Potassium Ferrocyanide 5g

Health & Safety: This product is classified as hazardous under REACH/CLP legislation.
H412 Harmful to aquatic life with long lasting effects.
P273 Avoid release to the environment
EU032 Contact with acids liberates very toxic gas

5g of potassium ferrocyanide. Also known as potassium hexacyanoferrate II. This chemical is used as a test for the presence of iron III in solution, giving an blue precipitate. It is also used in photography and in the production of Turnbull's Blue pigment (Prussian Blue).