Potassium Cetyl Phosphate
Also known as Potassium Cetyl Phosphate, Cetyl Phosphate Potassium Salt, Monopotassium Cetyl Phosphate
“CIR Expert Panel says: safe as used in cosmetics.”
The CIR Expert Panel assessed 28 alkyl phosphates (including Potassium Cetyl Phosphate) and concluded they are safe in present cosmetic practices when formulated to be non-irritating (IJT 38(S2):12-32, 2019). Potassium Cetyl Phosphate is the potassium salt of cetyl alcohol esterified with phosphoric acid — a phosphate ester, not a simple inorganic phosphate salt — used primarily as an anionic oil-in-water emulsifier at concentrations up to ~8.3% (e.g., in mascara). The Panel noted ocular irritation potential at higher concentrations and cautions that products used near the eye should be formulated to be non-irritating.
Highly effective anionic oil-in-water emulsifier — considered a gold-standard emulsifier for difficult-to-stabilize emulsions
Broad formulation utility: creams, sunscreens, cleansers, shampoos, mascaras
Established CIR safety record as part of 28-ingredient alkyl phosphate group assessment
- · Must be formulated to be non-irritating; ocular irritation potential identified at higher concentrations (e.g., up to 8.3% in mascara formulations)
- · Some alkyl phosphates in the group produced irritation in non-human abraded-skin studies when applied undiluted
CIR Quick Reference Table (September 2022) — POTASSIUM CETYL PHOSPHATE row: Finding=SQ, Citation=IJT 38(S2):12-32,2019
“Potassium Cetyl Phosphate | SQ | The CIR Expert Panel concluded the following 28 alkyl phosphates are safe in the present practices of use and concentration in cosmetics when formulated to be non-irritating...Potassium Cetyl Phosphate... | IJT 38(S2):12-32,2019”— QuickReferenceTable_AllConclusionTypes.pdf, p. 447