Database/Colorant/CI 73015
Mostly petroleum · ISO 16128

Is CI 73015 natural?

Mostly not. Sulfonate groups come from mineral sulfuric acid and sodium is a mineral counter-ion, so both count as natural origin, exactly as they do for the other sulfonated colour index dyes on this site. Only the indigoid aromatic chromophore, built from synthetic intermediates, is petrochemical.

INCI nameCI 73015
CAS860-22-0
FormulaC16H8N2Na2O8S2 · 466.4 Da
FunctionColorant
FeedstockManufactured synthetically from aromatic precursors to meet colour…

How we scored it

Indigo carmine is C16H8N2Na2O8S2, 466.35 Da. Natural origin is the two sulfonate groups (2 x SO3 = 160.12 Da) plus the two sodium counter-ions (45.98 Da) = 206.10 Da, against a petrochemical indigoid core of 260.25 Da. So 206.10/466.35 = 0.44.
What counts. ISO 16128-2 scores the atoms that remain in the final ingredient. Reagents, solvents, catalysts and protecting groups used during manufacture leave no mass behind and are not counted.

Where it comes from

Manufactured synthetically from aromatic precursors to meet colour index purity and heavy-metal specifications, then sulfonated and isolated as the disodium salt. Plant indigo extraction is not used for cosmetic-grade material of this type.

In plain English

A synthetic blue-purple colorant chemically related to natural indigo dye, but manufactured from man-made chemical building blocks to meet purity standards. Used to add colour to cosmetic products.

CosIng definition: CI 73015 is classed chemically as an indigoid colour. It conforms to the formula:

Natural alternatives with the same function

Aluminum Powder 100% natural origin

Finely powdered aluminum metal used to add shimmer or color to cosmetics. It comes from refining bauxite ore,…

 Aluminum Stearate 100% natural origin

An aluminium salt of stearic acid, a fatty acid from vegetable or animal fat. Used to prevent caking,…

 Anthocyanins 100% natural origin

A natural colorant that gives products red, purple or blue tones. It is recovered from grape skins or…

 Calcium Ferrite 100% natural origin

A mineral pigment made of calcium and iron oxide, used as a colourant in cosmetics. It is produced…

 Calcium Stearate 100% natural origin

The calcium salt of stearic acid, a fatty acid usually from vegetable oils. Used as an anti-caking, thickening…

 Caramel 100% natural origin

A colouring and fragrance ingredient made by heating sugar, sucrose or glucose, until it browns. It comes from…

Structure

2D structure of CI 73015

disodium;2-(3-hydroxy-5-sulfonato-1H-indol-2-yl)-3-oxoindole-5-sulfonate

PubChem CID 2723854 ↗

References

  1. 1ISO 16128-1:2016 and ISO 16128-2:2017 — Guidelines on technical definitions and criteria for natural and organic cosmetic ingredients and products. ISO, Geneva.
  2. 2CI 73015. PubChem CID 2723854. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3CI 73015. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4CI 73015. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=CI%2073015