Database/Hair Dyeing/Basic Blue 9
Mostly petroleum · ISO 16128

Is Basic Blue 9 natural?

Mostly not. Synthetic phenothiazine hair dye supplied as a salt. Only the chloride counter-ion counts as natural origin under the site's mineral counter-ion convention; every carbon in the coloured cation is petrochemical.

INCI nameBasic Blue 9
CAS61-73-4
FormulaC16H18ClN3S · 319.9 Da
FunctionHair Dyeing
FeedstockPetrochemical aromatic amines and couplers assembled into the…

How we scored it

Basic Blue 9 (methylene blue) C16H18ClN3S 319.9 Da: chloride counter-ion Cl 35.5 Da is mineral-derived (natural); the phenothiazine dye cation 284.4 Da is built entirely from petrochemical aromatic intermediates → 35.5/319.9 = 0.11.
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

Petrochemical aromatic amines and couplers assembled into the dye cation, isolated as its salt.

In plain English

A deep blue synthetic dye (Methylene Blue) used in hair and cosmetic colourants, made entirely from petroleum-derived aromatic chemicals.

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Structure

2D structure of Basic Blue 9

[7-(dimethylamino)phenothiazin-3-ylidene]-dimethylazanium chloride

PubChem CID 6099 ↗

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. 2Basic Blue 9. PubChem CID 6099. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3BASIC BLUE 9. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4BASIC BLUE 9. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=BASIC%20BLUE%209