Calcium ferrocyanide

Calcium ferrocyanide is an inorganic compound with the formula Ca₂[Fe(CN)₆]. It is the Ca²⁺ salt of [Fe(CN)₆]^4-, ferrocyanide complex ion. It is insoluble in water, acids, and organic solvents.^[1] A yellow solid, it is used as a precursor to the pigment Prussian blue.^[2]

Calcium ferrocyanide

Names
Other names Dicalcium hexakis(cyano-κC)ferrate(4-)
Identifiers
CAS Number	13821-08-4
3D model (JSmol)	Interactive image
ChemSpider	146050
ECHA InfoCard	100.034.085
EC Number	237-508-9
E number	E538 (acidity regulators, ...)
PubChem CID	166920
UNII	906D36VLZG
CompTox Dashboard (EPA)	DTXSID80930018
InChI InChI=1S/6CN.2Ca.Fe/c6*1-2;;;/q6*-1;3*+2 Key: BAZQCHGUTMBXBU-UHFFFAOYSA-N
SMILES [C-]#N.[C-]#N.[C-]#N.[C-]#N.[C-]#N.[C-]#N.[Ca+2].[Ca+2].[Fe+2]
Properties
Chemical formula	C6Ca2FeN6
Molar mass	292.109 g·mol−1
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H312, H315, H319, H332, H335
Precautionary statements	P261, P280, P301+P312, P302+P352, P304+P340, P305+P351+P338, P332+P313
NFPA 704 (fire diamond)	0 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Safety

It was listed in 2012 by the EU as a "Food Improvement Agent".

In the EU, ferrocyanides (E 535–538) were, as of 2018, solely authorised in two food categories as salt substitutes. Kidneys are the organ for ferrocyanide toxicity.^[3]