Emulsifying Wax
Emulsifying wax can be a generic term that refers to a waxy ingredient used to emulsify water and oil in cosmetics or other products. There are several different formulas for emulsifying wax, but most consist of a petroleum or plant-based wax material that is treated with a surfactant.
All emulsifying waxes, regardless of their components, are considered synthetic ingredients.
Cosmetic Ingredient Declaration
In most cases, an emulsifying wax is treated as a blended ingredient, and the components are listed individually in a cosmetic ingredient declaration.
There is, however, one exception.
The regulations covering the ingredient declaration state that the ingredients should be named according to the list of resources contained in the regs.1 The National Formulary, which is the third approved source, contains a formulation for an emulsifying wax. When an emulsifying wax meets the NF standard, it can be listed as “Emulsifying Wax NF” in the ingredient declaration.
Emulsifying Wax N.F.
The definition and formulation of emulsifying wax from the National Formulary monograph is:2
“A waxy solid prepared from cetostearyl alcohol containing a polyoxyethylene derivative of a fatty acid ester of sorbitan.”
Cetostearyl alcohol is also called cetearyl alcohol or cetylsteryl alcohol. The currently accepted common name, as listed in the International Cosmetic and Ingredient Dictionary, is “cetearyl alcohol.”
A polyoxyethylene derivative of a fatty acid ester of sorbitan is a polysorbate. Polysorbates are identified with a number (e.g., Polysorbate 20 or Polysorbate 80).
In order to meet the National Formulary definition of Emulsifying Wax NF, it must be a blend of cetearyl alcohol and a polysorbate.
Any of the various polysorbates could be used and still meet the monograph requirements, and manufacturers can choose which polysorbate to use. As a result, you get different results when using an Emulsifying Wax NF from a different supplier – even though the ingredient name is the same
If your Emulsifying Wax meets the NF monograph, you can list it in the ingredient declaration as Emulsifying Wax NF. If it uses different ingredients and doesn’t meet the NF monograph, you must treat it as a blended ingredient and list the component ingredients in descending order in the whole.
Safety
The Cosmetic Ingredient Review Expert Panel reviewed the safety and use of Emulsifying Wax NF in 1984.3 Over 35 animal and human studies were cited in the review and none showed more than minor irritation or reaction. They found that Emulsifying Wax NF was safe to use as a cosmetic ingredient at the then-present practices and concentrations of use (up to about 10%).
The CIR Expert Panel revisited Emulsifying Wax NF in 2003. They reviewed additional studies and based on the data available at that time, the CIR determined not to open a new safety assessment.4
1 21 CFR 701.3(c)(2)(ii) Designation of ingredients.
2 US Pharmocopeia. “Emulsifying Wax.” http://www.pharmacopeia.cn/v29240/usp29nf24s0_m88980.html
3 Cosmetic Ingredient Review (November 3, 1984). "Final Report on the Safety Assessment of Fossil and Synthetic Waxes." Journal of the American College of Toxicology.
4 "Annual Review of Cosmetic Ingredient Safety Assessments—2002/2003". International Journal of Toxicology. 2005 (24(1_suppl): 1–102. doi:10.1080/10915810590918625.
