Database/Hair Dyeing/Basic Red 51
Mostly petroleum · ISO 16128

Is Basic Red 51 natural?

Mostly not. A synthetic direct hair dye; only its chloride counter-ion is of mineral origin.

INCI nameBasic Red 51
CAS77061-58-6
FormulaC13H18ClN5 · 279.77 Da
FunctionHair Dyeing
FeedstockPetrochemical aromatic amines and azo intermediates, isolated as…

How we scored it

Basic Red 51 C13H18ClN5 279.8 Da is a synthetic dye cation with a chloride counter-ion. The organic cation is petrochemical (aromatic amine / azo chemistry); the chloride 35.45 Da counts as natural mineral origin by this site's convention. 35.45/279.8 = 0.13.
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 azo intermediates, isolated as the hydrochloride / chloride salt.

In plain English

A synthetic red dye used in semi-permanent hair color. It's built from petroleum-derived aromatic and imidazole chemicals; a small salt component's natural status is uncertain, so this one needs a closer look.

Natural alternatives with the same function

Beta Vulgaris Root Powder 100% natural origin

A powder made by drying and grinding sugar beet root. Used as a natural colorant for hair dye…

 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 Basic Red 51

4-[(1,3-dimethylimidazol-1-ium-2-yl)diazenyl]-N,N-dimethylaniline chloride

PubChem CID 166491 ↗

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 Red 51. PubChem CID 166491. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3BASIC RED 51. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4BASIC RED 51. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=BASIC%20RED%2051