What is it?
A water-soluble thickener made from cellulose, the fiber that gives plants their structure. The cellulose is reacted with ethylene oxide in the presence of sodium hydroxide, which attaches hydroxyethyl groups that let it dissolve in water. It thickens gels, shampoos, conditioners, lotions and hair dyes, stabilizes emulsions and forms a light film. It is also used in household cleaners and in eye-drop solutions such as artificial tears.
Key information
- Hydroxyethylcellulose is made by reacting cellulose with ethylene oxide, a process chemists call ethoxylation.
- Its name does not contain PEG, -eth- or polyoxyethylene, the label cues usually used to spot ethoxylated ingredients.
- The CIR Expert Panel concluded in its 2009 amended assessment of cellulose and related polymers that it is safe as used in cosmetics.
- We found no published measurements of ethylene oxide or 1,4-dioxane residues in cosmetic-grade hydroxyethylcellulose.
More information
Hydroxyethylcellulose starts as purified cellulose, which is reacted with ethylene oxide in the presence of sodium hydroxide. PubChem's reference entry describes this step as an ethoxylation. The added hydroxyethyl groups make the cellulose dissolve in water, where its long chains build thickness.
The Cosmetic Ingredient Review (CIR) Expert Panel first reviewed hydroxyethylcellulose in 1986. In its 2009 amended safety assessment of cellulose and related polymers, the Panel concluded that it is safe as used in cosmetics.
Our Red Light ratings for ethoxylates and PEGs rest largely on the traces of ethylene oxide and 1,4-dioxane that ethoxylation can leave behind. The FDA's guidance on 1,4-dioxane points to ingredients named with PEG, polyethylene, polyoxyethylene, -eth- or -oxynol-; it does not mention cellulose derivatives. For a closely related food-grade cellulose made with ethylene oxide, ethyl hydroxyethyl cellulose, EU food scientists in 2002 listed ethylene oxide, 1,4-dioxane and 2-chloroethanol as possible impurities. They accepted it only with limits of 0.5 mg/kg for 1,4-dioxane and 2-chloroethanol and with ethylene oxide below the limit of detection. We did not find published measurements of these residues in cosmetic-grade hydroxyethylcellulose.
Reality check: the finished polymer has a clean CIR safety conclusion, but it is an ethoxylated ingredient even though its name doesn’t say so. If you avoid ethoxylated ingredients as a rule, add hydroxyethylcellulose and other “hydroxyethyl” celluloses to your list.
Sources: Cosmetic Ingredient Review: Quick reference table of safety conclusions (2016); PubChem: Hydroxyethyl cellulose; FDA: 1,4-Dioxane in cosmetics, a manufacturing byproduct; European Commission Scientific Committee on Food: Opinion on 1,4-dioxane, 2-chloroethanol and glycol impurities in food additives and ethyl hydroxyethyl cellulose (2002)
