Sodium ferrocyanide (E535)

Sodium ferrocyanide E535 (sometimes called yellow blood salt) is a food-grade emulsifier with excellent chemical properties, which is actively used to improve the safety of a variety of products.

Sodium ferrocyanide (Na₄Fe(CN)₆) is a complex sodium compound containing the group [Fe(CN)₆]₄ . It is a yellowish crystalline solid that is soluble in water but insoluble in alcohol.

Although sodium cyanide contains a cyanide ligand, it is only slightly toxic because the cyanide is closely related to iron. The approved daily dose is 0-0,025 mg/kg body weight. However, the addition of acid, like other ferrocyanide compounds, produces toxic hydrogen cyanide gas.

In the European Union, sodium ferrocyanide is known as chemical additive E535. It is added, for example, to road and table salt as an anti-caking agent. By adding iron, it can be made from pre-blue dye. The substance is a negative ion with the chemical formula Fe(CN)₆. They differ from each other only in booking. Ferrosinide can be converted to ferrocyanide, and vice versa, by a redox reaction.

While there are many toxic cyanides, ferrocyanides are much less toxic because the cyanide group is closely related to iron.

Ferrocyanides having E-code E535 (sodium ferrocyanide), E536 (potassium ferrocyanide) and E538 (calcium ferrocyanide) are used as an anti-caking agent in salt. Even if the substance enters the groundwater, it is not considered harmful because it evaporates under sunlight and in acidic conditions, and disinfection at more than 8,5 pH changes cyanides to harmless cyanides. In Australia and New Zealand, E538 is banned.

The systematic name of ferrocyanide is hexacyanoferrate (II) and hexacyanoferrate (III).

Physical characteristics of E535

Sodium ferrocyanide is a powdery or crystallized substance of yellow or orange color. The emulsifier is insoluble in ethyl alcohol, essential oils and ordinary water. The additive was obtained through chemical gas purification processes. E535 refers to sodium salts, which are obtained by exposing raw materials to hydrocyanic acid. Until recently, this emulsifier was actively used in the food industry, until scientists proved that a large amount of a substance can cause serious damage to the human body.

sodium ferrocyanide and salt

Some commercial grades of salt contain a small amount of sodium ferrocyanide to prevent caking. When the humidity is high, a thin layer of moisture forms on the surface of the salt crystals and part of the salt dissolves in this layer to form brine. If the relative humidity then drops, the water evaporates and the brine solution recrystallizes between the salt crystals, causing them to clump together. Ferrocyanide reduces the salt’s solubility in water, so the salt is less likely to dissolve in the moisture that coats the crystals, which in turn reduces the amount of recrystallization.

Any mention of cyanide evokes images of poisons, so the presence of ferrocyanide in salt sounds scary. That’s why manufacturers would prefer to list it on the label as “yellow soda flakes” – an old-fashioned term first coined in reference to Prussia, the country where it was originally synthesized. However, there is no need to be afraid of this substance because the cyanide in this compound is closely bound to the iron atom and is not released in the body. Even if it were, it would be inappropriate because the amount of salt added is too small to cause any harm. And ferrocyanide itself is extraordinarily non-toxic.

Application

Sodium ferrocyanide is mainly used as an important raw material for pharmaceutical, pigment, assembly, metallurgy and chemical industries. It is applied to the production of iron and potassium silicate, surface corrosion protection for tanning and metal, carburation for carbon steel, iron removal in pharmaceutical production. It is used as an oxidizing agent, food additive, explosive and chemical agent. Also used as an additive to prevent agglomeration in melted snow in winter.

During the mixing period, the wine is treated with a solution of sodium ferrocyanide in combination with fining. This wine is infused for twenty days until clarified, then filtered. The resulting precipitate is disposed of. Before bottling the wine, it checks the amount of E535, heavy metals and Prussian blue. In the finished wine, the content of E535 must be at zero, otherwise the drink will not go on sale.

Release form and storage

Packing: in kraft paper bags/plastic woven bags/plywood drums/cartons 25/50kg net, also can be 500kg/800kg/1000kg in big bags.

Stored in a dry, dark and ventilated place; without mixing with acid.

Permission to use

Application in production is allowed in the following countries: Canada, USA, EU countries, Belarus, Russia. On the territory of Ukraine, there are no data on the permission to use this additive.

When choosing food and other household and medicinal products, it is important to pay attention to the composition, since some manufacturers still use sodium ferrocyanides in their production. And although this emulsifier is safe in moderate dosages, we do not recommend risking your health, since E535 is a toxic additive of chemical origin, and, as you know, such substances cannot benefit the body. Be careful and choose only safe, healthy and wholesome foods.