Database/Emulsifying Surfactant/PEG-20 Stearate
Mostly petroleum · ISO 16128

Is PEG-20 Stearate natural?

Mostly not. The stearic acid ester portion is natural and oleochemical, but the ethylene oxide chain still contributes most of the mass.

INCI namePEG-20 Stearate
CAS9004-99-3
FormulaC20H40O3 · 328.5 Da
FunctionEmulsifying Surfactant · Humectant
FeedstockStearic acid, from vegetable oil or tallow, is…

How we scored it

Stearoyl group (natural, 267 Da) + PEG-20 chain (petrochemical, 20×44+18=899 Da) - H2O = 1165 Da total; 267/1165 ≈ 0.23.
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

Stearic acid, from vegetable oil or tallow, is esterified onto a polyethylene glycol chain made from petrochemical ethylene oxide. The PEG portion outweighs the natural fatty acid portion in this molecule.

In plain English

An emulsifying and moisturizing ingredient made by attaching a fatty acid, from plant oil or tallow, to a shorter chain of synthetic ethylene oxide units. Less than a quarter of its weight comes from the natural fatty acid part.

CosIng definition: Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxooctadecyl)-.omega.-hydroxy- (20 mol EO average molar ratio)

Natural alternatives with the same function

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 C10-16 Alkyl Glucoside 100% natural origin

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 C12-20 Alkyl Glucoside 100% natural origin

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 C18-36 Acid 100% natural origin

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Structure

2D structure of PEG-20 Stearate

2-hydroxyethyl octadecanoate

PubChem CID 24762 ↗

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. 2PEG-20 Stearate. PubChem CID 24762. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3PEG-20 STEARATE. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4PEG-20 STEARATE. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=PEG-20%20STEARATE