Product Name: Octamethylcyclotetrasiloxane
Chemical Formula: C8H24O4Si4
Synonyms: D4
CAS Number: 556-67-2
Recommended Use: Silicone polymer manufacturing, antifoaming agent, personal care product formulation
Supplier: Manufacturer or distributor company name and contact details
Emergency Contact: Local emergency telephone information
GHS Classification: Flammable Liquids (Category 4), Eye Irritation (Category 2B), Reproductive Toxicity (Category 2), Specific Target Organ Toxicity - Single Exposure (Category 3)
Signal Word: Warning
Hazard Statements: Causes eye irritation, suspected of damaging fertility, may cause respiratory irritation, combustible liquid
Pictograms: Exclamation mark, health hazard, flame
Precautionary Statements: Avoid contact with eyes, avoid inhalation of vapors, keep away from fires and hot surfaces, use only outdoors or in well-ventilated areas, wear protective gloves and eye protection
Chemical Name: Octamethylcyclotetrasiloxane
Common Name: D4
Concentration: >99%
CAS Number: 556-67-2
Other Components: No other relevant components present at concentrations required for disclosure
Inhalation: Remove to fresh air, keep individual comfortable, seek medical attention if symptoms develop
Skin Contact: Wash affected area thoroughly with soap and water, remove contaminated clothing, consult physician if irritation occurs
Eye Contact: Rinse cautiously with water for several minutes, remove contact lenses if present and easy, continue rinsing, seek medical advice if discomfort persists
Ingestion: Rinse mouth, do not induce vomiting, seek immediate medical attention
Suitable Extinguishing Media: Dry chemical powder, foam, carbon dioxide, water spray (to cool adjacent containers)
Specific Hazards: Combustible liquid, produces irritating fumes and silicon oxides during combustion
Fire-Fighter Precautions: Wear self-contained breathing apparatus and full protective gear, avoid inhaling combustion products
Explosion Sensitivity: Vapors may form explosive mixtures with air under certain conditions, especially in confined spaces
Personal Precautions: Evacuate unnecessary personnel, ventilate area, wear suitable protective equipment (gloves, goggles, respirator)
Environmental Precautions: Prevent further leakage or spillage if safe to do so, avert contamination of water sources and drains
Clean-up Methods: Absorb with inert material such as sand or earth, sweep up, collect in suitable containers for disposal, wash area with plenty of water
Handling: Use only in areas with good ventilation, avoid inhalation of vapor and contact with eyes and skin, keep away from open flames, hot surfaces, and static discharge, transfer using grounded and bonded equipment
Storage: Store in tightly closed original containers, keep in cool, dry, well-ventilated area away from incompatible materials such as strong oxidizers, avoid storage at elevated temperatures or in direct sunlight, segregate from food and feedstuffs
Engineering Controls: Provide mechanical ventilation or local exhaust to keep airborne concentrations below recommended limits
Exposure Limit Values: Workplace Environmental Exposure Level (WEEL): 10 ppm (inhalation), TWA
Personal Protection: Chemical-resistant gloves, safety goggles or full face shield, long-sleeved clothing, certified respirator for organic vapor if airborne concentrations are high
Hygiene Measures: Wash hands thoroughly after use, no eating, drinking, or smoking in work area, change contaminated clothing immediately
Appearance: Clear, colorless liquid
Odor: Mild, characteristic silicone odor
Odor Threshold: Not determined
pH: Not applicable
Melting Point/Freezing Point: 17.8°C
Boiling Point: 175°C at 1013 hPa
Flash Point: 75°C (closed cup)
Evaporation Rate: Not determined
Flammability: Combustible
Upper/Lower Flammability Limits: 0.6% (lower), 2.6% (upper, v/v, air)
Vapor Pressure: 1.5 hPa at 25°C
Vapor Density: 6.0 (air=1)
Relative Density: 0.96 (water = 1)
Solubility: Insoluble in water, miscible with organic solvents
Partition Coefficient (n-octanol/water): 6.49
Autoignition Temperature: 290°C
Decomposition Temperature: No data available
Viscosity: 2.4 mm2/s at 25°C
Chemical Stability: Stable under recommended storage conditions, remains intact in normal temperatures and pressures
Hazardous Reactions: No dangerous reaction known under normal use, vapors may form explosive mixture with air under certain conditions
Conditions to Avoid: Avoid heat, flames, sparks, static charge, prolonged exposure to air
Incompatible Materials: Strong oxidizing agents, acids, strong bases, halogens
Hazardous Decomposition Products: Silicon oxides, formaldehyde, methanol, various organic compounds generated during combustion
Acute Toxicity: Oral LD50 (rat): > 4800 mg/kg, Inhalation LC50 (rat, 4 hr): > 36 mg/L, Dermal LD50 (rabbit): > 2400 mg/kg
Skin Corrosion/Irritation: Mild skin irritation possible
Serious Eye Damage/Irritation: Causes temporary eye irritation
Respiratory or Skin Sensitization: Not classified as a sensitizer
Germ Cell Mutagenicity: Not classified
Carcinogenicity: Not classified as a human carcinogen
Reproductive Toxicity: Suspected of causing reproductive and developmental toxicity (based on animal studies, EU classification)
Specific Target Organ Toxicity: May cause respiratory irritation
Other Effects: Headache, dizziness, vomiting at high vapour concentrations
Ecotoxicity: Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment
Persistence and Degradability: Not readily biodegradable, persistent in environment
Bioaccumulative Potential: High potential for bioaccumulation (log Kow > 6)
Mobility in Soil: Low mobility, strongly adsorbed to soil particles
Other Adverse Effects: Siloxanes such as D4 detected in surface waters and sediments, concerns of accumulation in living organisms and possible endocrine disruption in aquatic life
Disposal Methods: Dispose in accordance with local, regional, and national regulations, incinerate in suitable facility where permitted, do not release into sewers or environment
Container Disposal: Empty containers retain product residue, dispose of as hazardous waste, do not reuse container
Waste Code: Assign proper waste code based on regulatory requirements in country of use
UN Number: 2290
UN Proper Shipping Name: Octamethylcyclotetrasiloxane
Transport Hazard Class: 9 (Miscellaneous dangerous substances)
Packing Group: III
Labels Required: Environmentally hazardous substance, misc. hazard
Marine Pollutant: Yes
Special Precautions for Users: Avoid release to environment during transport, secure packaging to prevent leaks or spills
TSCA (US): Listed
EINECS (EU): 209-136-7
REACH Registration: Registered, subject to restrictions for consumer use in EU
OSHA (US): Hazardous chemical, workplace controls required
Canada WHMIS: Classified as hazardous
SARA Title III (US): Not listed as an extremely hazardous substance
California Prop 65: Not listed
Other International Inventories: Listed on Australia AICS, Japan ENCS, China IECSC
Restriction Notes: Use and sale restricted in specific jurisdictions due to environmental concerns (notably EU, Canada)
