Invented by Nouryon, ferrocyanide is the standard anti-caking agent for salt since the 1950’s

Salt is hygroscopic above 75 % relative humidity. Therefore, salt crystals can absorb enough moisture during storage to form a brine film on their surfaces. Subsequent water evaporation due to changes in temperature or air humidity causes recrystallization of the brine film and the crystals bond together. Caking hampers the handling of salt, in terms of loading/unloading and transport.

Ferrocyanide or Yellow Prussiate of Soda (YPS) perfectly matches the salt crystal structure and prevents the salt crystals from bonding together.