Is Patent Blue V vegan?

Patent Blue V

Vegan

Patent Blue V is a synthetic triphenylmethane azo dye used as a blue food colourant and in cosmetics. It is produced via chemical synthesis from petroleum-derived precursors.

Also known as Acid Blue 3, CI42051, Erioglaucine disodium salt, Food Blue 5, Sky Blue, Sulphan Blue
E number E131
CAS number 3536-49-0
CI number CI 42051
Last reviewed 22 April 2026

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