Is Acid Red 66 vegan?
Acid Red 66
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, Biebrich Scarlet, Croceine scarlet, Ponceau B |
|---|---|
| CAS number | 4196-99-0 |
| CI number | CI 26905 |
| Last reviewed | 3 June 2026 |
An ingredient is considered vegan if it contains no animal-derived components at any point in its production.
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