Database/Hair Dyeing/Acid Orange 24
Mostly petroleum · ISO 16128

Is Acid Orange 24 natural?

Mostly not. The sodium sulfonate group counts as natural per the mineral-salt rule; the aromatic hydrazone dye backbone is wholly petrochemical.

INCI nameAcid Orange 24
CAS1320-07-6
FormulaC20H17N4NaO5S · 448.4 Da
FunctionHair Dyeing
FeedstockA fully synthetic azo/hydrazone dye built from petrochemical…

How we scored it

C20H17N4NaO5S, 448.4 Da: Na+SO3 (natural salt fragment, 103.1 Da) + synthetic azo/hydrazone dye backbone (petrochemical, 345.3 Da); 103.1/448.4=0.23.
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

A fully synthetic azo/hydrazone dye built from petrochemical aromatic precursors, isolated as its sodium sulfonate salt. No natural-origin route exists.

In plain English

A synthetic dye used to colour hair. It is built from petroleum-derived aromatic chemicals; only the small sodium-sulfonate salt portion counts as natural by this site's mineral-salt convention.

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Structure

2D structure of Acid Orange 24

sodium 4-[(2Z)-2-[(5E)-5-[(2,4-dimethylphenyl)hydrazinylidene]-4,6-dioxocyclohex-2-en-1-ylidene]hydrazinyl]benzenesulfonate

PubChem CID 23675104 ↗

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 Orange 24. PubChem CID 23675104. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3ACID ORANGE 24. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4ACID ORANGE 24. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=ACID%20ORANGE%2024