Alkyl Phosphates

Safety Information

Expert Panel for Cosmetic Ingredient Safety 

The Expert Panel for Cosmetic Ingredient Safety (formerly the Cosmetic Ingredient Review Expert Panel) evaluated available safety information for 28 alkyl phosphate ingredients and concluded they are safe in the present practices of use and concentration in cosmetics when formulated to be non-irritating to skin and eyes:

Potassium Cetyl Phosphate Lauryl Phosphate
Potassium C9-15 Alkyl Phosphate Myristyl Phosphate*
Potassium C11-15 Alkyl Phosphate* Octyldecyl Phosphate*
Potassium C12-13 Alkyl Phosphate Oleyl Ethyl Phosphate*
Potassium C12-14 Alkyl Phosphate* Oleyl Phosphate*
Potassium Lauryl Phosphate Sodium Lauryl Phosphate*
C8-10 Alkyl Ethyl Phosphate* Stearyl Phosphate
C9-15 Alkyl Phosphate Dicetyl Phosphate
C20-22 Alkyl Phosphate Dimyristyl Phosphate*
Castor Oil Phosphate Dioleyl Phosphate
Cetearyl Phosphate* Tricetyl Phosphate*
Cetyl Phosphate Trilauryl Phosphate*
Disodium Lauryl Phosphate* Trioleyl Phosphate
Disodium Oleyl Phosphate* Tristearyl Phosphate*

*Not reported to be in current use. Were these ingredients to be used in the future, the expectation is that they would be used in product categories and at concentrations comparable to others in this group.

Much of the data included in the Expert Panel’s safety assessment were found on the European Chemicals Agency (ECHA) website. The Expert Panel also relied on data demonstrating the safety of several structurally similar ingredients containing chain-length distributions that overlap with alkyl phosphates.

Finally, the Expert Panel was concerned that the potential exists for ocular and/or dermal irritation with the use of products formulated using alkyl phosphates and they specified that products containing them must be formulated to be non-irritating to skin and eyes.

U.S. Food and Drug Administration (FDA)

Potassium lauryl phosphate can be used as an optional finish component in poly(phenyleneterephthalamide) resins, which are indirect food additives intended for repeated contact with food. In this application, the total weight of potassium lauryl phosphate is not to exceed 1% of the base polymer [21CFR177.1632]. Tristearyl phosphate is approved as an indirect food additive as a substance permitted to be used in the formulation of defoaming agents used in the manufacture of paper and paperboard [21CFR176.210].

All of the alkyl phosphates reviewed by the Expert Panel are marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union and used as surfactants, emulsifiers or plasticizers in cosmetics.


Alkyl Phosphates

What Is It?

Alkyl phosphates are the organic esters of ortho-phosphoric acid. These ingredients are mixtures of esters and salts, wherein a phosphate may have one to three alkyl chains and one to two positive ions of potassium or sodium attached. They vary by the identity of the attached alkyl chains, ranging from eight to 22 carbons in length. The alkyl phosphates can be liquids or solids and have solubility in a wide range of solvents.

Why Is It Used?

Most alkyl phosphates are used as surfactants and emulsifiers in cosmetics. However, the phosphates that have three esters attached to them function as plasticizers rather than surfactants. According to 2014 U.S. Food and Drug Administration (FDA) Voluntary Cosmetic Registration Program (VCRP) data, potassium cetyl phosphate, dicetyl phosphate and cetyl phosphate are used most frequently.