PEG-90 Diisostearate
AKA “Polyethylene glycol 90 diisostearate
Synthetic
Ingredient Facts
Peg-90 diisostearate
AKA: Polyethylene glycol 90 diisostearate
Synthetic · Emollient · EWG: 4
Plant-Derived Synthetic
Emollient
Cleanser
Skin Conditioner
Synthetic
Not Clean
Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxo-16-methylheptadecyl)-.omega.-[(1-oxo-16-methylheptadecyl)oxy]- (90 mol EO average molar ratio) Science: Origin: Botanic/Natural | Process: Ethoxylation | Functions: Cleansing Safety Ratings: CIR: Safe as used
Form
Liquid
See origin →
Functions
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Emollient
Fills in the tiny cracks between skin cells to make everything feel smooth and soft. The "silky finish" ingredient.
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Removes Impurities
Traditional Use
A synthetic emulsifier developed in the mid-20th century combining polyethylene glycol with isostearic acid (a branched form of stearic acid). Created to provide stable, mild emulsification for modern cosmetic and personal care formulations.
Skin Types
all-skin-types
Best For
General
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
Yes
EWG
4
CIR
Safe w/Qualifications
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Status
USApermitted
EUrestricted
JAPANrestricted
CANADArestricted
Verified Feb 2026
Data: CosIng · EWG · CIR