Stearyl Phosphate

AKA: Octadecyl dihydrogen phosphate, Monostearyl phosphate, 2958-09-0, Monooctadecyl orthophosphate, Stearyl acid phosphate
Plant-Derived
Cleanser
Emulsifier
Clean
Phosphoric acid, monooctadecyl ester
Formula
C18H39O4P
Mol. Weight
350.50
CAS #
2958-09-0
Form
Powder
Functions
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Emulsifying
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Cleansing Surfactant
Emulsifier
Removes Impurities
Mixes Oil & Water
Traditional Use
A synthetic compound developed for use in cosmetics as an emulsifier and conditioning agent. No traditional historical use; created to meet modern formulation needs in the 20th century.
EWG
1
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Status
USApermitted
EUrestricted
JAPANrestricted
CANADArestricted
Skin Types
all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewed1 paper
⚖️Regulatory1 listing
🛡️Safety-assessed2 reviews
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR