What is it?
A gentle cleansing agent (surfactant) made by joining glucose, which can come from corn, potato or wheat starch, with decyl alcohol, a fatty alcohol that can come from coconut or palm oil. It foams and helps water lift away oil and dirt, so it is common in shampoos, body washes, facial cleansers and baby washes. It also turns up in some sunscreens, lotions and household cleaners.
Key information
- The CIR Expert Panel concluded that decyl glucoside and 18 related alkyl glucosides are safe as used when products are formulated to be non-irritating.
- It is not a sulfate and is not ethoxylated, so it is not a source of 1,4-dioxane.
- It can cause allergic skin reactions in a small share of people, and the American Contact Dermatitis Society named alkyl glucosides its 2017 Allergen of the Year.
More information
Decyl glucoside belongs to a family called alkyl glucosides. They are made by reacting glucose with a fatty alcohol under acidic conditions, a process the Cosmetic Ingredient Review (CIR) describes as “green” because both starting materials can come from renewable plant sources. The result is a nonionic surfactant: unlike sodium lauryl sulfate or sodium laureth sulfate, it contains no sulfate, and it is not made with ethylene oxide. The FDA says 1,4-dioxane can be present in ingredients whose names include “PEG,” “-eth-” or “-oxynol-”; decyl glucoside is not one of them.
In its 2011 review, the CIR Expert Panel found decyl glucoside at most slightly irritating in human patch tests, and it caused no irritation or allergic reactions in repeated-insult patch tests at up to 5 percent. It was the most widely used alkyl glucoside, reported in 492 products, mostly rinse-off, at up to 33 percent in rinse-off formulas. Because cleansers can irritate at higher strengths, the Panel concluded the alkyl glucosides are safe as used when products are formulated to be non-irritating.
The main caution is allergy. Dermatologists have reported a growing number of allergic reactions, and the American Contact Dermatitis Society named alkyl glucosides its 2017 Allergen of the Year. Among patients patch tested for suspected skin allergies, reactions to decyl glucoside rose from 1.5 percent in 2009 to 2012 to 1.7 percent in 2013 to 2014. Reactions have been linked to rinse-off products and to leave-on products such as sunscreens. People allergic to one glucoside may also react to others, so check labels for lauryl glucoside, coco-glucoside and cetearyl glucoside as well.
Sources: Cosmetic Ingredient Review: Final safety assessment of decyl glucoside and other alkyl glucosides (2011); The Dermatologist: Update on alkyl glucosides (2017); Contemporary Clinic: Contact dermatitis and the Allergen of the Year, 2017; FDA: 1,4-Dioxane in cosmetics, a manufacturing byproduct
