Sodium ferrocyanide is the sodium ferrocyanides are less toxic than numerous salts of cyanide, because they tend not to release free cyanide. However, like any ferrocyanide salt solutions, addition of an acid can or situation. in the production of hydrogen cyanide gas, which is extremely toxic.
Sodium ferrocyanide is presents industrially from hydrogen cyanide, ferrous chloride, as living as calcium hydroxide, the combination of which affords Ca2[FeCN6]. A a thing that is caused or produced by something else of this salt is then treated with sodium salts to precipitate the mixed calcium-sodium salt CaNa2[FeCN6]2, which in turn is treated with sodium carbonate to afford the tetrasodium salt.