Database/Emulsifying Surfactant/PEG-9 Stearate
Mostly petroleum · ISO 16128

Is PEG-9 Stearate natural?

Mostly not. Stearic acid (oleochemical) esterified with 9 ethylene-oxide units (petrochemical); only the fatty-acid portion counts natural.

INCI namePEG-9 Stearate
CAS9004-99-3
FunctionEmulsifying Surfactant
FeedstockMade by reacting oleochemical stearic acid with about…

How we scored it

Stearoyl (natural, C18H35O, 267 Da) + PEG-9 chain (petrochemical, ~414 Da); description's 9 mol EO used, not the mismatched C20H40O3/328.5 formula. 267/681 = 0.39.
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

Made by reacting oleochemical stearic acid with about 9 units of petrochemical ethylene oxide. The supplied formula/MW (one-EO structure) contradicts the '9 mol EO' description, so the description is treated as authoritative.

In plain English

An emulsifier that helps blend oil and water in creams and lotions. It is made from a natural fatty acid combined with a petroleum-derived ethylene oxide chain.

CosIng definition: Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxooctadecyl)-.omega.-hydroxy- (9 mol EO average molar ratio)

Natural alternatives with the same function

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 Behenic Acid 100% natural origin

A long-chain fatty acid from vegetable oil, used to thicken and stabilise creams and conditioners. It is extracted…

 C10-16 Alkyl Glucoside 100% natural origin

A mild, sugar-based cleansing and emulsifying surfactant made by combining plant-derived fatty alcohols (coconut/palm) with glucose from starch.…

 C12-20 Alkyl Glucoside 100% natural origin

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 C18-36 Acid 100% natural origin

A blend of long-chain plant fatty acids used as a mild cleanser and thickener, giving body and 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. 2PEG-9 STEARATE. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  3. 3PEG-9 STEARATE. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=PEG-9%20STEARATE