Material Safety Data Sheet: Phosphotungstic Acid

Identification

Product Name: Phosphotungstic Acid
Chemical Formula: H₃PW₁₂O₄₀
CAS Number: 12501-23-4
Synonyms: Tungstophosphoric acid, PTA
Application: Often found in laboratories for staining in microscopy, catalyst in chemical syntheses, and analytical chemistry.
Supplier Identification: Refer to your laboratory or chemical provider for local information.
Emergency Contact: Use 24-hour medical and fire emergency services in your region for prompt assistance.
Recommended Use: Laboratory chemicals, manufacturing processes, research development.

Hazard Identification

Classification: Corrosive, causes severe skin burns and serious eye damage (GHS05), harmful if swallowed or inhaled.
GHS Label Elements: Danger symbol, Corrosive pictogram.
Hazard Statements: Causes severe skin burns and eye damage, harmful if ingested or dust is inhaled, may cause respiratory irritation.
Precautionary Statements: Store locked up, avoid breathing dust, wash hands thoroughly after handling, wear protective gloves/clothing/eye protection/face protection.
Potential Health Effects: Eye contact leads to burns, redness, pain, and possible loss of vision. Skin contact causes burns, blistering, and scarring. Inhalation triggers coughing, breathing difficulty, and throat irritation. Ingestion produces abdominal pain, burns to gastrointestinal tract, vomiting, diarrhea, and possible serious systemic effects.

Composition / Information on Ingredients

Chemical Name: Phosphotungstic Acid
Concentration: Typically used as pure solid or as an aqueous solution, always >95% by weight in laboratory-grade containers.
Impurities: Small traces of other tungstate or phosphate compounds may be present but rarely affect the chemical’s hazards profile.
Inert Material: No significant inert materials in most commercial samples.
Molecular Weight: 2,880.06 g/mol.

First Aid Measures

Inhalation: Move to fresh air. Allow person to rest. Seek immediate medical attention if symptoms develop.
Skin Contact: Remove contaminated clothing, rinse skin with plenty of water for 15 minutes minimum. Call a doctor at once.
Eye Contact: Promptly flush eyes with plenty of water for at least 15 minutes, lifting eyelids. Do not allow victim to rub eyes. Get emergency medical help.
Ingestion: Rinse mouth. Do not induce vomiting. Never try to give anything by mouth to an unconscious person. Seek urgent medical care.
Note to Physicians: Immediate medical attention is necessary for severe burns or if ingested. Treat based on symptoms and get the material safety data information.

Fire-Fighting Measures

Suitable Extinguishing Media: Dry chemical powder, carbon dioxide, alcohol-resistant foam. Water sprays may be used for cooling containers.
Unsuitable Extinguishing Media: Do not use large amounts of water on small spills or fires to prevent runoff.
Special Hazards: Non-combustible. Upon heating, may emit toxic fumes of tungsten oxides and phosphorous oxides.
Protective Equipment for Firefighters: Full protective gear including self-contained breathing apparatus.
Firefighting Procedures: Remain upwind, evacuate area, and prevent runoff from water used for cooling from entering drains and waterways.

Accidental Release Measures

Personal Precautions: Evacuate non-essential personnel. Avoid dust formation. Wear appropriate PPE including gloves, eye protection, and respirator where required.
Environmental Precautions: Prevent further leakage or spillage. Prevent entry into sewers, surface waters, or soil.
Methods for Clean-Up: Vacuum or carefully sweep up spilled material, avoiding dust generation. Place in appropriate waste disposal containers. Wash spill area with plenty of water after material pickup is complete.
Additional Guidance: Dispose according to local regulations. Use ventilation during clean-up for larger spills to avoid inhalation of dust.

Handling and Storage

Safe Handling Advice: Use in a chemical fume hood. Avoid breathing dust, contact with skin, eyes, and contaminated clothing. Practice good hygiene, wash thoroughly after use, keep chemical containers properly labeled.
Storage Conditions: Store locked up in tightly closed containers in cool, dry, well-ventilated spaces, away from incompatible materials such as organic compounds, bases, and reducing agents.
Specific End Uses: Limited to research, analysis, and controlled industrial settings. Never use for food, drug, or household purposes.
Storage Incompatibilities: Keep away from bases and organic materials to avoid dangerous reactions.

Exposure Controls and Personal Protection

Engineering Controls: Work in well-ventilated areas, preferably within a chemical fume hood. Use local exhaust or general dilution ventilation to keep airborne levels low.
Personal Protective Equipment: Chemical-resistant gloves (nitrile, neoprene), safety goggles or face shield, lab coats. Use a NIOSH-approved particulate respirator if dust is present.
Occupational Exposure Limits: Not established by OSHA or ACGIH but control exposure as low as reasonably achievable.
Hygiene Measures: Regular hand washing and removal of contaminated clothing before eating, drinking, or smoking.
Other Protective Measures: Eye wash stations and safety showers should be available in all working areas using this material.

Physical and Chemical Properties

Appearance: White to pale yellow crystalline solid.
Odor: Odorless.
pH: Strongly acidic in water solution.
Melting Point: Decomposes before melting.
Boiling Point: Not applicable, substance decomposes.
Solubility: Highly soluble in water, ethanol, and ether.
Vapor Pressure: Not applicable.
Density: Approximately 2.5 g/cm³.
Decomposition Temperature: Decomposes above 200°C.
Other Data: Non-flammable and does not support combustion.

Stability and Reactivity

Chemical Stability: Stable under recommended storage and handling conditions.
Conditions to Avoid: Prolonged exposure to air, moisture, heat; contact with incompatible substances.
Incompatible Materials: Strong bases, strong reducing agents, organic materials, and alkali metals.
Hazardous Decomposition Products: Phosphorus oxides, tungsten oxides, possibly toxic fumes when heated strongly.
Reactivity: Reacts with bases and reducing agents with possible vigorous or violent reactions.

Toxicological Information

Routes of Exposure: Inhalation, ingestion, skin and eye contact.
Acute Toxicity: Corrosive, can cause burns, harmful effects seen at relatively low doses if ingested.
Chronic Effects: No evidence of chronic toxicity in typical laboratory or workplace use, but repeated or prolonged exposure increases the risk of local effects (ulceration, dermatitis).
Symptoms: Burning pain, redness, ulceration, gastrointestinal distress, breathing difficulty.
Carcinogenicity: No data to indicate carcinogenic risk to humans.
Mutagenicity: Studies insufficient to classify for genetic effects.
Other Data: May cause tissue destruction with longer exposure.

Ecological Information

Ecotoxicity: Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment due to acidity and presence of heavy metals.
Persistence and Degradability: Not readily biodegradable. Phosphotungstic acid persists in the environment and dissociates to tungstate and phosphate ions.
Bioaccumulation Potential: Low potential for accumulation in aquatic life.
Mobility in Soil: Dissolves and migrates readily through soil and water.
Other Adverse Effects: Release into waterways can upset aquatic pH and metal ion balances.

Disposal Considerations

Waste Treatment Methods: Collect all waste and dispose through licensed hazardous waste contractor. Neutralize acids with suitable agents prior to disposal only with proper chemical control.
Contaminated Packaging: Triple rinse containers, remove labels, and send to hazardous waste processor.
Disposal Recommendations: Always abide by local, state, and federal regulations.
Other Guidance: Never pour into drains, waterways, or soil. Keep solution and residues in identified chemical waste containers awaiting pickup.

Transport Information

UN Number: 3264 – Corrosive liquid, acidic, inorganic, n.o.s. (containing phosphotungstic acid)
UN Proper Shipping Name: Corrosive liquid, acidic, inorganic, n.o.s.
Transport Hazard Class: 8 (Corrosive substances)
Packing Group: II (causing severe injury on substantial exposure)
Environmental Hazards: Considered hazardous for aquatic environments.
Transport Precautions: Ship only in tightly sealed, corrosion-resistant containers with clear hazard labeling. Secure containers from tipping. Avoid temperature extremes during shipment.

Regulatory Information

OSHA Status: Regulated under 29 CFR 1910.1200 (Hazard Communication).
TSCA (United States): Listed on Toxic Substances Control Act inventory.
EU Regulations: Classified as dangerous under Regulation (EC) No 1272/2008 (CLP Regulation); requires hazard labeling and SDS (Safety Data Sheet) provision for industrial and laboratory settings.
Other International Regulations: Subject to Chemical Weapon Convention restrictions for dual-use chemicals in significant volumes.
Workplace Exposure Limits: No established OSHA PEL; handle as a hazardous material per best practices outlined above.
Other Guidance: Always refer to federal, state, and local chemical handling laws for additional requirements on use, handling, and storage.