Database/Hair Dyeing/Solvent Red 23
100% petroleum · ISO 16128

Is Solvent Red 23 natural?

No. A synthetic azo dye made by coupling petrochemical aromatic amines with naphthol; no natural-origin building blocks.

INCI nameSolvent Red 23
CAS85-86-9
FormulaC22H16N4O · 352.4 Da
FunctionHair Dyeing
FeedstockSolvent Red 23 is manufactured by diazotisation and…

How we scored it

Disazo naphthol dye built from petrochemical aniline and naphthol aromatics → 0/total = 0.0
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

Solvent Red 23 is manufactured by diazotisation and coupling of petrochemical aromatic amines and naphthol. There is no natural-origin production route.

In plain English

A synthetic red dye used to colour hair. It is produced entirely from man-made aromatic chemicals and has no plant or mineral source.

CosIng definition: Solvent Red 23 is classed chemically as a disazo colour. It conforms to the formula:

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Structure

2D structure of Solvent Red 23

1-[(4-phenyldiazenylphenyl)diazenyl]naphthalen-2-ol

PubChem CID 62331 ↗

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. 2Solvent Red 23. PubChem CID 62331. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3SOLVENT RED 23. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4SOLVENT RED 23. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=SOLVENT%20RED%2023