Database/Film Forming/Polyester-4
Route-dependent · ISO 16128

Is Polyester-4 natural?

It depends. Branched polyester: the adipic acid and pentaerythritol backbone is petrochemical, while the short fatty-acid end caps are coconut-derived, except heptanoic acid, which is made both from castor oil and petrochemically.

INCI namePolyester-4
FunctionFilm Forming · Skin Conditioning
FeedstockAdipic acid and pentaerythritol polycondensed and end-capped with…

Why the score varies

This ingredient is made commercially by more than one route, and ISO 16128 scores the feedstock actually used. Without a supplier certificate of origin the value cannot be claimed.

RouteFeedstockNOIShareNotes
castor-derived heptanoic acidadipic acid + pentaerythritol (petrochemical) capped with coconut C6/C8/C10 acids and castor-derived heptanoic acid0.50All four cap acids natural.
oxo heptanoic acidsame, with heptanoic acid from petrochemical oxo synthesis0.39C7 caps petrochemical.
Ask your supplier. A batch-specific certificate of origin or bio-based carbon test (ASTM D6866) settles which route applies.

How we scored it

Per pentaerythritol unit: C5H8O4 residue 132.1 Da + half of two adipoyl links C6H8O2 112.1 Da (both petrochemical) + two fatty-acyl caps averaging 123.7 Da (equal C6/C7/C8/C10 mix) = 491.6 Da. Caproic, caprylic and capric acids are coconut/palm kernel fractions (natural); heptanoic acid is natural from castor oil or petrochemical from oxo synthesis. Natural share 0.50 (castor C7) or 0.39 (oxo C7). Headline shows the best route.
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

Adipic acid and pentaerythritol polycondensed and end-capped with C6-C10 fatty acids.

In plain English

A film-forming and skin-conditioning ingredient in cosmetics. It combines synthetic petrochemical building blocks with a small amount of natural fatty acids, so overall it is mostly non-renewable.

CosIng definition: Polyester-4 is a copolymer formed by the condensation of Adipic Acid and Pentaerythritol endcapped with Caproic Acid, heptanoic acid, Caprylic Acid and Capric Acid

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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. 2POLYESTER-4. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  3. 3POLYESTER-4. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=POLYESTER-4