Product Name: Methyltriethoxysilane
Other Names: Triethoxymethylsilane
CAS Number: 2031-67-6
Recommended Uses: Surface treatment of inorganic materials and crosslinker in polymers
Supplier Contact: Refer to manufacturer or distributor contact listed on packaging
Emergency Phone: National chemical emergency centers or poison control
GHS Classification: Flammable Liquid (Category 3), Eye Irritation (Category 2A), Skin Irritation (Category 2)
Label Elements: Signal word ‘Warning’, flame pictogram
Hazard Statements: Causes skin irritation, may cause eye irritation, flammable liquid and vapor
Precautionary Statements: Keep away from sources of ignition, avoid breathing vapors, use protective gloves, wash thoroughly after handling
Potential Health Effects: Irritates skin, eyes and upper respiratory tract, may lead to headaches, dizziness or drowsiness in poorly ventilated areas
Main Component: Methyltriethoxysilane
Chemical Formula: C7H18O3Si
Concentration: ≥99%
Impurities: Trace amounts of ethanol, methanol (often less than 1% total)
Additives: None typically present
Inhalation: Move person to fresh air, seek medical help if symptoms persist; administer oxygen if breathing becomes difficult
Skin Contact: Remove contaminated clothing, wash skin thoroughly with soap and water; seek medical attention if irritation develops or persists
Eye Contact: Flush eyes with plenty of water for at least 15 minutes while lifting the eyelid, remove contact lenses, obtain medical attention
Ingestion: Rinse mouth, do not induce vomiting, drink water if alert; seek immediate medical advice
Immediate Symptoms: Severe irritation, redness, coughing, shortness of breath, headache
Suitable Extinguishing Media: Dry chemical powder, carbon dioxide, alcohol-resistant foam
Unsuitable Media: Direct jets of water can spread fire
Hazardous Combustion Products: Carbon oxides, silicon oxides, possible release of formaldehyde on burning
Special Protective Equipment: Firefighters need full protective clothing and self-contained breathing apparatus
Explosion Hazard: Vapors may form explosive mixtures with air above flash point
Personal Precautions: Remove sources of ignition, ventilate area, use personal protective equipment (gloves, goggles, respirator as needed)
Environmental Precautions: Prevent substance from entering drains, water courses or soil
Spill Cleanup Methods: Contain liquid with inert absorbent (sand, earth, vermiculite), transfer to a labeled waste container for disposal, wash area with water and detergent
Safe Handling Procedures: Use only in well-ventilated areas, avoid skin and eye contact, prevent static discharge, use non-sparking tools
Storage Conditions: Keep containers tightly closed in a cool, dry, well-ventilated place; store away from heat, sparks, and open flames
Incompatible Materials: Strong oxidizers, acids, water/moisture (can lead to slow hydrolysis and release of ethanol)
Exposure Limits: No established US OSHA or ACGIH limits for methyltriethoxysilane; monitor for ethanol/methanol if potential for hydrolysis
Engineering Controls: Use local exhaust ventilation, process enclosures or other engineering controls to maintain airborne levels below exposure limits
Personal Protective Equipment: Chemical-resistant gloves (nitrile or neoprene), safety goggles or face shield, long-sleeved clothing, flame-resistant lab coat
Respiratory Protection: Use respirator approved for organic vapors if ventilation is inadequate
Hygiene Measures: Wash hands before breaks and at end of work; do not eat, drink, or smoke in working area
Appearance: Clear, colorless liquid
Odor: Slight, ethereal
Melting Point: Below -80°C
Boiling Point: 142°C–144°C
Flash Point: 40°C (closed cup)
Vapor Density: 5.9 (air = 1)
Relative Density: 0.89 g/cm³ at 25°C
Solubility: Slightly soluble in water, soluble in organic solvents (alcohols, ethers)
Autoignition Temperature: 230°C
Evaporation Rate: Moderate
Viscosity: Approx. 0.8 mPa·s at 25°C
Chemical Stability: Stable under recommended storage conditions; hydrolyzes slowly in contact with moisture
Hazardous Reactions: Reacts with water to form ethanol and methylsilanetriol; reaction is slow but exothermic
Decomposition Products: Silicon oxides, ethanol, carbon oxides, traces of formaldehyde
Incompatible Materials: Strong oxidizing agents, acids, alkalis, moisture
Possibility of Hazardous Polymerization: Not known to occur
Acute Toxicity: Oral LD50 (rat) approx. 8500 mg/kg; low acute toxicity by inhalation or skin absorption
Skin Corrosion/Irritation: Repeated or prolonged contact can lead to skin drying, cracking, dermatitis
Eye Damage/Irritation: Vapors or direct liquid contact cause eye irritation, tearing, redness
Respiratory Sensitization: May cause irritation of the respiratory tract on high exposure
Chronic Effects: No highly significant chronic toxicity, but repeated exposure increases risk of skin and eye problems
Carcinogenicity: Not classified as carcinogenic by NTP, IARC, or OSHA
Other Information: Hydrolysis releases ethanol, which can contribute to long-term effects if workplace controls slacken
Ecotoxicity: Low acute toxicity to aquatic life, but hydrolysis products (ethanol, silanols) can be harmful at high concentrations
Persistence and Degradability: Degrades in water with slow release of ethanol and silanol compounds
Bioaccumulation Potential: Low; does not accumulate in aquatic or terrestrial food chains
Mobility in Soil: Moderately mobile; silanol byproducts eventually bind to soil minerals
Other Adverse Effects: Avoid uncontrolled release to environment due to possible long-term ecosystem effects from hydrolysis
Waste Treatment Methods: Dispose according to local, regional, national regulations; incineration recommended for hazardous waste
Container Disposal: Empty containers require proper cleaning or professional disposal due to flammability residue
Precautions: Do not pour into drains or natural water sources
Recycling Possibility: Not typically recycled once degraded or mixed with water/moisture
UN Number: 1993
Shipping Name: Flammable liquid, n.o.s. (Methyltriethoxysilane)
Hazard Class: 3 (flammable liquids)
Packing Group: III
Marine Pollutant: Not listed as a marine pollutant
Transport Labels: Flammable liquid symbol required
Special Precautions: Keep containers upright and tightly sealed, away from heat/sources of ignition; notify carrier of hazardous content
Labelling: Classified in accordance with GHS, OSHA Hazard Communication Standard (29 CFR 1910.1200), European CLP Regulation
Inventory Status: Listed in US TSCA, EU REACH, Canada DSL/NDSL, Australia AICS, China IECSC, Japan ENCS
Restrictions: Handle in compliance with all applicable regulations governing flammable chemicals
Other Regulations: Subject to workplace exposure limits for byproducts (ethanol, methanol); environmental emissions to be registered or reported where required
