Fatty acid salts — designated E470 — are the sodium, potassium, calcium, and magnesium salts of edible fatty acids, used as food additives. Made by neutralising fatty acids with the corresponding alkali, they serve as emulsifiers, stabilisers, and anti-caking agents: keeping powdered foods flowing, helping emulsions hold, and preventing sticking in products from cake mixes to chewing gum. They are among the most innocuous additives in the code — essentially the salts of the same fatty acids food already contains, and chemically close to soap, which is exactly what they are in a food-grade form. Their E number groups them with the fatty-acid esters used for the same purposes. Shoppers scanning labels for alarming additives can pass E470 by: it is functionality borrowed straight from the chemistry of fats themselves.