Material Safety Data Sheet: Tungsten Trioxide

Identification

Product Name: Tungsten Trioxide
Chemical Formula: WO₃
CAS Number: 1314-35-8
Molecular Weight: 231.84 g/mol
Synonyms: Tungstic acid anhydride, Tungsten(VI)-oxide
Manufacturer: Commercial chemical suppliers worldwide
Recommended Use: Ceramics, semiconductor engineering, glass manufacturing, pigment, catalyst, electrochromic devices
Restrictions of Use: Industrial and laboratory uses only

Hazard Identification

Classification: Not classified as a hazardous substance according to GHS criteria
Main Hazards: Respiratory tract irritation in high airborne concentrations, possible eye irritation, nuisance dust hazard
Routes of Exposure: Inhalation, eye contact, skin contact, ingestion
Signal Word: None required under GHS
Hazard Statements: Dust may cause mechanical irritation to eyes, nose, throat
Precautionary Statements: Use only with adequate ventilation, avoid creating dust, wash thoroughly after handling
Label Elements: No pictograms required for labeling

Composition / Information on Ingredients

Component: Tungsten Trioxide
Chemical Identity: WO₃
CAS Number: 1314-35-8
Concentration: 99–100% by weight
Impurities: Trace oxides of tungsten or other metals depending on manufacturing

First Aid Measures

Inhalation: Move to fresh air, seek medical attention for cough, shortness of breath or prolonged symptoms
Skin Contact: Wash thoroughly with soap and water, remove contaminated clothing
Eye Contact: Rinse cautiously with water for at least 15 minutes, remove contacts as possible, seek medical attention if discomfort persists
Ingestion: Rinse mouth, do not induce vomiting, seek advice from poison control or medical personnel
Note to Physicians: Treat symptomatically, no special antidote needed for tungsten compounds

Fire-Fighting Measures

Flammability: Non-combustible
Suitable Extinguishing Media: Use media appropriate for surrounding fire (water spray, foam, dry chemical, carbon dioxide)
Special Hazards: Will not burn, powder can collect and form dust clouds but poses low risk
Firefighter Protection: Wear self-contained breathing apparatus in case of fire, avoid inhaling dust or combustion products
Hazardous Combustion Products: Tungsten oxides, potentially irritating fumes if heated in fire conditions
Explosion Data: Non-explosive under normal conditions

Accidental Release Measures

Personal Precautions: Use dust mask, gloves, and safety goggles
Environmental Precautions: Prevent entry into drains, soil or waterways due to persistence in environment
Clean-Up Methods: Sweep up material with minimal dust generation using HEPA vacuum or wet methods, place in labeled container for disposal
Avoidance Methods: Avoid dry sweeping, use plastic tools to minimize sparking
Decontamination: Wash area with water after dry clean-up

Handling and Storage

Handling: Keep container tightly closed, minimize dust generation
Hygiene: Wash hands after handling, do not eat or drink while handling
Storage Conditions: Store in cool, dry area with good ventilation
Avoid: Incompatible materials such as strong acids, bases, reducing agents
Packaging Materials: Store in original or corrosion-resistant containers, label clearly

Exposure Controls and Personal Protection

Occupational Exposure Limits: Tungsten insoluble compounds (OSHA PEL: 5 mg/m³ TWA; ACGIH TLV: 5 mg/m³ TWA, 10 mg/m³ STEL)
Engineering Controls: Local exhaust ventilation, process enclosure
Personal Protective Equipment (PPE): Safety glasses, gloves, lab coat, dust mask (N95 or higher when dust is generated)
Respiratory Protection: Use approved particulate respirator if exposure limit exceeded
Eye/Face Protection: Chemical safety goggles or face shield for bulk handling
Hand Protection: Protective gloves (nitrile, latex or PVC)

Physical and Chemical Properties

Appearance: Yellow crystalline powder
Odor: Odorless
Odor Threshold: Not applicable
pH: Not applicable (insoluble in water)
Melting Point: 1473 °C (2683 °F)
Boiling Point: 1700 °C (decomposes)
Flash Point: Non-flammable
Evaporation Rate: Not applicable
Flammability: Non-flammable
Vapor Pressure: Negligible at ambient temperature
Vapor Density: Not applicable
Solubility: Insoluble in water, slightly soluble in alkalis
Partition Coefficient: Not available
Auto-ignition Temperature: Not applicable
Decomposition Temperature: Decomposes above 1700 °C
Viscosity: Not applicable

Stability and Reactivity

Stability: Chemically stable under normal storage and handling conditions
Incompatible Materials: Strong acids, reduced metals, strong reducing agents
Conditions to Avoid: Excess dust generation, contact with incompatible substances
Hazardous Decomposition Products: Tungsten oxides (toxic fumes possible at high temperatures)
Polymerization: Will not occur
Reactivity: Non-reactive under normal use; reacts slowly with bases

Toxicological Information

Routes of Exposure: Inhalation, skin contact, eye contact, ingestion
Acute Toxicity: Low acute toxicity, no known LD₅₀ for oral, dermal or inhalation in humans; animal studies show minimal effects at high oral doses
Chronic Effects: Prolonged exposure to dust can cause respiratory tract irritation, rarely fibrotic lung disease in chronic heavy occupational exposures
Carcinogenicity: Not listed by IARC, NTP, OSHA as a carcinogen
Mutagenicity: No evidence from available studies
Reproductive Toxicity: No evidence from available studies
Sensitization: Not a skin or respiratory sensitizer
Other Effects: In some studies, high occupational exposure associated with mild nose and throat irritation

Ecological Information

Environmental Fate: Practically insoluble in water, persists in soil and sediment
Aquatic Toxicity: No acute aquatic toxicity expected at environmentally relevant concentrations
Bioaccumulation: Potential for accumulation in plants and soil organisms, extremely low in aquatic organisms
Mobility in Soil: Low mobility, adsorbs strongly to soil particles
Persistence and Degradability: Not biodegradable, remains as mineral in the environment
Ecotoxicity: Chronic exposure can affect aquatic organisms in laboratory studies at high concentrations

Disposal Considerations

Waste Disposal: Dispose of according to local, state, and federal regulations; avoid release into natural waterways
Container Disposal: Empty containers can contain residue; treat as hazardous waste
Special Considerations: Use licensed waste contractor for large volumes; check for recycling options where available
Methods: Landfilling or stabilization in solid waste allowed in line with environmental regulations; consult waste authority for specific recommendations

Transport Information

UN Number: Not classified as dangerous for transport
Transport Hazard Class: Not regulated
Packing Group: Not applicable
Proper Shipping Name: Tungsten trioxide
Hazard Labels: None required
Special Precautions: Use secure packaging to minimize dust dispersal during transit
Transport in Bulk: Generally permitted without special requirements, maintain engineering controls to prevent spillage

Regulatory Information

TSCA Inventory: Listed on US TSCA
REACH Status: Registered under EU REACH
OSHA: Not considered hazardous under OSHA Hazard Communication Standard
SARA Title III: Not listed as reportable under SARA 302/304, not subject to Section 313 reporting
California Proposition 65: Not listed
Other International Regulations: Listed on appropriate chemical inventories in Canada, Australia, Japan, China, South Korea
Workplace Labelling: SDS must be available at the worksite and product clearly labeled