Description

Sodium Thiosulfate is an essential inorganic salt with versatile reducing and complexing properties. It is a critical reagent in numerous industrial processes, valued for its ability to neutralize chlorine, reduce compounds, and act as a source of sulfur. Key industries that rely on this compound include water treatment, photographic processing, leather manufacturing, and gold extraction.

Application

• Water Treatment: As a dechlorinating agent to neutralize excess chlorine and chloramines in municipal and industrial wastewater.
• Photographic Industry: Serves as a fixing agent ("hypo") to dissolve unexposed silver halides from photographic films and papers.
• Leather Tanning: Used to remove residual chlorine after the bleaching process and as a reducing agent in chrome tanning.
• Mining & Metallurgy: A key lixiviant in the cyanide leaching process for gold and silver extraction.
• Analytical Chemistry: Employed in iodometric titrations as a standardized reducing agent for quantitative analysis.
• Medical & Pharmaceutical: Used as an antidote for cyanide poisoning and in certain topical treatments.
• Pulp & Paper: Applied in bleaching sequences to quench oxidative bleaching agents and prevent cellulose degradation.
• Textile Processing: Used to remove chlorine after bleaching and as a reducing agent in dyeing processes.

Basic Information

Item	Detail
Product Name	Sodium Thiosulfate
CAS No.	7772-98-7
Molecular Formula	Na2S2O3
Molecular Weight	158.11 g/mol (anhydrous)
Synonyms	Sodium Hyposulfite; Hypo; Antichlor; Disodium Thiosulfate; Sodium Thiosulphate; Thiosulfuric Acid Disodium Salt; Fixer; "Hypo" Salt
EINECS	231-867-5

Quality Control

Our Sodium Thiosulfate is manufactured under a stringent quality management system. Each batch undergoes comprehensive analytical testing to ensure it meets precise specifications for purity, assay, and impurity profiles. Certificates of Analysis (COA) confirming compliance with relevant standards such as USP, FCC, or ACS grades are available upon request to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). This product is hygroscopic (moisture-sensitive) and should be kept in original packaging away from moisture sources. Separate from strong acids and oxidizing agents.

Specification

Item	Specification
Appearance	White crystalline powder or granules
Identification (IR)	Conforms
Assay (Na2S2O3)	≥ 99.0%
pH (5% solution)	6.0 - 8.0
Water Insoluble Matter	≤ 0.01%
Sulfate (SO4)	≤ 0.1%
Sulfide (S)	≤ 10 ppm
Heavy Metals (as Pb)	≤ 10 ppm

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.