Noun
ethoxylation (plural ethoxylations)
(organic chemistry) Treatment or reaction with ethylene oxide
1,4-Dioxane contamination Some products containing SLES have been found to also contain traces (up to 279 ppm) of 1,4-dioxane ; this is formed as a by-product during the ethoxylation step of its synthesis. Source: Internet
The related surfactant sodium lauryl sulfate (also known as sodium dodecyl sulfate or SDS) is produced similarly, but without the ethoxylation step. Source: Internet