Sodium Thiosulfate (Na₂S₂O₃) is a high-purity, water-soluble inorganic compound widely recognized for its versatility, chemical stability, and broad range of applications across industrial, commercial, and medical sectors. Known for its reducing and complexing properties, Sodium Thiosulfate serves as a crucial chemical in photography, water treatment, chemical synthesis, medical applications, and laboratory processes. Its excellent solubility, stability, and safe handling characteristics make it a preferred choice for manufacturers and industrial users seeking consistent performance and high-quality results.

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Chemical and Physical Properties

Sodium Thiosulfate is a white crystalline solid or granules that is highly soluble in water. It is available in both pentahydrate (Na₂S₂O₃·5H₂O) and anhydrous forms, with the pentahydrate form being more commonly used due to its stability and ease of handling.

Key Properties Include:

Chemical Formula: Na₂S₂O₃ (pentahydrate: Na₂S₂O₃·5H₂O)

Appearance: White crystalline powder or granules

Solubility: Highly soluble in water, slightly soluble in glycerol

pH (1% aqueous solution): 5–6.5 (slightly acidic to neutral)

Density: 1.667 g/cm³ (pentahydrate)

Melting Point: 48–50°C (pentahydrate)

Odor: Odorless

Stability: Stable under normal conditions; avoid contact with strong acids and oxidizers

These properties make Sodium Thiosulfate ideal for applications requiring controlled chemical reactions, reducing environments, or neutralization of halogens.

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Industrial and Commercial Applications

1. Photography and Photographic Fixing

Sodium Thiosulfate is a vital chemical in traditional photography as a photographic fixer:

Dissolves unexposed silver halides from photographic films and papers

Ensures permanent image formation without discoloration

Stabilizes prints and negatives, preventing degradation over time

Commonly referred to as “hypo” in photographic industries

Its effectiveness and reliability make it indispensable in film processing labs and commercial photography.

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2. Water Treatment Applications

Sodium Thiosulfate is extensively used in water treatment processes to:

Neutralize residual chlorine in municipal and industrial water

Reduce oxidizing agents in wastewater streams

Protect sensitive equipment and aquatic life by removing excess halogens

Serve as a dechlorinating agent in pools, laboratories, and aquaculture

This ensures safe, clean, and chemically balanced water in various applications.

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3. Medical and Pharmaceutical Uses

In the medical field, Sodium Thiosulfate is valued for its detoxifying and therapeutic properties:

Antidote for cyanide poisoning, converting toxic cyanide into less harmful thiocyanate

Used in chemotherapy treatments to reduce side effects of cisplatin

Administered for calciphylaxis and certain kidney-related conditions

Acts as a neutralizing agent for oxidative drugs and disinfectants

Its safety and effectiveness in therapeutic applications make it a critical pharmaceutical agent.

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4. Chemical Industry and Laboratory Applications

Sodium Thiosulfate is widely used as a reducing agent, titrant, and complexing agent:

Reduces halogens and iodine in chemical reactions

Serves as a key reagent in iodometry and analytical chemistry

Used in the synthesis of thiourea, thiosulfonates, and other sulfur-containing compounds

Acts as a stabilizer for oxidizing agents in laboratory and industrial processes

Its versatility ensures precise and controlled chemical reactions in scientific and industrial settings.

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5. Photographic, Cleaning, and Textile Uses

Beyond industrial applications, Sodium Thiosulfate is utilized in:

Textile bleaching processes to remove residual chlorine

Cleaning and neutralizing agents in laboratories and households

Stabilizing solutions and reducing chemical residues on treated fabrics and surfaces

Its safe handling and effectiveness make it suitable for commercial, household, and industrial cleaning formulations.

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Advantages of Sodium Thiosulfate

High-purity grade ensures consistent and reliable performance

Water-soluble and easy to handle

Versatile across multiple industries, including photography, water treatment, pharmaceuticals, chemical manufacturing, and textiles

Acts as a reducing, neutralizing, and complexing agent

Safe, non-toxic, and environmentally friendly when used properly

Stable and reliable for industrial and laboratory applications

These advantages make Sodium Thiosulfate a trusted chemical for industrial users, manufacturers, laboratories, and medical professionals worldwide.

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Handling and Storage

To maintain chemical stability and performance:

Store in a cool, dry, and well-ventilated area

Keep containers tightly sealed to prevent moisture absorption

Avoid contact with strong acids, oxidizing agents, and reactive chemicals

Use personal protective equipment (PPE) including gloves, goggles, and masks during handling

Prevent inhalation or direct skin contact

Proper storage ensures long shelf life, optimal performance, and safe usage across all applications.

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Conclusion

• Sodium Thiosulfate (Na₂S₂O₃) is a versatile, high-performance, and eco-friendly chemical with wide-ranging applications in photography, water treatment, pharmaceuticals, chemical synthesis, textiles, and cleaning industries. Its reducing, neutralizing, and complexing properties, along with water solubility, chemical stability, and safety, make it an essential ingredient for industrial, commercial, and medical use. Sodium Thiosulfate continues to be a trusted, high-quality solution for manufacturers, laboratories, and healthcare professionals worldwide, offering reliable performance, efficiency, and environmentally responsible functionality.