Is Biebrich Scarlet vegan?

Biebrich Scarlet

Vegan

Biebrich Scarlet (Acid Red 66) is a synthetic anionic mono-azo dye used in histological trichrome staining (e.g. Lillie's trichrome) and as a textile and paper colorant for wool, silk, and cotton. It was first developed in 1878 by German chemist Rudolf Nietzki at Kalle & Co. in Biebrich, Wiesbaden.

Also known as Acid red 66, Croceine scarlet, Ponceau B
CAS number 4196-99-0
CI number CI 26905
Last reviewed 3 June 2026

Sources

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