Indigo Carmine
INS No. 132
FD&C Blue No. 2
E 132
CI No. 73015
CAS 860-22-0
Indigotine occurs as a blue-brown to red-brown powder or as granule. It is an indigoid dye, consisting of a mixture of disodium 3,3′-dioxo-[delta2,2′-biindoline]-5,5′-disulfonate (the principal component), disodium 3,3′-dioxo-[delta2,2′-biindoline]-5,7′-disulfonate (an isomer) and subsidiary coloring matters and may be converted to the corresponding aluminum lake.
Indigotine is distinguished by its rich royal blue color, and can be used for coloring foods and drugs, including dietary supplements, blueberry bagels, breakfast cereals, cakes and cupcakes, candies including chocolate, chewing gum, dairy products, decorations for baking, frozen treats, and sauces and seasonings.
US FDA
Commission Regulation (EU) No 231/2012
Indigotine (INS No. 132) is added to foods and beverages at concentrations up to a maximum permitted level (MPL) as adopted by the Codex Alimentarius Commission. There are more than 50 food categories for which MPLs for indigotine have been adopted in the General Standard for Food Additives.
Evaluation of certain food additives: eighty-sixth report of the Joint FAO/WHO Expert Committee on Food Additives. Geneva: World Health Organization and Food and Agriculture Organization of the United Nations; 2019 (WHO technical report series; no. 1014). Available online
EFSA ANS Panel (2014) Scientific opinion on the re-evaluation of Indigo Carmine (E 132) as a food additive. EFSA Journal, 12(7), 3768 [51 pp]. Available online