Material Safety Data Sheet: Tungsten Disulfide

Identification

Product Name: Tungsten Disulfide
Chemical Formula: WS₂
CAS Number: 12138-09-9
Relevant Identified Uses: Lubricant, additive for coatings and plastics, research applications
Supplier: Name, address, emergency contact number required
Recommended Restrictions: Industrial use only, not for ingestion or medical purposes

Hazard Identification

Classification: Not classified as hazardous under GHS guidelines
Physical Hazards: Inhalation of fine dust could cause respiratory irritation
Health Hazards: Dust can irritate eyes, nose, throat; chronic exposure has not shown documented severe effects in humans
Environmental Hazards: Large spills in aquatic areas could disrupt local organisms
Label Elements: Not considered hazardous, but use with caution to prevent airborne dust
Precautionary Statements: Avoid dust generation, minimize direct skin and eye contact

Composition / Information on Ingredients

Chemical: Tungsten Disulfide
Synonyms: Tungsten(IV) sulfide, WS₂
CAS No: 12138-09-9
Purity: Over 98% by weight typical
Impurities: Trace amounts of tungsten oxides, sulfur, or metal contaminants may be present based on source

First Aid Measures

Inhalation: Move to fresh air; seek medical help if coughing, shortness of breath, or symptoms persist
Skin Contact: Wash with soap and water; remove contaminated clothing; if irritation develops, get medical attention
Eye Contact: Rinse cautiously with water for several minutes; remove contact lenses; consult a physician if discomfort continues
Ingestion: Rinse mouth; do not induce vomiting; drink water; seek medical direction if feeling unwell
Important Symptoms: Dust may cause irritation to mucous membranes and airways; persistent effects require professional care

Fire-Fighting Measures

Suitable Extinguishing Media: Carbon dioxide, dry chemical, foam; use water spray to cool containers
Unsuitable Media: Avoid strong water jets that might spread powder
Hazardous Combustion Products: May release tungsten oxides and sulfur dioxide fumes if involved in fire
Protective Equipment: Firefighters need self-contained breathing apparatus, full protective suit for metal fires
Fire Hazards: Product does not burn easily, but powder clouds may catch fire in rare extreme conditions

Accidental Release Measures

Personal Precautions: Wear approved respirator, safety goggles, and gloves; avoid creating dust
Environmental Precautions: Prevent contamination of water sources and sewer systems
Spill Cleanup: Use damp methods or HEPA vacuum for dust; do not sweep dry; collect in suitable containers for disposal
Reporting: Large or hazardous releases to be reported according to national regulations

Handling and Storage

Safe Handling: Avoid breathing dust, minimize dust formation, work in well-ventilated area, use appropriate personal protective equipment
Storage Conditions: Store in tightly closed container, keep dry, avoid humidity, store away from incompatible materials such as strong oxidizers
Specific Uses: Follow recommended application instructions; avoid any process generating airborne WS₂ dust

Exposure Controls and Personal Protection

Exposure Limits: No established OSHA or ACGIH limits for tungsten disulfide; general dust exposure limits apply (total dust: 15 mg/m³, respirable: 5 mg/m³)
Engineering Controls: Use local exhaust ventilation, process enclosures, or other engineering controls to limit airborne concentrations
Personal Protective Equipment: Safety glasses with side shields, gloves made from chemical-resistant material, NIOSH-approved respirator if exposure exceeds guidelines
Hygiene Measures: Do not eat, drink, or smoke while handling; wash hands thoroughly after use

Physical and Chemical Properties

Appearance: Fine gray to black powder
Odor: Odorless
Odor Threshold: Not applicable
pH: Not applicable
Melting Point: 1,250°C (2,282°F)
Boiling Point: Approximately 2,250°C (4,082°F) at 760 mmHg
Relative Density: About 7.5 g/cm³
Solubility: Insoluble in water
Vapor Density: Not applicable
Flash Point: Not flammable
Partition Coefficient: Not determined
Decomposition Temperature: Above 1,250°C (release of SO₂)
Molecular Weight: 247.97 g/mol
Evaporation Rate: Not applicable

Stability and Reactivity

Chemical Stability: Stable at ambient temperatures under normal storage and handling
Reactive Hazards: Stable under recommended use; may react with strong acids to release hydrogen sulfide
Conditions to Avoid: Excessive moisture, strong oxidizing agents, strong acids
Incompatible Materials: Chlorine trifluoride, fluorine, strong acids and oxidizers
Hazardous Decomposition: Sulfur dioxide, tungsten oxides under extreme heat or fire

Toxicological Information

Likely Routes of Exposure: Inhalation, skin contact, eye contact
Acute Toxicity: No acute toxicity found in available literature; mechanical irritation possible
Chronic Toxicity: Long-term health effects not well studied; repeated exposure to high dust levels can irritate lungs
Carcinogenicity: Not listed by IARC, NTP, or OSHA as a carcinogen
Sensitization: No data to suggest allergic reactions
Specific Target Organ Toxicity: None identified at occupational exposure levels
Other Information: Practicing good hygiene and exposure minimization reduces risks

Ecological Information

Ecotoxicity: Not particularly toxic to aquatic organisms in low concentrations; large spills pose risk of sedimentation and physical impact
Persistence and Biodegradability: Does not break down in environment, remains as insoluble solid
Bioaccumulative Potential: Unlikely to bioaccumulate
Mobility in Soil: Binds firmly to soil, minimal vertical movement expected
Other Adverse Effects: None known; avoid uncontrolled releases

Disposal Considerations

Method of Disposal: Collect and reclaim or dispose of in accordance with local, state, national, and international regulations
Disposal of Packaging: Rinse containers, dispose in approved waste facility or recycle where possible
Special Precautions: Do not dispose to drains or water courses; avoid dispersion of powder during waste handling
Waste Codes: Manufacturer/user to determine applicable codes based on local regulations

Transport Information

UN Number: Not classified as hazardous for transport
Proper Shipping Name: Tungsten Disulfide, not hazardous
Transport Hazard Class: None
Packing Group: None
Labels Required: None unless otherwise required by jurisdiction
Special Provisions: Keep container tightly closed and protected from physical damage during transit

Regulatory Information

Safety, Health, and Environmental Regulations: Product not listed as hazardous under most regulations, but dust exposure limits and workplace controls apply
OSHA: General duty to limit dust exposure
TSCA: Listed
REACH: Registered in EU for intended uses
Other Listings: Check local, state, and national chemical regulations for any additional requirements