Chemical Name: Sodium Thiosulfate

Chemical Synonyms: Sodium Hyposulfite; Hypo; Disodium Thiosulfate

CAS No.:  7772-98-7

Molecular Formula: Na₂O₃S₂ (Na₂S₂O₃)

Molecular Weight: 158.11 g/mol

Product Overview

Sodium Thiosulfate (CAS 7772-98-7), also known as Sodium Hyposulfite or Hypo, is an inorganic reducing agent widely used in photographic processing, water treatment, and industrial applications. This grade is anhydrous (Na₂S₂O₃, MW 158.11), distinguishing it from the more common pentahydrate form. It serves as an effective chlorine neutralizer, photographic fixer, and analytical reagent. With assay ≥99% and compliance with industrial standards, it is suitable for photography, water dechlorination, and chemical synthesis.

Key Specifications

Applications

• Photographic Processing: Standard photographic fixer for film and paper processing, dissolving silver halides .

• Water Treatment: Dechlorination agent for tap water, aquariums, swimming pools, and spas .

• Analytical Chemistry: Reducing agent for iodometric titrations and volumetric analysis .

• Industrial Bleaching: Antichlor after bleaching of cotton fabrics, pulp, and paper .

• Gold Extraction: Used in gold leaching and recovery processes .

Why Choose This Product

• Anhydrous Form: Higher active content per unit weight compared to pentahydrate, reducing shipping and storage costs per effective unit.

• High Purity: Assay ≥99% suitable for photographic and analytical applications requiring consistent reducing power.

• Stable Supply: Reliable production capacity supporting both sample trials and bulk orders.

• Full Documentation: COA and MSDS available upon request.

Packaging & Storage

• Standard Packaging: 25 kg / 50 kg / 1000 kg in PP woven bags or fiber drums, or customized packaging upon request .

• Storage Conditions: Store in a tightly closed container in a cool, dry place, protected from light and moisture. Avoid contact with strong acids and oxidizing agents.

• Shelf Life: 12–24 months under proper storage conditions.