Material Safety Data Sheet: Ammonium Tungstate

Identification

Product Name: Ammonium Tungstate
Chemical Formula: (NH₄)₁₀W₁₂O₄₁·xH₂O
Synonyms: Ammonium paratungstate, APT
CAS Number: 11120-25-5
Use: Catalyst production, metal finishing, ceramics, pigment manufacture, metal processing, analytical reagent
Manufacturer: [Provide name and contact of supplier]
Emergency Contact: [Company emergency contact phone number]

Hazard Identification

Hazard Classification: Eye irritation (Category 2), Specific target organ toxicity – Single exposure (Category 3)
Hazard Pictogram: Exclamation mark (GHS07)
Signal Word: Warning
Hazard Statements: Causes eye irritation. May cause respiratory irritation.
Precautionary Statements: Avoid breathing dust or fumes. Wash hands thoroughly after use. Use only outdoors or in well-ventilated area. Wear eye protection.
Routes of Exposure: Inhalation, ingestion, skin and eye contact
Appearance: White crystalline powder, odorless.
Potential Health Effects: May cause mild to moderate eye and upper respiratory tract irritation; prolonged exposure could irritate skin; low acute toxicity but inhaling large amounts could affect lungs.

Composition / Information on Ingredients

Chemical Name: Ammonium Tungstate
CAS Number: 11120-25-5
Concentration: >98% by weight
Impurities: May contain trace sodium, potassium, or other alkali salts depending on production source, but present at <1%
Molecular Weight: Variable, depending on water of hydration (approx. 2964 g/mol for decahydrate form)

First Aid Measures

Inhalation: Move person into fresh air. Seek medical attention if irritation or breathing difficulty persists.
Skin Contact: Wash thoroughly with soap and water. Remove contaminated clothing. Get medical advice if irritation develops.
Eye Contact: Rinse gently with water for 15 minutes, holding eyelids open. Remove contact lenses if possible. Seek medical attention if irritation continues.
Ingestion: Rinse mouth with water. Do not induce vomiting unless directed by medical personnel. Get medical attention for large ingestions or if feeling unwell.
Most Important Symptoms: Eye redness or watering, scratchy throat from inhalation, mild skin redness in prolonged contact.

Fire-Fighting Measures

Suitable Extinguishing Media: Water spray, dry chemical powder, carbon dioxide, foam
Unsuitable Extinguishing Media: None known for product
Hazards from Combustion: Product itself is not flammable. Heating releases ammonia gas and tungsten oxides. Ammonia may irritate respiratory tract.
Protective Equipment: Wear self-contained breathing apparatus and full protective gear.
Special Procedures: Move containers away from fire area. Cool tanks with water spray.
Other Notes: Confined fire may produce hazardous fumes; avoid inhalation of smoke or gases.

Accidental Release Measures

Personal Precautions: Avoid breathing dust. Wear suitable protective clothing, gloves, goggles, dust mask or respirator.
Environmental Precautions: Prevent entry into drains, watercourses, and soil. Notify authorities if spill enters environment.
Cleaning Methods: Sweep or vacuum up material; avoid dust formation. Place into labeled containers for disposal.
Decontamination: Wash area with water to remove residues. Prevent runoff from entering sewers.
Procedural Controls: Use local exhaust ventilation in spill site if available. Prohibit access to unprotected personnel.

Handling and Storage

Handling: Wear recommended PPE. Use only in well-ventilated areas or fume hoods. Avoid creating dust or aerosol. No smoking or eating in work area. Handle with care to prevent spillage.
Storage: Store in original, tightly closed containers. Keep in a dry, cool, well-ventilated space, separate from acids and ammonium salt-incompatible substances. Keep away from direct sunlight and moisture. Label storage containers clearly.
Incompatibilities: Do not mix with strong acids, strong oxidizers, or combinations that release ammonia. Avoid storing near food and drink.

Exposure Controls and Personal Protection

Occupational Exposure Limits: No OSHA PEL or ACGIH TLV established for ammonium tungstate. Tungsten compounds (as W): OSHA PEL 5 mg/m³ (soluble), ACGIH TLV 1 mg/m³ (soluble, inhalable)
Engineering Controls: Provide adequate ventilation, local exhaust recommended. Use enclosed processes if possible.
Personal Protective Equipment: Safety glasses or chemical goggles; gloves (nitrile or neoprene); lab coat or protective clothing; dust mask or respirator (NIOSH-approved P1 or equivalent) if dust is produced.
Hygiene Measures: Wash hands after use, before eating or restroom breaks. Remove contaminated clothing and wash before reuse.
Environmental Controls: Keep process and storage areas contained to avoid emissions.

Physical and Chemical Properties

Appearance: White crystalline solid or powder
Odor: Odorless
pH (1% aqueous): 5.0–7.0
Melting Point: Decomposes before melting (starts to decompose above 250°C)
Boiling Point: Not applicable (decomposes before boiling)
Relative Density: Approx. 2.89 g/cm³
Solubility: Soluble in water; insoluble in most organic solvents
Vapor Pressure: Not applicable
Evaporation Rate: Not applicable
Flammability: Not flammable
Decomposition Products: Ammonia, tungsten oxides on heating
Partition Coefficient (n-octanol/water): Not determined

Stability and Reactivity

Chemical Stability: Stable under normal conditions. Sensitive to moisture over long periods.
Conditions to Avoid: Excessive heat, open flames, strong acids, incompatible materials
Materials to Avoid: Strong oxidizers, strong acids, alkali metals
Hazardous Decomposition: Heating releases ammonia, nitrogen oxides, and tungsten oxide fumes.
Polymerization: Does not occur.
Reactivity: May react with strong acids to give off ammonia or toxic gases; otherwise not highly reactive.

Toxicological Information

Acute Toxicity: Oral LD₅₀ (rat): >5000 mg/kg (low acute toxicity)
Routes of Exposure: Inhalation, ingestion, skin and eye contact
Potential Effects: Inhalation may cause mild respiratory irritation. Eye exposure can lead to redness, discomfort. Skin contact usually harmless but repeated or prolonged contact may irritate. Ingesting high amounts could upset stomach.
Chronic Effects: No evidence of carcinogenicity or permanent toxicity in normal occupational exposure; excessive inhalation over months may affect lungs.
Other Information: Not classed as mutagenic or teratogenic. No evidence for reproductive toxicity in animal studies. Not classified as hazardous under EU CLP for chronic effects.

Ecological Information

Ecotoxicity: Not acutely toxic to aquatic organisms at likely environmental concentrations. LC₅₀/EC₅₀ (fish/Daphnia): >100 mg/L.
Persistence and Degradability: Inorganic compound, does not biodegrade; dissociates in water to ions.
Bioaccumulative Potential: Low, unlikely to bioaccumulate in living organisms.
Mobility in Soil: Mobile in water; may leach if released.
Other Adverse Effects: Release into waterways should be minimized out of caution, as high concentrations could affect aquatic invertebrates over time.

Disposal Considerations

Waste Methods: Collect and dispose of material in accordance with local, regional, national regulations. Avoid disposal to sewer, surface water, or soil.
Disposal of Packaging: Empty containers can be triple rinsed then recycled or disposed as hazardous waste.
Unwanted Product: If small amounts, can be diluted then discharged to properly permitted treatment plant, after consulting environmental protection authority.
Precautions for Disposal: Do not incinerate with regular trash. Control dust generation at recycling or disposal site.
European Waste Catalogue (EWC): 06 03 14 – Solid salts and solutions containing heavy metals.

Transport Information

UN Number: Not regulated
UN Proper Shipping Name: Not classified as dangerous goods
Transport Hazard Class: None
Packing Group: None
Marine Pollutant: No
Other Transport Measures: Store sealed to avoid spillage. Ensure container labeling meets local rules.
Special Precautions: Keep container tightly closed, dry, secure against breakage in transit; handle with appropriate PPE during transfer.

Regulatory Information

Classification: Not classified under major international dangerous goods regulations (IMDG, ICAO/IATA, ADR/RID).
Labeling (GHS): Eye Irritation Category 2, Specific Target Organ Toxicity (single exposure) Category 3.
OSHA Hazard Communication: Irritant
TSCA: Listed
REACH Status (EC): Pre-registered
Other Regulations: Not covered under any specific SARA Title III sections. Not listed as carcinogen by IARC/NTP/OSHA.
Local Requirements: Compliance with workplace, environmental and safety regulations required in country of use. Obtain appropriate permits where needed.