Pigments & Colorants
REACH
Indigo carmine
CAS Number
860-22-0
EC Number
212-728-8
E Number
E132
What is Indigo carmine?
Indigo carmine (CAS 860-22-0), also known by its food additive designation E132, is a blue synthetic dye derived from indigo. Sodium indigotindisulfonate is the recognized chemical name.
Where is Indigo carmine used?
- Food manufacturing: blue and green shades in confectionery, beverages, and dairy products, often with yellow dyes
- Pharmaceutical: tablet coating colorant and diagnostic agent in urological procedures
- Personal care: colors bath preparations and hair rinses
- Textile and paper: direct dye for cellulosic substrates in dyebath applications
- It functions as a colorant across food, pharmaceutical, cosmetic, and industrial applications.
Good to know: Purity specifications and dye content requirements vary by grade; buyers should confirm compliance documentation against their target application.
Other Names (Synonyms)
Sodium indigotindisulfonate|Sodium indigo-5,5'-bisulfonate|Sodium 5,5'-indigotindisulfonate|Indigotin-5,5'-disulfonic acid disodium salt|FD&C Blue No. 2|FD and C Blue No. 2|E 132|Disodium indigo-5,5-disulfonate|E132
What are the physical properties of Indigo carmine?
Melting Point 300 °C
Density 1.01 g/mL at 20 °C
Appearance purple powder
Color Very dark blue to purple
Odor Light odour
Form Powder/Solid
Water Solubility 1 g/100 mL (25 ºC)
Refractive Index n20/D 1.335
pH 7 (10g/l, H2O, 20℃)
Log P -3.57
Which trade and regulatory codes apply to Indigo carmine?
HS Code 32041200
Storage Class 11 - Combustible Solids
WGK (Germany) 3