Molekula
Potassium thiosulfate
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Potassium thiosulfate is an inorganic compound with the chemical formula K2O3S2, primarily used as a reducing agent, antichlor in water treatment, and in photography for fixing developed films. It’s also employed in chemical analysis, gold extraction, and as a liquid fertilizer supplying potassium and sulfur to crops. This chemical has a CAS number of 10294-66-3, a molecular weight of 190.3248, and requires ambient storage conditions. It carries no signal word under standard hazard classifications. Molekula supplies potassium thiosulfate from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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25 g — £59.00 per pack ex VAT · £70.80 inc. VAT
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | White crystal powder |
| Water | ≤8.5% |
| Assay | ≥98% |
| K2O | ≥48% |
| Iron (Fe) | ≤40ppm |
| Sulphur (S) | ≥30.5% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Identification
| Property | Value |
|---|---|
| SKU | 90022936 |
| CAS Number | 10294-66-3 |
| IUPAC Name | dipotassium;dioxido-oxo-sulfanylidene-lambda6-sulfane |
| EC Number | 233-666-8 |
| Molecular Formula | K2O3S2 |
| Molecular Weight | 190.3248 |
| Exact Mass | 189.8563 |
| SMILES | [O-]S(=O)(=S)[O-].[K+].[K+] |
| InChIKey | FGRVOLIFQGXPCT-UHFFFAOYSA-L |
| InChI | InChI=1S/2K.H2O3S2/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2 |
| PubChem CID | 61501 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 28323050 |
| Tariff Code | 2832300000 |
Safety & GHS
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Health Hazard
GHS07
Hazard statements
- H315 Causes skin irritation
- H319 Causes serious eye irritation
Precautionary statements
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P302+352 IF ON SKIN: Wash with soap and water
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- Dipotassium sulfurothioate
- DIPOTASSIUM THIOSULFATE
- dipotassium;dioxido-oxo-sulfanylidene-lambda6-sulfane
- FGRVOLIFQGXPCT-UHFFFAOYSA-L
- Potassium Hyposulfite
- potassium sulfothioate
- POTASSIUM THIOSULFATE ANHYDROUS
- Potassium thiosulphate
- Thiosulfuric acid (H2S2O3), dipotassium salt
- Thiosulfuric Acid, Dipotassium Salt
Frequently asked questions
What is potassium thiosulfate commonly used for?
Potassium thiosulfate is primarily used in photography as a fixer to remove unexposed silver halide from photographic emulsions, as well as in water treatment, chemical analysis, and as a reducing agent in various industrial processes.
What is the chemical formula and molecular weight of potassium thiosulfate?
The chemical formula is K₂O₃S₂ (or K₂S₂O₃), and the molecular weight is 190.3248 g/mol.
How should potassium thiosulfate be stored?
Store at ambient temperature in a cool, dry place, away from incompatible substances like strong oxidizers. Ensure containers are tightly sealed.
What grades of potassium thiosulfate does Molekula supply?
Molekula supplies technical grade potassium thiosulfate, suitable for industrial and laboratory applications requiring high purity and consistency.
Can Molekula supply potassium thiosulfate in bulk quantities?
Yes, Molekula can provide potassium thiosulfate in bulk quantities tailored to your specific requirements—please contact us for pricing and availability.
What documentation comes with a potassium thiosulfate order?
Each order includes a Certificate of Analysis (CoA), Material Safety Data Sheet (MSDS), and a packing list detailing product specifications and batch information.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.