Database/Emulsifying Surfactant/Polysorbate 61
Mostly petroleum · ISO 16128

Is Polysorbate 61 natural?

Mostly not. Sorbitan (from sorbitol) and stearic acid are natural oleochemical; the polyoxyethylene chain is petrochemical ethylene oxide.

INCI namePolysorbate 61
CAS9005-67-8
FunctionEmulsifying Surfactant · Cleansing Surfactant
FeedstockMade by esterifying sorbitan (dehydrated sorbitol, from plant…

How we scored it

Sorbitan core 146Da + stearate acyl 267Da natural = 413Da; POE chain (~20 mol EO) 20x44=881Da petrochemical -> 413/1294 = 0.32 (assumes standard ~20 mol EO)
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.

How it’s made

Acid-catalysed ring closure of sorbitol (intramolecular SN2). Sorbitan is the ring at the core of every sorbitan ester and polysorbate. Each curved arrow moves one electron pair, and the film ends on the scores for the whole family.

Where it comes from

Made by esterifying sorbitan (dehydrated sorbitol, from plant starch) with stearic acid (vegetable/tallow-derived), then ethoxylating with petrochemical ethylene oxide.

In plain English

An emulsifier combining plant sugar (sorbitol) and stearic acid (a fatty acid from vegetable oil or tallow) with a synthetic ethylene oxide chain, used to blend oil and water.

CosIng definition: Sorbitan, monooctadecanoate, poly(oxy-1,2-ethanediyl) derivs.

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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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. 2POLYSORBATE 61. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  3. 3POLYSORBATE 61. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=POLYSORBATE%2061