Product Name: N-Octadecyltrimethoxysilane
Chemical Formula: C21H46O3Si
CAS Number: 3069-42-9
Synonyms: Trimethoxy(octadecyl)silane, Stearyltrimethoxysilane
Recommended Use: Surface modifier, hydrophobic treatment for glass and mineral surfaces, coupling agent in adhesives and sealants
Supplier Contact: Customer Service, [Company Name Omitted], [Address], [Phone Number], [Email]
Emergency Contact: Chemtrec: [Phone Number]
Classification: Flammable liquids (Category 3), Skin irritation (Category 2), Eye irritation (Category 2A), Specific target organ toxicity—single exposure (Category 3)
Signal Word: Warning
Hazard Statements: Combustible liquid. Causes skin irritation. Causes serious eye irritation. May cause respiratory irritation.
Pictograms: Flame, Exclamation mark
Precautionary Statements: Keep away from heat, sparks, open flames. Wear protective gloves, goggles, and clothing. Avoid breathing vapors or mists. Wash exposed skin thoroughly. If on skin or in eyes, rinse well with water. Use only outdoors or in well-ventilated area.
Chemical Name: Trimethoxy(octadecyl)silane
CAS Number: 3069-42-9
Purity: ≥ 98%
Impurities: Methanol (potential hydrolysis byproduct), less than 0.5%
Inhalation: Move affected person to fresh air. If breathing becomes difficult, provide oxygen. Seek medical attention if symptoms persist.
Skin Contact: Wash affected area with plenty of soap and water for at least 15 minutes. Remove contaminated clothing. Seek medical attention if irritation develops.
Eye Contact: Rinse gently with water for at least 15 minutes, occasionally lifting eyelids. Seek medical attention for persistent redness or discomfort.
Ingestion: Rinse mouth thoroughly with water. Do not induce vomiting. Give water to drink if conscious. Seek immediate medical help.
Suitable Extinguishing Media: Use carbon dioxide, dry chemical powder, alcohol-resistant foam.
Unsuitable Extinguishing Media: Direct water stream can spread fire.
Specific Hazards: Vapors may form explosive mixtures with air. Combustion generates carbon oxides, silicon oxides, and formaldehyde.
Protective Equipment: Use full protective gear with self-contained breathing apparatus. Avoid inhaling combustion products.
Special Procedures: Isolate fire area. Cool containers with water spray to prevent pressure build-up. Remove undamaged containers from fire zone if safe to do so.
Personal Precautions: Prevent skin and eye contact. Avoid inhaling vapors. Ventilate area. Remove ignition sources.
Environmental Precautions: Prevent entry into drains, waterways, or soil.
Containment and Cleaning: Absorb spillage with inert material (sand, earth, vermiculite). Place in tightly sealed container for disposal. Wash spill area thoroughly after clean-up with detergent and water.
Handling: Wear recommended PPE: gloves, goggles, and protective clothing. Work in well-ventilated area. Avoid creating aerosols or breathing vapor. Ground and bond containers when transferring. Use proper procedures to minimize splashing and exposure.
Storage: Store in tightly closed container in cool, dry, well-ventilated place away from sources of ignition and incompatible materials. Keep away from moisture and direct sunlight. Do not store near oxidizers, acids, or bases. Store at recommended temperature range (2–8°C).
Engineering Controls: Provide local exhaust ventilation to minimize vapor concentrations. Use explosion-proof equipment for flammable substances.
Personal Protection: Wear safety goggles or full-face shield, solvent-resistant gloves, lab coat or apron. In case of inadequate ventilation, use NIOSH-approved respirator.
Hygiene: Wash hands after handling. Remove contaminated clothing before re-entering eating/drinking areas. Shower after work.
Appearance: Colorless to pale yellow liquid
Odor: Mild, fatty
Odor Threshold: Data unavailable
pH: Not applicable
Melting Point/Freezing Point: 16–20°C (solidifies near room temperature)
Boiling Point: 195–205°C
Flash Point: Approximately 93°C (closed cup)
Evaporation Rate: Slow
Flammability: Combustible
Vapor Pressure: <1 mmHg at 20°C
Vapor Density: >1 (Air = 1)
Relative Density: 0.88–0.90 g/cm³ at 25°C
Solubility: Insoluble in water; soluble in organic solvents (toluene, hexane)
Partition coefficient (n-octanol/water): Estimated high log Kow
Autoignition Temperature: Not determined
Decomposition Temperature: Not determined
Viscosity: 4–6 cP at 25°C
Chemical Stability: Stable under recommended storage conditions.
Reactivity: Reacts with water or moisture to release methanol.
Incompatible Materials: Strong oxidizing agents, acids, bases, moisture.
Hazardous Decomposition: Produces carbon oxides, silicon oxides, methanol on thermal decomposition.
Hazardous Polymerization: Does not occur under normal use.
Acute Toxicity: Low toxicity by oral, dermal, or inhalation routes. Oral LD50 (rat) > 5000 mg/kg (estimated for silane family).
Skin Corrosion/Irritation: Causes skin irritation—may result in redness and discomfort.
Eye Damage/Irritation: Causes eye irritation—may lead to tearing, redness.
Respiratory Sensitization: Prolonged or repeated exposure to high vapor levels can lead to respiratory irritation.
Chronic Effects: Methanol released on hydrolysis is toxic by ingestion, inhalation or skin absorption, affecting nervous system and vision.
Carcinogenicity: Not classified as carcinogen by IARC, NTP, or OSHA.
Mutagenicity/Teratogenicity: Inadequate data available for silane family.
Other Effects: No available data for reproductive effects, delayed effects, or target organ effects specific to this product.
Ecotoxicity: Not classified as acutely toxic to aquatic organisms. Methanol hydrolysis byproduct hazardous to aquatic life.
Persistence and Degradability: Limited biodegradability; hydrolyzes slowly in environmental conditions.
Bioaccumulation: Potential to bioaccumulate based on high log Kow.
Mobility in Soil: Low due to hydrophobic chain; binds strongly to sediments and particulates.
Other Adverse Effects: Avoid discharge to aquatic environments and public water systems.
Waste Treatment Methods: Dispose of in accordance with local, regional, and national regulations. Do not pour down the drain.
Incineration: Send to licensed chemical incinerator with afterburner and scrubber.
Contaminated Packaging: Empty containers may retain hazardous residue; dispose as hazardous waste.
Avoid: Uncontrolled release to environment or mixing with incompatible waste.
UN Number: UN 1993
UN Proper Shipping Name: Flammable liquid, n.o.s. (contains N-Octadecyltrimethoxysilane)
Transport Hazard Class: 3
Packing Group: III
Hazard Labels: Flammable liquid
Marine Pollutant: No
Special Precautions: Ensure containers are upright and well-sealed during transport. Avoid extreme heat or flame exposure.
Inventory Status: Listed on TSCA (USA), DSL (Canada), REACH (EU), AICS (Australia), ENCS (Japan)
Safety, Health, and Environmental Regulations: Subject to OSHA Hazard Communication Standard, SARA Title III (USA), and related workplace safety rules
Worker Protection: Follow GHS-compliant labeling and SDS handling instructions. Consult local laws for storage and transport restrictions.
Other Regulations: Ensure compliance with local regulations regarding chemical classification, workplace exposure, and waste management.
