Database/Hair Dyeing/HC Blue No. 4
100% petroleum · ISO 16128

Is HC Blue No. 4 natural?

No. HC Blue dyes are synthetic nitroaniline/phenylenediamine hair colorants made from petrochemical aromatic intermediates.

INCI nameHC Blue No. 4
CAS158571-57-4
FunctionHair Dyeing
FeedstockManufactured from petrochemical benzene/aniline-derived intermediates, as with other…

How we scored it

Synthetic nitro-phenylenediamine-type hair dye consistent with other HC dyes; no formula supplied, structure inferred from ingredient class.
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 from petrochemical benzene/aniline-derived intermediates, as with other HC-series direct dyes. No natural-origin route exists.

In plain English

A synthetic dye made from petroleum-derived chemicals, used to add blue color in semi-permanent hair dyes.

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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. 2HC BLUE NO. 4. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  3. 3HC BLUE NO. 4. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=HC%20BLUE%20NO.%204