contact for fd&c red 40fd&c red 40 by Standardcon

Indigo Carmine

A Royal blue synthetic coal tar dye, normally produced by a synthesis of indoxyl by fusion of sodium phenylglycinate in a mixture of caustic soda and sodamide.

This process was introduced following the discovery of the chemical structure of indigo by the Prussian research chemist J F W Adolf von Baeyer in 1883 and was in regular use by 1890. Very little natural indigo from either Isatis tinctoria or Indigofera has been produced commercially since the turn of the century.

C.I. No.  73015 
FD&C No. Blue 2
E.E.C No.    E 132
C.I. Food Colour No. Blue 1
C.A.S No.          860-22-0
Chemical Name Disodium Slat of Indigotin 5,5-disulphonic acid


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