Product Name: N-Octadecylmethyldichlorosilane
Synonyms: Octadecylmethyldichlorosilane, ODMDS
Chemical Formula: C19H40Cl2Si
CAS Number: 1996-39-4
Recommended Use: Used in surface treatment, coatings, research laboratories
Manufacturer/Supplier: Contact information of supply company required on procurement; commonly distributed by specialty chemical vendors
Emergency Phone: Refer to supplier-specific emergency numbers; many rely on local poison control or Chemtrec
GHS Classification: Skin Corrosion/Irritation - Category 1B, Serious Eye Damage/Irritation - Category 1, Acute Toxicity (Oral, Inhalation, Dermal) - Category 4
Label Elements: Signal Word: Danger; Pictograms: Corrosive, Exclamation Mark
Hazard Statements: Causes severe skin burns and eye damage. Harmful if inhaled, swallowed, or absorbed through skin.
Precautionary Statements: Avoid breathing dust, fume, gas, mist, vapors, spray. Wear protective gloves, clothing, eye and face protection. Use only outdoors or in a well-ventilated area.
Potential Health Effects: Physical contact burns skin, eyes. Fumes cause irritation to respiratory tract. Ingestion causes symptoms from sore throat to severe abdominal pain.
Chemical Name: N-Octadecylmethyldichlorosilane
Common Name/Synonyms: ODMDS, Octadecylmethyldichlorosilane
CAS Number: 1996-39-4
Concentration: 100% pure unless diluted; industrial and research grades may vary slightly
Molecular Weight: 367.5 g/mol
Impurities/Additives: Lesser silanes, moisture trace possible; typical material meets >98% purity for laboratories
Inhalation: Remove individual to fresh air, ensure breathing unimpeded, give oxygen if needed. Medical attention if symptoms persist.
Skin Contact: Remove contaminated clothing, rinse skin with plenty of water for at least 15 minutes. Seek immediate medical attention.
Eye Contact: Rinse eyes cautiously with water for at least 15 minutes, lifting eyelids. Contact physician immediately.
Ingestion: Rinse mouth with water, do not induce vomiting. Immediate medical assistance critical. Chemical burns possible.
Most Important Symptoms: Severe irritation, burns, difficulty breathing, vision impairment
Advice for First Responders: Ensure self-protection, use appropriate PPE, avoid contaminated area vapor
Suitable Extinguishing Media: Use dry chemical powder, foam, or CO2. Avoid water; reacts with water liberating hydrogen chloride gas.
Specific Hazards: Fires produce toxic gases: HCl, silicon oxides, carbon oxides. Reacts with water, moisture generates corrosive vapors.
Protective Equipment for Firefighters: Full-body chemical suit, self-contained breathing apparatus required.
Firefighting Procedures: Stay upwind, keep containers cool with shielding agents. Control runoff—prevent environmental contamination.
Personal Precautions: Evacuate area, ensure proper ventilation. Wear full chemical-resistant suit, gloves, goggles, and respiratory protection.
Environmental Precautions: Prevent spills from entering drains, soil, water bodies. Use containment systems where possible.
Methods for Cleaning Up: Use inert absorbent materials such as sand, diatomaceous earth. Collect residue in closed, labeled containers for disposal. Ventilate the affected area. Decontaminate with alcohol or dilute caustic solution, following strict protocols.
Handling: Use in chemical fume hood, wear protective gear, minimize aerosol or mist generation. Take measures against electrostatic charge. Prevent contact with water and moisture.
Storage: Store in tightly sealed containers, away from moisture, acids, alcohols. Store below 25°C in a cool, dry place. Keep away from food and incompatible materials. Maintain appropriate signage and safety labeling near storage area.
Incompatibilities: Strong oxidizers, strong bases, acids, water, alcohols. Contact with any moist air causes hazardous decomposition.
Engineering Controls: Chemical fume hood, local exhaust ventilation recommended. Eye-wash stations and emergency showers should be nearby.
Personal Protective Equipment: Chemical-resistant gloves (nitrile, neoprene), full face shield, tight-fitting safety goggles, laboratory coat/apron with acid-resistant properties, long sleeves, chemical-resistant footwear, if handling large amounts.
Respiratory Protection: Appropriate air-purifying or supplied-air respirator if airborne concentration exceeds limits or during accidental release.
Hygiene Measures: Wash hands thoroughly after use, avoid eating, drinking, or smoking when handling. Remove contaminated clothing before breaks or leaving laboratory.
Occupational Exposure Limits: No established OSHA or ACGIH exposure limits for pure ODMDS; analogous limit guidance from similar dichlorosilanes may apply.
Appearance: Colorless to pale yellow liquid
Odor: Sharp, acrid, pungent odor
Boiling Point: 374°C (705°F)
Melting Point: -1°C (30°F)
Flash Point: Above 170°C (closed cup)
Flammability: Not easily ignited but produces flammable vapors in specific conditions
Vapor Pressure: Low at room temperature
Density: About 0.86 g/cm³ at 25°C
Solubility: Insoluble in water; reacts violently generating hydrogen chloride
Partition Coefficient (log Kow): Not available, but expected high
Viscosity: Slightly viscous at standard temperature
Chemical Stability: Stable under dry, recommended storage conditions. Hydrolyzes readily in presence of water or humidity.
Reactivity: Reactive toward water, alcohols, bases, acids; produces hydrogen chloride, heat.
Incompatible Materials: Water, aqueous solutions, strong acids, bases, strong oxidizers, alcohols, amines.
Hazardous Decomposition Products: Hydrogen chloride, silicon oxides, hydrocarbons.
Polymerization: No dangerous polymerization known under normal handling
Likely Routes of Exposure: Inhalation, skin and eye contact, ingestion
Acute Toxicity (Values): Oral rat LD50 ~1500 mg/kg; inhalation rat LC50 (4h) not fully established; skin and eye severe irritation/corrosion documented
Skin Corrosion/Irritation: Causes severe chemical burns, blistering
Serious Eye Damage/Irritation: Results in blindness or permanent injury possible
Inhalation Effects: Respiratory tract irritation, coughing, choking, risk of pulmonary edema from prolonged exposure
Sensitization: No strong evidence for skin or respiratory sensitization from available studies
Chronic Effects: Chronic skin or lung exposure may cause lasting damage and increased cancer risk not proven in animal models
Other Information: Rapid medical attention vital in all accidental exposures; delayed symptoms occur
Ecotoxicity: Material expected to be toxic to aquatic organisms, risk of long-term adverse effects in aquatic environment.
Persistence and Degradability: Hydrolyzes rapidly, forming persistent organosilicon compounds and hydrochloric acid.
Bioaccumulation Potential: High hydrophobicity suggests potential for bioaccumulation in aquatic species.
Mobility in Soil: Low mobility due to strong adsorption to organic matter; hydrolysis products mobile depending on conditions.
Other Adverse Effects: Spilled quantities degrade into hazardous residues. Reduce contamination risk by strict containment.
Waste Treatment Methods: Dispose as hazardous waste per local, state, national regulations. Do not allow into sewers or water bodies.
Product Disposal: Chemical incineration in compliance with government regulations; do not landfill untreated.
Contaminated Packaging: Decontaminate before recycling/disposal; triple rinse, puncture, label as hazardous.
Special Precautions: Neutralize hydrolysis byproducts with sodium bicarbonate or similar alkalizing agents before final treatment if possible.
UN Number: 1760
Proper Shipping Name: Corrosive Liquid, n.o.s. (contains N-Octadecylmethyldichlorosilane)
Transport Hazard Class: 8 (Corrosive substances)
Packing Group: II
Environmental Hazards: Marine pollutant; mark accordingly for sea transport
Special Precautions: Use UN-approved containers, ensure trained handlers transport under strict documentation. Emergency spill response kit necessary.
Regulatory References: IATA, IMDG, DOT numbers match above profile; specific codes checked before shipment
OSHA: Regulated as hazardous. Label according to hazard communication standard.
TSCA: Listed on US Toxic Substances Control Act inventory.
EINECS/ELINCS: Listed in European chemicals inventory.
REACH: Pre-registered or registered under specific uses. Importers in Europe must consult supplier for compliance.
SARA Title III: Not listed as an extremely hazardous or reportable substance but included due to acute hazards.
California Prop 65: No direct listing. Consult latest regulatory status on reproductive toxicity and cancer agent inclusions.
Other Requirements: Labor codes in several countries mandate comprehensive training for handlers and responders; consult national and regional guidelines for workplace safety, emissions, and environmental release controls.
