E538: Calcium Ferrocyanide
Main role: preventing salt clumping
Also listed as: calcium hexacyanoferrate(II)
What is E538 (Calcium Ferrocyanide)?
Calcium ferrocyanide is another member of the specified ferrocyanide group used for salt anticaking. Its calcium counterion distinguishes it from sodium and potassium ferrocyanide.
What does it do in food?
Its main role is preventing salt clumping. Mineral ingredients can adjust acidity, firm a food, or keep powders flowing. A technical mineral ingredient does not establish a nutritional dose; use the nutrition declaration to assess amounts per serving.
Food and formulation examples
- Table salt
- Salt-based ingredients
These examples describe formulation roles, not a list of unrestricted legal uses. Availability and permitted applications differ by country and food category.
Label names and ingredient questions
Look for E538, E 538, or the ingredient name. Related names and label terms include calcium hexacyanoferrate(II). A family code can cover more than one specified form; check the full declaration when the distinction matters.
The calcium component does not turn this anticaking additive into a nutritional calcium source. Its purpose is powder handling at restricted use levels.
Is E538 safe?
EFSA’s 2018 review found no safety concern at the authorized uses and use levels assessed. EFSA ferrocyanides assessment (2018).
A label identifies the ingredient but usually not its concentration. Calculating daily intake requires the amount in the food and the quantities eaten.
Authorization and conditions of use
The Great Britain food additive register lists E538 as Calcium ferrocyanide. This is an entry subject to its stated conditions, not unrestricted permission for every food. The record links to the applicable authorization terms. For an EU product, use the European Commission food additive database to check the relevant food category and limits. Other countries may use different names or rules.