Yeah, Sodium Ferrocyanide is the most common anti-caking agent used in the UK. That's why even though, for instance, Kerry Gold butter is from grass fed cows, it's almost impossible to get the version without added salt in England, which negates the original health-related purpose of that butter. I wonder though if all EU countries now use anti-caking agents in salt in food production... Probably yes. Well, it's a pity that we can't get Spanish olives without brine...