Product Name: N-Propyltrimethoxysilane
Chemical Formula: C6H16O3Si
Synonyms: Trimethoxy-n-propylsilane
CAS Number: 1067-25-0
Manufacturer Contact: Emergency phone numbers and supplier addresses should appear on the container label and incoming shipping documents for quick reference. Users dealing with large volumes or industrial processes often need to keep a direct line posted for chemical incidents.
Recommended Use: Often added to industrial materials as a coupling agent to boost adhesion between organic polymers and inorganic surfaces. Uses in sealants, adhesives, and coatings reflect its widespread role in construction and electronics.
Classification: Flammable liquid, Category 3; Eye irritation, Category 2
Signal Word: Warning
Pictograms: Flame, Exclamation mark
Hazard Statements: Flammable liquid and vapor. Causes serious eye irritation. May cause skin and respiratory tract irritation on contact or inhalation.
Precautionary Statements: Keep away from heat/sparks/open flames/hot surfaces. Use only outdoors or in well-ventilated area. Wear protective gloves and eye/face protection. In case of fire, use dry chemical or carbon dioxide to extinguish.
Routes of Exposure: Eyes, skin, inhalation, ingestion-all routes require attention if exposure occurs.
Chemical Name: N-Propyltrimethoxysilane
Concentration: >98%
Chemical Formula: C6H16O3Si
CAS Number: 1067-25-0
Impurities: Possible trace methanol, which can increase health risks, especially in processes involving heat.
Inhalation: Move to fresh air and keep comfortable for breathing. If symptoms persist, seek medical help quickly. It’s common for workers to underestimate the severity of fumes until irritation sets in-early action helps recovery.
Skin Contact: Remove contaminated clothing and wash exposed skin immediately with soap and water. Chemical burns need prompt medical attention.
Eye Contact: Rinse cautiously with water for several minutes, removing contact lenses if safe to do so. Persistent pain requires professional evaluation.
Ingestion: Rinse mouth. Don’t induce vomiting. Get medical help if feeling unwell.
General Advice: Always get medical attention if unsure about exposure or symptoms.
Suitable Extinguishing Media: Dry chemical, CO2, foam, or water spray can tackle fires involving this product. Avoid high-pressure water jets, as they can spread burning liquid.
Specific Hazards: Vapors may form explosive mixtures with air. Heating leads to decomposition and release of toxic fumes like silicon oxides and methanol, which brings another layer of risk.
Special Protective Equipment: Firefighters need self-contained breathing apparatus and chemical protective gear. Water runoff should not be allowed into drains.
Advice: Always fight chemical fires from a safe distance, using caution to prevent inhalation of combustion products.
Personal Precautions: Remove all ignition sources. Ventilate area and wear chemical-resistant gloves, goggles, and suitable respirator if a large spill occurs.
Environmental Precautions: Prevent run-off into sewers and waterways. Diking with sand or soil can help contain liquid spills.
Cleanup Methods: Absorb with inert material like vermiculite or sand, scoop into sealed containers, and label for proper hazardous waste disposal.
Advice for Clean-Up Crews: Avoid breathing vapor and contact with skin or eyes during cleaning. Regular training in spill response makes all the difference in limiting exposure.
Handling: Use spark-proof tools and explosion-proof equipment. Local exhaust ventilation often becomes essential in enclosed workspaces. Avoid contact with eyes, skin, and clothing. Wash hands after handling.
Storage: Store in original tightly closed container in a cool, dry, and well-ventilated location away from sources of ignition and incompatible materials like strong acids, oxidizing agents, and water.
Recommended Storage Conditions: Storage at low temperatures reduces vapor build-up and extends shelf life. Use corrosion-resistant containers.
Engineering Controls: Implement local exhaust ventilation and spark-proof fans. Automated transfer and mixing systems further reduce risk.
Personal Protective Equipment (PPE): Chemical splash goggles, flame-resistant gloves, lab coat or overall, and flame-resistant shoes. Respiratory protection often needed, especially in areas without strong ventilation.
Exposure Limits: No established OSHA or ACGIH exposure limits for N-Propyltrimethoxysilane itself, though exposure to generated methanol should not exceed legal limits (200 ppm TWA in the US).
Hygiene Measures: Wash thoroughly after handling. Remove contaminated clothing and equipment before entering eating areas.
Appearance: Colorless liquid with a slight characteristic odor
Odor Threshold: Not determined; odor is not a reliable leak indicator.
pH: Not applicable
Melting Point/Freezing Point: Below -60°C
Boiling Point: 142°C
Flash Point: 34°C (closed cup)
Evaporation Rate: No reliable data published
Flammability: Liquid and vapor are flammable. Catches fire easily near ignition sources.
Upper/Lower Flammability Limits: Not determined
Vapor Pressure: 2 mmHg at 20°C
Vapor Density (Air = 1): About 5.5
Relative Density: ~0.95 g/cm³ at 20°C
Solubility: Hydrolyzes in water; soluble in most organic solvents.
Partition Coefficient (n-octanol/water): No data
Auto-ignition Temperature: Not established
Decomposition Temperature: Not available
Chemical Stability: Stable under recommended handling and storage conditions.
Reactivity: Reacts with water and moisture to form methanol and silanols, releasing heat and possibly hazardous vapors.
Hazardous Reactions: Avoid contact with acids, oxidizers, and bases; such reactions increase fire and toxicity risks.
Hazardous Decomposition Products: Methanol, formaldehyde, silicon oxides can evolve during combustion or hydrolysis.
Conditions to Avoid: Exposure to flames, static discharge, or storing in humid or wet environments accelerates breakdown and increases hazards.
Routes of Exposure: Inhalation, skin, eyes, ingestion
Acute Effects: Causes moderate to severe irritation of eyes and respiratory tract. Skin contact may cause mild redness or dryness after prolonged exposure. Inhaling high levels of vapor sometimes triggers headache, drowsiness, or dizziness.
Chronic Effects: Regular exposure to hydrolysis byproducts such as methanol can build up over time and harm vision or central nervous function. Skin sensitization rarely reported but should not be ruled out.
Toxicity Data: Oral LD50 (rat): >2000 mg/kg; Dermal LD50 (rabbit): >2000 mg/kg. Methanol byproduct carries systemic toxicity risk.
Symptoms of Overexposure: Burning of eyes and throat, coughing, headache, nausea.
Ecotoxicity: Hydrolysis yields methanol, which is toxic to aquatic organisms. Direct spills into water may harm fish, daphnia, or algae.
Persistence and Degradability: Reacts quickly with moisture, breaking down to less persistent silanols. Methanol dissipates rapidly, but acute toxicity still presents a hazard during accidental release.
Bioaccumulation Potential: No significant accumulation expected for silanes; methanol has low bioaccumulation risk.
Mobility in Soil: High; both liquid and volatile forms travel through soil and vaporize to some extent, leading to groundwater contamination if uncontrolled.
Other Adverse Effects: Avoid release to the environment.
Waste Disposal: Treat as hazardous chemical waste at licensed facility. Seek guidance from local, regional, or national regulations before disposal. Absorbed waste from spill clean-ups also needs to go into proper containers and labels.
Other Disposal Recommendations: Incineration under controlled conditions, with proper emission treatment, greatly reduces environmental burden.
Empty Containers: Triple-rinse, puncture, and recycle or dispose according to hazardous waste guidelines. Containers often retain vapor and residue after use.
UN Number: UN1993
Proper Shipping Name: Flammable Liquid, N.O.S. (contains Propyltrimethoxysilane)
Transport Hazard Class: 3 (Flammable liquid)
Packing Group: III
Labels: Flammable liquid pictogram
Special Precautions for User: Secure upright during transit, store away from foodstuffs and oxidizing agents. Drum grounding and bonding eliminate static electricity risks.
Marine Pollutant: Not classified as marine pollutant, but methanol formation on water contact is an extra hazard.
TSCA (USA): Listed
REACH (EU): Registered
OSHA Hazard Communication Standard: Classified as hazardous
EPCRA Section 313: Methanol generated as a breakdown product is listed
WHMIS (Canada): B2 (Flammable Liquid), D2B (Toxic Material)
SARA 311/312: Fire hazard, acute health hazard
Other National Regulations: Users must check with country-specific chemical safety and worker protection agencies for further requirements.
