Material Safety Data Sheet (MSDS) - Tungsten Ditelluride

Identification

Product Name: Tungsten Ditelluride
Chemical Formula: WTe₂
CAS Number: 12067-76-4
Synonyms: Tungsten(IV) telluride, Tungsten ditelluride
Use: Research laboratories, electronics manufacturing, specialty materials sectors
Manufacturer/Supplier: Refer to distributor details on purchasing documentation
Emergency Contact: Refer to country-specific poison control centers and local emergency authorities

Hazard Identification

GHS Classification: Not classified as a hazardous substance under normal laboratory conditions
Health Hazards: Dust can cause mild irritation to eyes, skin, and respiratory tract. Prolonged exposure may increase risk of lung irritation.
Environmental Hazards: Do not let material enter waterways. May have harmful effects on aquatic organisms with long-lasting impacts.
Physical Hazards: Fine powder may present a nuisance dust hazard. Inhalation or contact presents a greater risk if safety measures are ignored.
Signal Word: None required for GHS compliance
Hazard Statements: May cause respiratory irritation. Avoid contact with eyes, skin, and clothing.
Pictograms: No symbol assigned—consult laboratory protocols for safe use instructions.

Composition / Information on Ingredients

Chemical Name: Tungsten Ditelluride
Common Name/Synonyms: WTe₂
CAS Number: 12067-76-4
Percent By Weight: Greater than 99% purity in technical and laboratory grades
Impurities: Trace amounts of tungsten trioxide and elemental tellurium may appear, depending on batch generation

First Aid Measures

Inhalation: Move person to fresh air. Rinse mouth, loosen restrictive clothing, and seek medical support if coughing or irritation continues.
Skin Contact: Wash with plenty of water and gentle soap. Remove any contaminated clothing.
Eye Contact: Rinse eyes cautiously with water for several minutes. Remove contact lenses if present. Continue rinsing.
Ingestion: Rinse mouth (do not induce vomiting). Provide water to drink, and get medical attention if discomfort or irritation continues.
Special Information for Physician: Symptomatic treatment only—chronic exposure assessments recommended if symptoms persist

Fire-Fighting Measures

Suitable Extinguishing Agents: Use dry sand, metal fire extinguishers, or Class D agents. Do not use water or CO₂ due to potential for violent reactions with hot powder.
Hazards from Combustion: In extreme heat, toxic metallic and tellurium oxides may form.
Protective Equipment for Firefighters: Full protective suit and self-contained breathing apparatus must be used.
Specific Methods: Isolate area. Move containers from fire zone if can be done without risk.
Unusual Fire/Explosion Hazards: Fine powder presents a low but possible risk of dust explosion in confined spaces
Combustion Products: Metallic tungsten, tellurium oxides (TeO₂), and irritating gases

Accidental Release Measures

Personal Precautions: Use proper respiratory protection, chemical goggles, and gloves. Avoid creating dust.
Environmental Precautions: Do not allow spillage to reach water sources, drains, or soil.
Cleanup Methods: Sweep or scoop spilled material using non-sparking tools. Place into a labeled disposal container. Use HEPA-filtered vacuum for fine powders.
Reporting: Notify appropriate environmental authorities if a large amount is released or if local laws require reporting

Handling and Storage

Safe Handling: Handle within approved fume hoods or glove boxes. Avoid ingestion, skin and eye contact, and inhalation of dust.
Personal Hygiene: Wash hands thoroughly after handling. Do not eat, drink, or smoke in work areas.
Storage Conditions: Store in tightly closed containers in a cool, dry, well-ventilated area with secondary containment. Material must be kept away from direct sunlight and sources of ignition.
Incompatibilities: Strong acids, oxidizing agents, and strong bases may react with WTe₂ to release toxic fumes

Exposure Controls and Personal Protection

Exposure Limits: No established OSHA or ACGIH exposure limits for Tungsten Ditelluride. Rely on internal guidelines for respirable dust (10 mg/m³ as a nuisance particulate).
Engineering Controls: Work in ventilated area or approved fume hood.
Personal Protective Equipment: Safety goggles, chemical-resistant gloves (nitrile or neoprene), lab coat or protective clothing, and certified particulate respirators if airborne dust levels increase.
Respiratory Protection: Use certified particulate respirator (NIOSH/EN standards) if dust generation exceeds control levels.
Hygiene Measures: Avoid cross-contamination by segregating storage and washing contaminated clothing regularly

Physical and Chemical Properties

Appearance: Gray-black crystalline powder or fragments
Odor: Odorless
Odor Threshold: Not applicable
pH: Not applicable (insoluble in water)
Melting Point: Approximately 1,000 °C
Boiling Point: Not available
Flash Point: Not combustible, but reacts at high temperature
Flammability: Not classified as flammable, can produce toxic fumes during decomposition
Vapor Pressure: Not applicable
Vapor Density: Not applicable
Specific Gravity: Approx. 9.4 (water = 1)
Solubility: Insoluble in water
Partition Coefficient: Not determined
Decomposition Temperature: Decomposes to tungsten and tellurium oxides at elevated temperatures
Viscosity: Not applicable

Stability and Reactivity

Reactivity: Generally stable under room temperature and pressure.
Chemical Stability: Stable in dry, sealed containers under recommended storage conditions.
Possible Hazardous Reactions: Violent reactions may occur with strong acids or oxidizers, particularly at elevated temperatures.
Conditions to Avoid: Exposure to moisture, strong heating, sources of ignition, and incompatible chemicals.
Incompatible Materials: Strong acids, bases, oxidizers
Hazardous Decomposition Products: Metallic tungsten, volatile tellurium oxides, and other irritating gases

Toxicological Information

Likely Routes of Exposure: Inhalation, skin and eye contact, ingestion
Acute Effects: Dust may cause mild eye, skin, and respiratory tract irritation. No acute systemic toxicity reported during normal laboratory handling.
Chronic Effects: Repeated or high-level exposure has not been fully studied, but based on elemental components, prolonged inhalation may aggravate pre-existing respiratory conditions.
Carcinogenicity: Not listed as carcinogenic by IARC, NTP, or OSHA.
Reproductive Toxicity: No reliable data available for WTe₂.
Signs and Symptoms of Exposure: Cough, throat or skin irritation, redness, shortness of breath in dust-heavy atmosphere.
Other Data: Long-term animal toxicity and mutagenicity data unavailable; reasonable caution necessary.

Ecological Information

Eco-toxicity: Material presents risk to aquatic organisms; tellurium compounds have demonstrated toxicity in aquatic environments.
Persistence and Degradability: Poorly biodegradable in natural conditions; remains as particulate for long periods.
Bioaccumulation Potential: Low for tungsten; moderate for tellurium compounds in aquatic species.
Mobility in Soil: Inorganic form is largely immobile in soil.
Other Adverse Effects: Avoid uncontrolled discharge and minimize particulate losses to reduce environmental exposure.

Disposal Considerations

Waste Handling: Collect and keep materials in sealed, compatible containers. Segregate from other lab wastes.
Disposal Procedures: Transport to licensed chemical disposal facility, following state/local guidelines.
Contaminated Packaging: Dispose of packaging as hazardous material if it has been in direct contact with the powder.
Special Precautions: Avoid dust dispersal. Do not allow disposal to public water systems or municipal waste. Large-scale users must consult local regulations prior to any waste processing.

Transport Information

UN Number: Not regulated for transport by road, sea, or air under most jurisdictions.
UN Proper Shipping Name: Not classified as a Dangerous Good.
Transport Hazard Classes: Not applicable.
Packing Group: Not assigned.
Environmental Hazards: Avoid material spillage in rivers, lakes, or groundwater.
Transport Precautions: Use sealed containers, limit shipment with incompatible materials. Prevent packages from crumpling or leaking in transit.

Regulatory Information

International Regulations: Not listed under Annex I of EU Regulation (EC) No 1272/2008 (CLP). Not classified as a substance of very high concern according to REACH.
US Regulations: Not regulated as a hazardous chemical under OSHA HazCom or SARA Title III. Not listed under CERCLA, TSCA, or RCRA.
Canadian Regulations: Not listed as a controlled product under WHMIS. Review local provincial legislation.
Labeling Requirements: Include product identifier, hazard warnings, supplier identification, and necessary safety precautions on primary label as per workplace requirements.
Inventory Status: Check listing in local chemical inventories (US TSCA, EU EINECS/ELINCS, etc.) for latest registration updates.