Is Direct Red 81 vegetarian?
Direct Red 81
Vegetarian
Vegetarian
Vegan
Vegan
Sirius Red 4B, also known as Chlorantine Fast Red 5B or Direct Red 81, is a synthetic azo dye used in histological staining applications. It is listed in the Colour Index as CI 28160.
| Also known as | Chlorantine Fast Red 5B, Direct Red 81, Disodium 7-benzamido-4-hydroxy-3-[[4-[(4-sulphonatophenyl)azo]phenyl]azo]naphthalene-2-sulphonate (CI 28160) |
|---|---|
| INCI name | Direct Red 81 |
| CAS number | 2610-11-9 |
| EC number | 220-028-9 |
| CI number | CI 28160 |
| CosIng ID | 33568 |
| Last reviewed | 3 June 2026 |
An ingredient is considered vegetarian if it avoids components derived from killing an animal.
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