Database/Hair Dyeing/Acid Blue 74
Mostly petroleum · ISO 16128

Is Acid Blue 74 natural?

Mostly not. Indigo carmine's bis-indole backbone is made from petrochemical aniline; the sodium and sulfonate groups are mineral.

INCI nameAcid Blue 74
CAS860-22-0
FormulaC16H8N2Na2O8S2 · 466.4 Da
FunctionHair Dyeing
FeedstockManufactured by sulfonating synthetic indigo, itself made from…

How we scored it

MW 466.4; Na2 (45.98)+2xSO3 (160.1) mineral/natural=206.1 Da; bis-indole indigotin core (260.3 Da) synthetic. 206.1/466.4=0.442->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 by sulfonating synthetic indigo, itself made from petrochemical aniline derivatives rather than extracted from the indigo plant. Only the sodium counter-ions and sulfonate groups are mineral in origin.

In plain English

Indigo carmine, a synthetic blue dye used to colour hair-dye products. It is made from petrochemical aromatic chemicals, with sodium and sulfonate groups added during manufacture.

Natural alternatives with the same function

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 Epicatechin 100% natural origin

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 Lawsonia Inermis Extract 100% natural origin

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 Pyrogallol 100% natural origin

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Structure

2D structure of Acid Blue 74

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. 2Acid Blue 74. PubChem CID 2723854. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3ACID BLUE 74. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4ACID BLUE 74. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=ACID%20BLUE%2074