Material Safety Data Sheet: Molybdenum Trioxide

Identification

Product Name: Molybdenum Trioxide
Other Names: Molybdic Anhydride, Molybdic Oxide
Chemical Formula: MoO₃
CAS Number: 1313-27-5
Recommended Uses: Catalyst in petroleum refining, pigment in ceramics, chemical intermediate, steel alloy additive
Supplier Contact: Safety Office, Emergency Phone: Provided by manufacturer

Hazard Identification

Classification: Acute Toxicity (Inhalation), Specific Target Organ Toxicity, Hazardous to the aquatic environment
Signal Word: Warning
Hazard Statements: Harmful if inhaled or swallowed. Causes serious eye irritation. May cause respiratory irritation. Toxic to aquatic life with long lasting effects.
Pictograms: Exclamation mark, Environmental hazard
Precautionary Statements: Avoid breathing dust. Use only outdoors or in well-ventilated area. Wash hands thoroughly after handling. Wear protective equipment. Avoid release to environment. Dispose of contents in accordance with local regulations.

Composition / Information on Ingredients

Main Component: Molybdenum Trioxide
Concentration: >99% by weight
Impurities: Trace amounts of sodium, potassium, iron oxides
Synonyms: MoO3, Molybdic oxide

First Aid Measures

General Advice: Remove contaminated clothing and wash before reuse.
Inhalation: Move to fresh air immediately. Seek medical attention if symptoms like coughing or shortness of breath develop.
Skin Contact: Wash thoroughly with soap and water. Remove any powdered material from skin.
Eye Contact: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do, continue rinsing, and get medical attention for persistent irritation.
Ingestion: Rinse mouth. Do not induce vomiting. Seek medical advice promptly if large quantities are swallowed or symptoms persist.

Fire-Fighting Measures

Suitable Extinguishing Agents: Use water spray, dry chemical, CO2, or foam for surrounding fire. Substance itself does not burn.
Specific Hazards: Heated material emits irritating and toxic fumes (including molybdenum oxides).
Protective Equipment: Firefighters need self-contained breathing apparatus and full protective gear.
Firefighting Procedures: Cool containers with water if exposed to heat. Avoid water runoff contamination.

Accidental Release Measures

Personal Precautions: Evacuate area. Utilize suitable respiratory protection. Avoid dust generation.
Protective Equipment: Wear gloves, goggles, and protective clothing.
Emergency Procedures: Prevent material from entering water systems.
Clean-Up Methods: Carefully sweep or vacuum spill; avoid excessive dust. Place in suitable containers for disposal.

Handling and Storage

Handling: Minimize dust. Use in well-ventilated areas with local exhaust. Prevent skin and eye contact.
Storage: Store in a tightly sealed container, in a dry, cool, and ventilated space. Keep away from moisture, acids, and incompatible substances.
Incompatible Materials: Strong acids, strong bases, halogens, and reducing agents.

Exposure Controls and Personal Protection

Occupational Exposure Limit: ACGIH TLV: 0.5 mg/m³ (as Mo, inhalable fraction)
Engineering Controls: Use process enclosure, local exhaust ventilation, or other engineering controls to control airborne levels.
Eye Protection: Safety glasses with side shields.
Skin Protection: Protective gloves and work clothing.
Respiratory Protection: Use NIOSH-approved respirator if exposure limits are exceeded or dust is present.
Hygiene Measures: Wash hands and exposed skin after handling.

Physical and Chemical Properties

Appearance: White or slightly yellow powder
Odor: Odorless
Melting Point: 795°C
Boiling Point: 1155°C (sublimes)
Solubility: Slightly soluble in water; readily soluble in alkalis
Density: 4.7 g/cm³ at 20°C
Vapor Pressure: Negligible at room temperature
pH: Slightly acidic in water
Flammability: Not flammable
Partition Coefficient (n-octanol/water): Not applicable

Stability and Reactivity

Chemical Stability: Stable under recommended storage and handling conditions.
Reactivity: Reacts with strong acids and strong bases.
Hazardous Decomposition: May produce toxic metal oxides upon decomposition.
Incompatible Materials: Reducing agents, halogenated acids, organic materials.
Polymerization: Does not occur.

Toxicological Information

Routes of Exposure: Inhalation, ingestion, skin and eye contact
Acute Effects: Inhalation causes respiratory tract irritation and coughing. Eye exposure leads to irritation, redness, and watering. Skin exposure may cause mild irritation.
Chronic Effects: Prolonged exposure may affect liver, kidneys, and lungs. Reports of pneumoconiosis with chronic overexposure.
LD50 (oral, rat): 2689 mg/kg
Carcinogenicity: Not listed as a known human carcinogen
Symptoms: Nausea, headache, sore throat, shortness of breath

Ecological Information

Aquatic Toxicity: Toxic to aquatic life with long lasting effects. Can bioaccumulate in aquatic organisms.
Persistence and Degradability: Inorganic substance; does not degrade easily.
Mobility in Soil: Limited mobility; binds to soil particles.
Other Adverse Effects: Large releases may damage aquatic systems over time.

Disposal Considerations

Disposal Methods: Collect residue and contaminated packaging for hazardous waste disposal in compliance with applicable local, regional, and national regulations.
Special Precautions: Do not discharge to sewers or environment. Consult waste disposal authority for guidance.
Container Handling: Rinse containers before recycling or disposal.

Transport Information

UN Number: 3264 (where classified as corrosive solid, acidic, inorganic, n.o.s.)
Proper Shipping Name: Molybdenum trioxide
Transport Hazard Class: 8 (for certain concentrated forms), otherwise not regulated
Packing Group: III (where applicable)
Environmental Hazards: Marine pollutant
Special Transport Precautions: Use approved packaging to prevent dust release. Keep containers tight during transport. Avoid spillage to prevent environmental harm.

Regulatory Information

US TSCA: Listed
EU REACH: Registered
OSHA Hazard: Hazardous by definition under OSHA 29 CFR 1910.1200
WHMIS Classification (Canada): D2A (Very Toxic Material), D2B (Toxic Material)
SARA 313: Subject to reporting
California Proposition 65: Not listed
Other Regulations: Users should check local and national regulations for any restrictions or obligations concerning this compound.