Product Overview & China Production Capacity
Sodium Thiosulfate (Na₂S₂O₃, CAS 7772-98-7 anhydrous / 10102-17-7 pentahydrate, MW 158.11 anhydrous / 248.18 pentahydrate) is a versatile reducing agent used in pharmaceutical applications as a cyanide antidote, in photographic fixing, water dechlorination, and as an analytical reagent. Chinese manufacturers produce both anhydrous and pentahydrate forms at large-scale facilities in Jiangsu, Shandong, and Henan provinces, with combined annual capacity exceeding 200,000 metric tons. This production scale supports manufacturer-direct supply of pharmaceutical and technical grades.
In clinical medicine, injectable sodium thiosulfate serves as a life-saving antidote for cyanide poisoning and as a nephroprotectant during cisplatin chemotherapy. It is also used as an antifungal agent in topical preparations and as a reducing agent in pharmaceutical synthesis. Industrial applications include photographic fixing (hypo), dechlorination of water treatment effluents, and gold extraction. Chinese producers offer multiple purity grades from technical to injectable-grade quality with appropriate quality documentation.
Manufacturing Standards & Quality Assurance
Pharma-grade production facilities maintain ISO 9001:2015, and cquality certifications. Quality testing includes assay (iodometric titration), pH, clarity and color of solution, chloride, sulfate, sulfide, calcium, heavy metals, arsenic, and bacterial endotoxin testing for injectable grades. Products comply with USP/NF, EP, and ChP monograph requirements.
Manufacturing involves reaction of sodium sulfite with elemental sulfur or reaction of sodium hydroxide with sulfur dioxide and sulfur under controlled conditions. Multi-stage crystallization and recrystallization produce high-purity pentahydrate crystals. Anhydrous grade is obtained through carefully controlled dehydration. Process monitoring ensures consistent crystal quality and purity across batches.
Technical Specifications
| Parameter | Specification |
|---|---|
| CAS Number | 7772-98-7 (anhydrous) / 10102-17-7 (pentahydrate) |
| Molecular Formula | Na₂S₂O₃·5H₂O (pentahydrate) |
| Molecular Weight | 248.18 g/mol (pentahydrate) |
| Appearance | Colorless transparent crystals |
| Assay | 99.0–101.0% |
| pH (10% aqueous) | 6.0–8.4 |
| Clarity of Solution | Clear |
| Chloride | ≤0.02% |
| Heavy Metals (Pb) | ≤10 ppm |
| Pharmacopoeial Compliance | USP/NF, EP, ChP |
Packaging & Export Logistics
Sodium thiosulfate pentahydrate is packed in 25 kg or 50 kg PE-lined woven bags or fiber drums, palletized for container loading. Bulk 1,000 kg FIBCs are available for industrial orders. Lead time is 7–12 business days. FOB shipment from Shanghai, Qingdao, or Lianyungang; CIF and DDP terms available.
Non-hazardous classification facilitates straightforward international shipping. Documentation includes CoA, SDS, and commercial shipping paperwork.
China Supply Advantage
Direct sodium thiosulfate from China delivers 30–45% cost savings through efficient sulfur-based chemistry and large-scale crystallization operations. Chinese producers serve pharmaceutical, photographic, water treatment, and mining customers worldwide with consistent quality and responsive supply chain management. Multilingual commercial teams provide quotation, sampling, and technical support services tailored to international customer requirements.