Material Safety Data Sheet (MSDS): Molybdenum Telluride

Identification

Product Name: Molybdenum Telluride
Chemical Formula: MoTe₂
Synonyms: Molybdenum ditelluride
Recommended Use: Semiconductor materials, research, solid-state devices
Manufacturer: Refer to supplier or producer information
CAS Number: 12058-20-7
Emergency Contact: National Poison Control Center, company safety officer

Hazard Identification

Classification: Acute toxicity (oral, inhalation), Skin and eye irritation, Possible carcinogen
Label Elements: Skull and crossbones (toxic), Exclamation mark (irritant)
Signal Word: Danger
Hazard Statements: Harmful if swallowed or inhaled, causes skin and eye irritation, suspected of causing cancer on prolonged exposure
Precautionary Statements: Wash thoroughly after handling, avoid breathing dust, use protective gloves and equipment, avoid release to environment

Composition / Information on Ingredients

Chemical Name: Molybdenum ditelluride
Purity: Typically above 99%
Component Percentage: Molybdenum 32-34%, Tellurium 66-68% by atomic ratio
Impurities: Possible traces of other metals, dust, or oxides from packaging or storage

First Aid Measures

Inhalation: Remove victim to fresh air immediately, keep warm and at rest, seek medical advice for any signs of respiratory distress
Skin Contact: Remove contaminated clothing, wash skin thoroughly with soap and water, seek medical attention if irritation develops
Eye Contact: Rinse eyes gently with water for 15-20 minutes, hold eyelids open, remove contact lenses if present and easy to do, seek medical help
Ingestion: Rinse mouth, never induce vomiting unless instructed by a professional, seek immediate medical care
Notes to Physician: Treat symptoms, support respiratory and cardiovascular functions, monitor exposure pathways

Fire-Fighting Measures

Suitable Extinguishing Media: Use dry chemical, CO₂, or foam for small fires; avoid water streams directly on material
Special Hazards: Toxic or corrosive gases such as TeO₂ may form on heating or combustion
Protective Equipment: Full protective clothing and self-contained breathing apparatus for fire-fighters
Further Advice: Cool exposed containers with water spray from a safe distance, isolate area if possible

Accidental Release Measures

Personal Precautions: Evacuate unnecessary personnel, ventilate the area, use appropriate protective gear—respiratory protection, gloves, goggles
Environmental Precautions: Prevent the spread of powder or dust, keep away from drains, surface water, and soil
Method for Containment: Collect spillage using proper tools (shovel, vacuum with HEPA filter), avoid generating dust, place in a tightly sealed container
Cleanup Procedures: Wash area with water and mild detergent after spill removal, dispose according to regulations

Handling and Storage

Handling: Use in well-ventilated areas, avoid skin and eye contact, minimize dust generation, handle with personal protective equipment
Storage: Store in cool, dry location away from incompatible substances (strong acids, oxidizers), keep tightly sealed
Storage Conditions: Protect from moisture and direct sunlight, keep containers labeled and secure
Other Precautions: Inspect containers regularly for leaks, train personnel on safe handling procedures

Exposure Controls and Personal Protection

Exposure Limits: OSHA/NIOSH/ACGIH or specific workplace standards for molybdenum and tellurium compounds
Engineering Controls: Local exhaust ventilation, fume hoods in laboratories, process enclosures for large-scale use
Personal Protective Equipment: Nitrile or rubber gloves, safety goggles or face shield, long-sleeved lab coats or coveralls, suitable respiratory protection for dust
Hygiene Measures: Wash thoroughly after handling, do not eat, drink, or smoke near material, change contaminated clothing

Physical and Chemical Properties

Appearance: Black or dark gray powder or crystalline solid
Odor: Odorless
Melting Point: Approximately 900°C
Boiling Point: Decomposes on heating
Density: 7.8 g/cm³ (at 25°C)
Solubility: Insoluble in water, soluble in strong acids
Vapor Pressure: Not significant at room temperature
pH: Not applicable
Other Properties: Stable under recommended conditions, poor electrical conductivity in bulk

Stability and Reactivity

Chemical Stability: Stable under normal temperatures and pressures
Conditions to Avoid: Exposure to moisture, extreme heat, open flames, strong acids, oxidizers
Incompatible Materials: Strong oxidizing agents, mineral acids, halogens
Hazardous Decomposition Products: Toxic fumes of tellurium oxides (TeO₂), molybdenum oxides on high heat
Polymerization: Will not occur under normal conditions

Toxicological Information

Acute Toxicity: Harmful if swallowed or inhaled, higher toxicity than elemental molybdenum or tellurium alone
Routes of Exposure: Inhalation, ingestion, skin and eye contact
Symptoms: Eye, skin, and respiratory irritation, gastrointestinal discomfort, metallic taste, headache
Chronic Effects: Prolonged exposure may affect liver, kidney, nervous system functions, target organ damage not fully established for compound form
Carcinogenicity: Not classified as carcinogenic by IARC; some tellurium compounds have shown suspect effects in animal studies
Mutagenicity/Reproductive Effects: Not well studied; use caution until more data available

Ecological Information

Ecotoxicity: Harmful to aquatic life in larger quantities, persists in environment
Mobility in Soil: Low mobility due to strong binding to soil particles
Bioaccumulation: Low bioaccumulation expected in aquatic organisms, some potential for uptake by plants
Degradability: Inorganic compound, not readily biodegradable
Other Environmental Hazards: May disrupt local microbiota and plant roots on release

Disposal Considerations

Waste Treatment Methods: Chemical waste must be collected and disposed according to local, regional, or national regulations
Container Disposal: Containers should be triple-rinsed, defaced, and disposed under hazardous waste protocols
Recommended Disposal: Send to licensed hazardous waste treatment facility; avoid landfilling or incineration without controls
Other Recommendations: Keep records of disposal, utilize authorized contractors familiar with heavy metal-containing wastes

Transport Information

UN Number: Not assigned for MoTe₂ specifically, but refer to specifications for heavy metal compounds
Proper Shipping Name: Molybdenum Telluride, or inorganic solid, n.o.s.
Transport Hazard Class: 6.1 Toxic substances (if classified)
Packing Group: III (low danger)
Marine Pollutant: Not classified
Special Precautions: Ensure packaging prevents dust release, complies with local and international transport regulations, label containers clearly

Regulatory Information

OSHA Status: Regulated as a hazardous substance under OSHA Hazard Communication Standard
TSCA: Listed on the U.S. TSCA Inventory
SARA Title III: Not listed as an extremely hazardous substance; may be reportable under general chemical inventory
REACH: Covered under European Union chemical regulations; safety assessment required
Other Requirements: Consult regional and national guidelines for use, environmental release, and workplace exposure limits