Database/Binding/Propylene Glycol Alginate
Mostly natural · ISO 16128

Is Propylene Glycol Alginate natural?

Mostly. The seaweed-derived alginate backbone is natural; the propylene glycol ester groups added for stability are petrochemical, at a typical ~60% substitution.

INCI namePropylene Glycol Alginate
CAS9005-37-2
FunctionBinding · Viscosity Controlling
FeedstockPropylene Glycol Alginate is made by partially esterifying…

How we scored it

Alginate repeat unit ~176 Da (natural, seaweed) esterified at an assumed 60% degree of substitution with propylene glycol (+~35 Da/unit average, petrochemical): 176/211 ~ 0.83.
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

Propylene Glycol Alginate is made by partially esterifying seaweed-derived alginic acid with propylene glycol, a petrochemical from propylene oxide. Degree of esterification varies by grade; ~60% was assumed here.

In plain English

A thickener made by partly reacting seaweed-derived alginate gum with propylene glycol, a small synthetic petroleum-based alcohol, to improve its stability.

Natural alternatives with the same function

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. 2PROPYLENE GLYCOL ALGINATE. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  3. 3PROPYLENE GLYCOL ALGINATE. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=PROPYLENE%20GLYCOL%20ALGINATE