Product Name: Hexamethyldisilazane
Synonyms: HMDS, 1,1,1,3,3,3-Hexamethyldisilazane
Chemical Formula: C6H19NSi2
CAS Number: 999-97-3
Manufacturer: Refer to supplier label
Recommended Use: Silylation agent in chemical processing, electronics, lab reagent
Emergency Contact: Manufacturer emergency phone number provided on label
Classification: Flammable liquid, Acute toxicity (oral, inhalation, dermal), Skin and eye irritant
Signal Word: Danger
Hazard Statements: Highly flammable liquid and vapor, harmful if inhaled or ingested, causes skin and serious eye irritation, may cause respiratory discomfort
Pictograms: Flame, health hazard, exclamation mark
Precautionary Statements: Keep away from heat, sparks, open flames; avoid breathing vapors; wear protective gloves and eye protection; use only outdoors or in a well-ventilated area; keep container tightly closed
Chemical Name: Hexamethyldisilazane
Concentration (w/w): ≥99%
Impurities: Trimethylsilanol, trimethylchlorosilane (trace)
Stabilizing Additives: None listed in most pure formulations
Inhalation: Move person to fresh air, monitor for breathing difficulty, seek medical attention if symptoms develop
Skin Contact: Remove contaminated clothing, wash affected skin with soap and water, seek medical help if irritation lasts
Eye Contact: Rinse with plenty of water for several minutes, remove contact lenses if present, get medical attention if irritation persists
Ingestion: Rinse mouth with water, do not induce vomiting, seek immediate medical aid
Most Important Symptoms: Cough, sore throat, dizziness, redness, pain, blurred vision, abdominal pain in case of ingestion
Suitable Extinguishing Media: Dry chemical, foam, carbon dioxide, do not use water jet
Special Hazards: Vapors may form explosive mixtures with air, releases toxic gases like ammonia and oxides of nitrogen/silicon during combustion
Protective Equipment: Firefighters wear self-contained breathing apparatus, chemical protective clothing
Firefighting Procedures: Evacuate area, use water spray for cooling exposed containers, avoid breathing fumes, stay upwind of spill
Personal Precautions: Evacuate unnecessary personnel, ventilate area, use personal protective equipment (gloves, goggles, respirators)
Environmental Precautions: Prevent entry into drains, waterways, soil
Methods for Cleanup: Contain and absorb spill with inert materials like sand or vermiculate, collect into labeled sealable containers, dispose according to local regulations
Other Information: Remove all ignition sources near spill
Handling: Use in well-ventilated areas, avoid inhalation or skin contact, ground all equipment, avoid static discharge, do not eat or drink while working with material
Storage: Store in tightly closed containers, keep away from heat, sparks, flame, incompatible substances such as water, acids, and oxidizers, maintain in a cool, dry ventilated space, segregate from foods and incompatible chemicals
Exposure Limits: No established OSHA or ACGIH exposure limits for HMDS, monitor for ammonia in air as an indicator
Engineering Controls: Local exhaust ventilation, fume hood recommended
Personal Protection: Chemical-resistant gloves (nitrile or butyl), splash-proof safety goggles, flame-resistant lab coat, properly fitted respirator if vapor concentration is high
Hygienic Practices: Wash hands before breaks and after handling, do not smoke near product, dispose of contaminated clothing appropriately
Physical State: Colorless liquid
Odor: Ammonia-like, sharp
Melting Point: -57°C (-70.6°F)
Boiling Point: 125°C (257°F)
Flash Point: 18°C (64°F), closed cup
Vapor Pressure: 20 mmHg (25°C)
Vapor Density: 5.6 (air = 1)
Solubility: Reacts with water, soluble in organic solvents
Autoignition Temperature: 240°C (464°F)
Specific Gravity: 0.77 (water = 1)
Evaporation Rate: Not available
Stability: Stable under recommended storage and handling conditions
Reactivity: Reacts violently with acids, oxidizing agents, water, alcohols to produce toxic gases
Hazardous Decomposition: Ammonia, silicon oxides, nitrogen oxides
Polymerization: Product does not polymerize under normal use
Incompatible Materials: Water, acids, halogens, oxidizers, strong bases, alcohols
Acute Toxicity: LD50 oral (rat) around 850 mg/kg; inhalation and dermal toxicity data limited
Routes of Exposure: Inhalation, skin absorption, eye contact, ingestion
Symptoms: Irritation of respiratory system, eyes, skin; dizziness; headache; gastrointestinal upset if ingested
Chronic Effects: No reliable data on long-term or chronic exposure impacts
Carcinogenicity: No data showing carcinogenic potential in humans
Mutagenicity: Not listed as mutagenic
Sensitization: Has not been shown to cause allergic reactions in animals or humans
Aquatic Toxicity: Toxic to aquatic organisms based on similar organosilicon compounds
Persistence and Degradability: Decomposes in water to silanols and ammonia
Bioaccumulative Potential: Low expected, hydrolyzes rapidly
Mobility: Volatile, likely to evaporate from soil surfaces, hydrolysis limits soil leaching
Other Adverse Effects: Ammonia produced from hydrolysis may contribute to eutrophication and aquatic toxicity
Methods of Disposal: Burn in a chemical incinerator equipped with afterburner and scrubber; separate disposal for contaminated absorbents
Contaminated Packaging: Empty containers retain product vapors and residues; handle as hazardous waste
Waste Code: Relevant local hazardous waste code, usually EPA hazardous waste U-listed for solvents
Precautions: Do not discharge to sewer, surface water, or soil
UN Number: UN 1993
Proper Shipping Name: Flammable Liquid, N.O.S. (Hexamethyldisilazane)
Transport Hazard Class: 3 (Flammable liquids)
Packing Group: II
Shipping Label: Flammable Liquid
Additional Info: Keep away from oxidizers and foodstuffs in transit, ensure containers are firmly secured and upright
US Regulations: Listed on TSCA inventory, SARA 313 not listed, subject to OSHA Hazard Communication
EU Regulations: Listed in EINECS/ELINCS, classified under CLP as flammable and health hazard
Hazard Classifications: Acute Toxicity, Flammable Liquid, Eye and Skin Irritant
Other Global: Complies with GHS labeling, regulations vary by country
Worker Protection: Training required regarding hazards, PPE, safe handling, and disposal, safety data sheet must be accessible at workplace
