Database/Hair Dyeing/Acid Red 92
Mostly petroleum · ISO 16128

Is Acid Red 92 natural?

Mostly not. Brominated/chlorinated fluorescein core is petrochemical; only the two sodium counter-ions count as natural.

INCI nameAcid Red 92
CAS18472-87-2
FormulaC20H2Br4Cl4Na2O5 · 829.6 Da
FunctionHair Dyeing
FeedstockSynthesised from petrochemical resorcinol and phthalic anhydride, then…

How we scored it

Phloxine B disodium salt, MW 829.4 (C20H2Br4Cl4Na2O5); Na2 fragment ~46Da natural (metal ion) / ~783Da halogenated fluorescein petrochemical; 46/829=0.06
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

Synthesised from petrochemical resorcinol and phthalic anhydride, then brominated and chlorinated. No natural production route for this xanthene dye.

In plain English

A bright pink synthetic dye (a halogenated fluorescein) used in hair-dye and lip products, made through industrial aromatic-chemical synthesis.

CosIng definition: Acid Red 92 is classed chemically as a xanthene colour. It conforms to the formula:

Natural alternatives with the same function

Beta Vulgaris Root Powder 100% natural origin

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 Bismuth Citrate 100% natural origin

A salt formed from bismuth metal and citric acid, a natural fermentation-derived fruit acid, used to buffer, chelate…

 Dihydroxyacetone 100% natural origin

The active self-tanning ingredient that reacts with skin's surface proteins to produce a temporary bronze colour; made by…

 Epicatechin 100% natural origin

An antioxidant compound naturally found in tea and cocoa, used in skin, hair and oral care. It's extracted…

 Lawsonia Inermis Extract 100% natural origin

A plant extract from the henna shrub, used to condition hair and skin and add a reddish tint.…

 Pyrogallol 100% natural origin

A hair-dye ingredient traditionally made by heating gallic acid, itself extracted from plant tannins in gallnuts, until it…

Structure

2D structure of Acid Red 92

disodium;2',4',5',7'-tetrabromo-4,5,6,7-tetrachloro-3-oxospiro[2-benzofuran-1,9'-xanthene]-3',6'-diolate

PubChem CID 6433718 ↗

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 Red 92. PubChem CID 6433718. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3ACID RED 92. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4ACID RED 92. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=ACID%20RED%2092