Database/Film Forming/Polyquaternium-51
Mostly petroleum · ISO 16128

Is Polyquaternium-51 natural?

Mostly not. Only the phosphate group is mineral-derived; the methacrylate backbone, amine linker and butyl group are all petrochemical.

INCI namePolyquaternium-51
CAS125275-25-4
FunctionFilm Forming · Skin Conditioning
FeedstockA synthetic copolymer built from petrochemical methacrylic acid,…

How we scored it

Copolymer of phosphobetaine methacrylate (~295 Da, only phosphate ~95 Da natural) and butyl methacrylate (~142 Da, petrochemical); est. 1:1 ratio → ~95/437 → 0.20 (estimated, no formula/ratio given)
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 synthetic copolymer built from petrochemical methacrylic acid, ethylene-derived amine and butanol, with a phosphate group as the only natural-origin fragment. Comonomer ratio was not supplied, so the value is estimated assuming a typical 1:1 ratio.

In plain English

A conditioning film-former made by joining two lab-made building blocks, one of which carries a mineral phosphate group. Used in hair and skin products to leave a light, smooth coating.

CosIng definition: 2-(N,N,N-Trimethylamino)ethyl 2-(2-methyl-2-propenoyloxy)ethyl phosphate inner salt, polymer with butyl 2-methyl-2-propenoate

Natural alternatives with the same function

Abies Balsamea Resin 100% natural origin

A sticky resin tapped from balsam fir trees, used for its piney scent and to form a thin…

 Acacia Senegal Gum 100% natural origin

The dried gum exuded from the acacia tree, collected by tapping the bark. Used to form a film…

 Albumen 100% natural origin

Egg white. Used in cosmetics to form a film on skin or hair and to help condition them.

 Amorphophallus Konjac Root Extract 100% natural origin

A root extract from the konjac plant that helps form a light film on skin and hair and…

 Astragalus Gummifer Gum 100% natural origin

A natural plant gum, known as tragacanth, harvested from a Middle Eastern shrub. Used as a thickener and…

 Aureobasidium Pullulans Ferment Extract 100% natural origin

An extract of the liquid left after the yeast-like fungus Aureobasidium pullulans is grown on sugars in a…

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. 2POLYQUATERNIUM-51. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  3. 3POLYQUATERNIUM-51. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=POLYQUATERNIUM-51