flash Point: About 81°C (178°F), closed cup
Evaporation Rate: Moderate, similar to related silane compounds
Flammability: Flammable in liquid and vapor phase
Vapor Pressure: Low, increases with temperature
Solubility: Not miscible with water, hydrolyzes slowly in contact with water; soluble in organic solvents like alcohols, ethers
Density: 0.85–0.88 g/cm³ at 25°C
Partition Coefficient: Log Kow estimated around 5 to 7, suggesting preferential partitioning into organic phases
Autoignition Temperature: Above 250°C (482°F)
Decomposition Temperature: Thermal breakdown can liberate methanol and silicon oxides.
Viscosity: Low viscosity, flows easily in standard lab environments.
Chemical Stability: Stable under standard temperatures, inert to most common laboratory plastics and glassware.
Reactivity: Reacts with water, moisture, acids and strong oxidizing agents.
Hazardous Reactions: Contact with moisture or water triggers hydrolysis, releasing methanol.
Conditions to Avoid: Avoid exposure to heat, open flames, sparks, static discharge, and direct sunlight.
Incompatible Materials: Avoid strong acids, bases, oxidizing agents, and moisture.
Hazardous Decomposition Products: Methanol, formaldehyde, silicon oxides.
Acute Toxicity: May cause headaches, dizziness, coughing, respiratory discomfort, or drowsiness if inhaled. Oral and dermal toxicity considered low, but ingesting or breathing concentrated vapors can lead to more severe symptoms.
Chronic Effects: Prolonged or repeated skin contact may lead to dermatitis. Repeated significant exposure risks targeting liver and kidneys due to methanol by-product.
Skin Corrosion/Irritation: Moderate, requires prompt washing.
Serious Eye Damage/Irritation: Moderate, leads to redness and discomfort.
Respiratory or Skin Sensitization: Not classified as sensitizer but avoid repeated direct exposure.
Carcinogenicity: Not listed by IARC, NTP, or OSHA.
Mutagenicity/Teratogenicity: Data insufficient for robust assessment.
Other Effects: Methanol vapor may induce delayed systemic toxicity if hydrolysis occurs.
Ecotoxicity: This chemical displays moderate aquatic toxicity. Spills can affect aquatic organisms due to both silane and methanol released on hydrolysis.
Persistence and Degradability: Hydrolyzes slowly, breaking down into methanol and organosilicon by-products.
Bioaccumulation Potential: High log Kow indicates possibility of bioaccumulation, especially for aquatic organisms.
Mobility in Soil: Binds moderately to organic matter, can migrate if released in large quantities.
Other Adverse Effects: Avoid unintentional release into water bodies and soil to protect aquatic ecosystems.
Waste Disposal Methods: Dispose according to local, national, and regional regulations. Large volumes should be incinerated in chemical incinerators equipped with afterburner and scrubber.
Contaminated Packaging: Empty containers should be triple-rinsed with compatible solvent before disposal or recycling.
Environmental Precautions: Avoid discharge into drains, surface water, or the environment.
Additional Advice: Check with hazardous waste authorities for best disposal practices in your region.
UN Number: UN 1993
Proper Shipping Name: Flammable Liquid, n.o.s. (Octylmethyldimethoxysilane)
Transport Hazard Class: 3 (Flammable Liquid)
Packing Group: III
Marine Pollutant: No specific data available, handle with care to avoid spills in transit.
Special Precautions: Ensure upright securement during transit, inspection for leaks or damage, use properly labeled containers.
Regulatory Transport Guidance: Comply with all DOT (US), IMDG (sea), and IATA (air) regulations.
TSCA Status: Listed on US Toxic Substances Control Act Inventory
REACH Registration: Registered for various uses in EU where applicable
SARA Title III: Not specifically listed, but methanol by-product can trigger reporting in large accidental releases
California Proposition 65: Methanol present as a by-product is listed
WHMIS Classification: B2 (Flammable Liquid), D2B (Toxic Material Causing Other Toxic Effects) in Canada
Other Relevant Regulations: Country-specific workplace exposure and environmental restriction laws may apply. Always consult the local regulatory requirements and review supplier safety data for the most up-to-date legal obligations.
