Potassium ferrocyanide
General Product Information
| Article | Potassium ferrocyanide |
| Synonyms |
E536, Potassium hexacyanidoferrate(II), (Yellow) Prussiate of Potash, Potassium hexacyanoferrate (II) trihydrate, Tetrapotassium ferrocyanide trihydrate, Ferrate hexacyano tetrapotassium trihydrate, Potassium ferrocyanide trihydrate |
| CAS No. | 14459-95-1 |
| EEG No. | – |
| EINECS No. | 237-722-2 |
| IMO | – |
| Tariff Code | 28372000 |
| UN No. | – |
| VLG/ADR | – |
Description
Potassium ferrocyanide, also known as Yellow Potash, is an inorganic salt. It is a pale yellow crystalline powder used primarily as an anti-caking agent in the food industry, but it also has wide industrial applications in the chemical, metallurgical and water treatment sectors, among others. Despite the presence of cyanide ions, Potassium ferrocyanide is not toxic under normal conditions, as the cyanide complex is strongly bound to iron.
Characteristics
- Odor: Odorless
- Hygroscopic: –
- Color: Light yellow.
- Grade: Food.
- Solubility: Highly soluble in water, insoluble in alcohol.
- Taste: –
- Shape: Crystals or powder.
Physical & Chemical Properties
| Chemical Structure | K4[Fe(CN)6]-3H₂O |
| Molar Weight | 422.4 g/mol |
| Melting Point | Approx. 60 °C (loss of crystal water) |
| Boiling Point | – |
| Density | 1.85 g/cm³ |
| Refractive Index | – |
| pH | Approx. 6-7 (on 1% solution). |
Interessing Links
- Codex Alimentarius (FAO/WHO) – Guidelines and standards for food additives and ingredients.
- European Chemicals Agency (ECHA) – For chemical information and regulations.
- European Food Information Council (EFIC)
- European Food Safety Authority (EFSA) – Information on the safety and uses of food additives and ingredients.
- PubChem – Potassium Ferrocyanide Trihydrate – Chemical information by the National Library of Medicine der National Center for Biotechnology Information (NIH-NCBI).
- Wikipedia – Potassium ferrocyanide
Applications
Potassium ferrocyanide is applied in various ways, for instance:
1. Food Industry
Used as an anti-caking agent in table salt (as food additive E536), especially to prevent clumping in humid environments.
2. Laboratory Applications
Reagent in analytical chemistry, for example at the detection of iron(III).
3. Water Treatment
Complexing agent for heavy metals, for example at industrial wastewater treatment.
4. Pigment Production
Raw material for the preparation of blue pigments such as Prussian blue.
5. Metal Industry
Used in galvanic baths, surface treatment of metals, and in some cases at steel production.