TCS Industries Limited (China-sourced API supplier) supplies Sodium Thiosulfate CAS 7772-98-7 for pharmaceutical B2B procurement — COA, MSDS, and technical documentation available on request.
> Overview
| Product Name | Sodium Thiosulfate |
|---|---|
| Structural Formula |  |
| CAS Number | 7772-98-7 |
| Molecular Formula | H10Na2O8S2 |
| Molecular Weight | 248.19 g/mol (pentahydrate); 158.11 g/mol (anhydrous) |
| InChIKey | PODWXQQNRWNDGD-UHFFFAOYSA-L |
| SMILES | Available on request where applicable |
| Appearance | Large colourless crystals or white crystalline powder |
| Purity / Grade | By agreed specification and batch COA |
| Storage | Keep tightly closed in a cool, dry, well-ventilated place |
Sodium Thiosulfate (CAS 7772-98-7) is an inorganic sodium salt with the formula Na₂S₂O₃. The pentahydrate (Na₂S₂O₃·5H₂O, CAS 10102-17-7, MW 248.18) is the standard commercial form. Sodium thiosulfate is used as a cyanide antidote in emergency medicine, photographic fixer (hypo), dechlorination agent in water treatment, and reducing agent in analytical chemistry and industrial processing.
TCS Industries Limited, a Hong Kong-based trading and sourcing company, supplies Sodium Thiosulfate in pharmaceutical, photographic, analytical and technical grades for global procurement programs.
> Applications
Cyanide antidote in emergency medicine
Sodium thiosulfate injection (USP, 250 mg/mL) is used as an antidote for cyanide poisoning, administered intravenously in combination with sodium nitrite or hydroxocobalamin. It acts as a sulfur donor for the enzyme rhodanese, which converts cyanide to the less toxic thiocyanate for renal excretion. Pharmaceutical-grade sodium thiosulfate (USP/Ph.Eur.) is required for injectable formulation. Hall et al. (Ann Emerg Med, 2007, 49:806–813) reviewed the clinical pharmacology and dosing of cyanide antidotes including sodium thiosulfate.
Dechlorination and water treatment
Sodium thiosulfate is used to neutralize residual chlorine in treated water, wastewater discharge and swimming pools. The stoichiometry is 1 mol Na₂S₂O₃ per 4 mol Cl₂ (or per 4 mol NaOCl). It is also used in aquaculture to remove chlorine and chloramine from incoming water before fish stocking. Technical-grade material is sufficient for water treatment applications.
> Sourcing & Supply
TCS Industries Limited supports development, qualification and commercial purchasing discussions for Sodium Thiosulfate with buyers in South America, Europe, the United Kingdom, Australia, New Zealand, Mexico and Canada.
- Evaluation and commercial quantities: 25 kg bags for qualification; pallet and bulk for production. Pentahydrate and anhydrous forms in pharmaceutical, photographic, analytical and technical grades.
- Pallet quantities and production campaigns: repeat supply is coordinated against packaging, lead time, annual demand and destination-market import requirements.
> Quality & Documentation
Key specification parameters depend on grade. Pharmaceutical grade (USP/Ph.Eur.): assay (≥99.0% Na₂S₂O₃ on anhydrous basis), heavy metals, arsenic, selenium, sulfate, sulfide, calcium, iron, clarity and colour of solution. Photographic/analytical grade: assay (≥99.5%), insolubles, pH, sulfate, sulfide. Technical grade: assay (≥98%), moisture, pH, clarity. COA and MSDS are standard for all grades.
> Packaging
Sodium Thiosulfate pentahydrate effloresces in dry air above 48 °C and should be stored in sealed containers at controlled room temperature. Standard packaging includes 25 kg fibre drums or paper bags (pharma/analytical grade), 25 kg or 50 kg woven PP bags (technical grade), and palletized shrink-wrapped units. Store away from oxidizing agents. Labels and documents are checked before dispatch.
> Pricing & MOQ
Pricing is quoted by specification, packaging and destination. Common commercial discussions use 25 kg bag/drum formats, pallet quantities and production-campaign planning; smaller samples may be reviewed for qualified formulation teams.
> Regulatory & Compounding Context
Sodium Thiosulfate is monographed in USP, BP and Ph.Eur. (Natrii thiosulfas). It is on the WHO Model List of Essential Medicines as a cyanide antidote. Listed in the FDA IID. REACH-registered in the EU. Not classified as dangerous goods for transport (non-hazardous). Buyers should specify grade (pharmaceutical, photographic, analytical, technical) and hydration form (pentahydrate or anhydrous) at inquiry.
> Alias Index
- IUPAC: Disodium thiosulfate
- CAS Number: 7772-98-7 (anhydrous); 10102-17-7 (pentahydrate)
- Formula: Na₂S₂O₃ (anhydrous, MW 158.11); Na₂S₂O₃·5H₂O (pentahydrate, MW 248.18)
- Common names: Hypo, Sodium hyposulfite (deprecated), Antichlor
- Pharmacopoeial names: Natrii thiosulfas (Ph.Eur.), Sodium Thiosulfate (USP)
- InChIKey: AKHNMLFCWUSKQB-UHFFFAOYSA-L
- Commercial request terms: sodium thiosulfate USP, hypo fixer, Na2S2O3 injection grade, dechlorination agent, cyanide antidote, TCS Industries Limited
> FAQ
What grades of Sodium Thiosulfate does TCS supply?
TCS sources pharmaceutical grade (USP/Ph.Eur.), photographic grade, analytical (ACS) grade and technical grade. Pentahydrate is the standard commercial form. Anhydrous form is available on request. Specify the intended application and required standard at inquiry.
What documents are available for Sodium Thiosulfate orders?
COA and MSDS are standard for commercial discussions. COO, packing list, invoice and other import-support documents can be arranged according to order scope.
Can TCS Industries Limited support Sodium Thiosulfate supply to South America?
Yes. We support B2B buyers in Argentina, Colombia, Chile, Peru, Ecuador, Uruguay, Bolivia, Brazil, Paraguay, Venezuela, Guyana and Suriname, subject to route and document review.
Do you support Europe, the United Kingdom, Australia, New Zealand, Mexico and Canada?
Yes. These destinations can be reviewed for project supply, import documents, packaging and logistics planning before quotation.
Is Sodium Thiosulfate on the WHO Essential Medicines List?
Yes. Sodium Thiosulfate injection is on the WHO Model List of Essential Medicines as a cyanide antidote. It is used with sodium nitrite or hydroxocobalamin in the emergency treatment of cyanide poisoning. Pharmaceutical-grade material is required for injectable formulation.
How does Sodium Thiosulfate neutralize chlorine in water?
Sodium thiosulfate reduces hypochlorous acid and hypochlorite to chloride. One mole of Na₂S₂O₃ neutralizes four moles of chlorine. It is used for dechlorination of treated wastewater, swimming pool water, and aquaculture water supply systems.
Can you arrange samples before commercial purchasing?
Samples or evaluation quantities may be reviewed for qualified buyers after target specification, application and destination-market requirements are clarified.
How is Sodium Thiosulfate packaged for export?
Packaging is confirmed by quantity and material properties. Typical options include foil bags, HDPE containers, fibre drums, 25 kg bags or palletized export packaging.
Can buyer-defined specifications be reviewed?
Yes. Send the specification, methods, impurity limits and required documents. TCS can review feasibility before confirming quotation and lead time.
What payment terms are normally used?
Standard payment is 100% T/T before dispatch unless a different arrangement has been approved for an established commercial account.
What lead time should buyers expect?
Lead time depends on stock, batch size, document scope and destination. Available stock can move faster; made-to-order or pallet programs require longer planning.
Is Sodium Thiosulfate classified as dangerous goods?
No. Sodium Thiosulfate (both pentahydrate and anhydrous) is not classified as dangerous goods under ADR/IMDG/DOT regulations. Standard commercial packaging and transport procedures apply. However, it should be stored away from strong oxidizing agents.
Last reviewed: June 2026
Evaluation and research orders (≤10 kg) are shipped with COA, MSDS, and certificate of origin. Bulk commercial orders (>10 kg) qualify for volume pricing with a full technical documentation package available on request.
> Request a Quote
If your team already has a target application, estimated quantity, destination market, or documentation requirements, send those details so the commercial response can be prepared more efficiently.