Chemical Name: Trimethylchlorosilane
CAS Number: 75-77-4
Synonyms: Chlorotrimethylsilane, TMCS
Molecular Formula: C3H9ClSi
Recommended Use: Laboratory reagents, chemical synthesis, surface treatment
Supplier: Company contact details and address provided by distributor
Emergency Telephone: National poison center or local emergency services
Restrictions: Not suitable for food, drug, or household use
GHS Classification: Flammable liquids (Category 2), Skin corrosion/irritation (Category 1B), Eye damage (Category 1), Specific target organ toxicity – single exposure (Category 3)
Signal Word: Danger
Hazard Statements: Highly flammable liquid and vapor, causes severe skin burns and serious eye damage, harmful if inhaled, may cause respiratory irritation
Pictograms: Flame, Corrosive, Exclamation Mark
Precautionary Statements: Keep away from heat/sparks/open flames/hot surfaces, avoid breathing vapors, wear protective gloves/eye protection, IF ON SKIN or ON CLOTHING: take off immediately all contaminated clothing and rinse skin with water, IF INHALED: remove person to fresh air and keep comfortable for breathing, store in a well-ventilated place, keep container tightly closed
Chemical: Trimethylchlorosilane
CAS Number: 75-77-4
Percentage: >99% pure
Impurities: Trace amounts of related silanes, hydrochloric acid vapor possible as decomposition product
Inhalation: Remove person to fresh air, keep warm and at rest, give artificial respiration or oxygen if needed, seek medical attention immediately
Skin Contact: Remove contaminated clothing and rinse skin with plenty of water for at least 15 minutes, call a physician
Eye Contact: Rinse cautiously with water for 15 minutes, lifting upper and lower eyelids occasionally, remove contact lenses if present and easy to do, obtain medical attention immediately
Ingestion: Do not induce vomiting, rinse mouth with water if conscious, seek immediate medical care
Notes for Physician: Treat irritation or burns symptomatically, monitor respiratory function due to risk of delayed pulmonary edema
Suitable Extinguishing Media: Use dry chemical, carbon dioxide, alcohol-resistant foam, do not use water directly on substance
Specific Hazards: Forms flammable vapors heavier than air, may travel to source of ignition, reacts violently with water to release hydrogen chloride gas
Protective Equipment for Firefighters: Use full protective gear including self-contained breathing apparatus, chemical-resistant suit
Fire/Explosion Hazards: Vapor/air mixtures can be explosive, sealed containers exposed to fire may rupture, thermal decomposition yields toxic gases
Personal Precautions: Evacuate area, ventilate and isolate spill leak zone, use personal protective equipment including goggles, gloves, and respirator
Environmental Precautions: Prevent entry into sewers, surface water, or confined areas
Containment/ Cleanup Procedures: Absorb spill with inert material such as dry sand or vermiculite, collect and seal waste in chemical waste containers, neutralize residue with dilute sodium bicarbonate or lime, avoid water contact, ventilate area after cleanup
Safe Handling: Work in chemical fume hood or well-ventilated area, avoid breathing vapors, keep away from sources of ignition, avoid skin and eye contact, do not use near water sources
Storage Conditions: Store in tightly closed containers made of compatible material in a cool, dry, and well-ventilated environment, segregate from moisture, acids, strong oxidizing agents
Special Handling Precautions: Handle under inert atmosphere for bulk storage or long-term opening, ground and bond containers to prevent static discharge, use spark-proof tools and explosion-proof equipment
Exposure Limits: No established OSHA, NIOSH, or ACGIH occupational exposure limits; minimize exposure as low as possible
Engineering Controls: Chemical fume hood required, emergency eye wash and drench shower in work area
Personal Protective Equipment: Impervious gloves (nitrile or butyl recommended), chemical splash goggles, lab coat, flame-retardant antistatic clothing, face shield for large volumes, NIOSH-approved respirator for vapor/mist when ventilation inadequate
Hygiene Measures: Wash hands and face after handling, remove contaminated clothing and wash before reuse
Appearance: Clear, colorless liquid
Odor: Sharp, irritating, acid-like at high concentrations
Boiling Point: 57–58°C
Melting Point: –57°C
Flash Point: –6°C (closed cup)
Vapor Pressure: 220 mmHg at 20°C
Vapor Density: 4.5 (air = 1)
Solubility in Water: Reacts violently, hydrolyzes to trimethylsilanol and HCl
Density: 0.855 g/cm³ at 20°C
Partition Coefficient: log Kow ~1.9
Autoignition Temperature: 320°C
Viscosity: ~0.5 mPa·s at 25°C
Evaporation Rate: Rapid, but reacts with moisture in air
Chemical Stability: Stable under recommended storage conditions in absence of moisture
Incompatible Materials: Water, humid air, strong oxidizers, strong bases, strong acids, alcohols, ammonia
Hazardous Decomposition Products: Hydrogen chloride gas, siloxanes, flammable gases
Possibility of Hazardous Reactions: Violent hydrolysis reaction with water yields heat and corrosive hydrogen chloride, may contain pressure from generation of gases in sealed containers
Conditions to Avoid: Moist or humid environments, open flames, static electricity, direct sunlight
Routes of Exposure: Inhalation, ingestion, skin and eye contact
Acute Toxicity: Oral LD50 (rat): 2080 mg/kg; Inhalation LC50 (rat): 45 mg/L/4h
Skin Corrosion/Irritation: Causes severe burns, scarring possible
Eye Damage/Irritation: Severe irritation to eye tissue, can result in permanent eye injury or blindness
Respiratory Sensitization: Vapors cause coughing, burning, dyspnea, pulmonary edema possible
Chronic Effects: Repeated skin contact causes dryness and dermatitis, prolonged or repeated exposure irritates respiratory tract
Carcinogenicity: Not considered carcinogenic by NTP, IARC, OSHA
Other: Decomposes to form hydrochloric acid which can aggravate lungs, eyes, skin
Ecotoxicity: Toxic to aquatic organisms by acute exposure due to pH changes, hydrolysis products degrade quickly in environment
Persistence and Degradability: Hydrolyzes rapidly in water, forms silanols and hydrochloric acid, not considered persistent
Bioaccumulation: Low potential due to hydrolysis and reactivity
Mobility in Soil: Hydrolysis products are mobile, parent compound unlikely to reach groundwater when properly handled
Other Adverse Effects: Not expected to contribute significantly to ozone depletion, photochemical smog, or global warming, care needed to contain spills
Waste Disposal Methods: Consult federal, state, and local regulations, destroy by incineration in chemical incinerator equipped with afterburner and scrubber
Handling of Contaminated Packaging: Triple rinse containers, puncture and dispose of in approved landfill or incineration facility, label as hazardous waste
Precautions: Do not release to environment, neutralize residue before disposal
UN Number: UN 1298
Proper Shipping Name: Trimethylchlorosilane
Transport Hazard Class: 3 (Flammable liquid)
Packing Group: I
Hazard Labels: Flammable Liquid, Corrosive
Marine Pollutant: No
Special Precautions: Secure bottles in upright position, use non-sparking tools, keep away from heat and moisture during transport, emergency response guidebook code 127
US TSCA: Listed
DSL/NDSL (Canada): Listed
EINECS (Europe): 200-900-5
OSHA Hazards: Flammable liquid, skin corrosive, respiratory hazard
SARA Title III: Not subject to reporting, but contains a hazardous chemical
California Proposition 65: Not listed as a carcinogen or reproductive toxin
REACH (EU): Registration required for import or production above 1 ton/year
Other: Compliance with all state, federal, and local regulations required, reportable quantity under CERCLA not defined, observe national and international chemical safety codes
