Sodium Laureth Sulfate (SLES)
INCI: Sodium Laureth Sulfate
Also known as: SLES, Sodium lauryl ether sulfate
Last updated:
Sodium Laureth Sulfate (SLES) is an ethoxylated anionic surfactant similar to SLS but milder. It is permitted globally in cosmetics. The primary regulatory concern is 1,4-dioxane — a manufacturing byproduct of ethoxylation that is a known potential human carcinogen. New York State has set a 1,4-dioxane limit of 1 ppm in cosmetics (effective 2023), and California Prop 65 lists 1,4-dioxane as a substance requiring warning above defined exposure levels.
Regulatory status by market
| Market | Status | Detail | Source |
|---|---|---|---|
| European Union | Permitted | — | Not on Annex II or III |
| United Kingdom | Permitted | — | UK Cosmetics Regulation |
| United States | Conditionally permitted | NY State: 1,4-dioxane max 1 ppm. CA Prop 65 warning requirements. | NY State Senate Bill S4389B; CA Prop 65 |
| Canada | Permitted | — | Not on Hotlist |
Safety profile
SLES itself has a clean safety profile and is less irritating than SLS. The risk is the 1,4-dioxane byproduct, which must be reduced to trace levels through vacuum stripping during manufacture. Reputable suppliers provide SLES with 1,4-dioxane below detection limits. Brands should request supplier certificates of analysis showing 1,4-dioxane content.
Common uses
- Shampoos and body washes (milder than SLS)
- Bubble baths and foaming cleansers
- Hand soaps
Primary sources
Regulatory status is current to the "Last updated" date above. Always verify against the regulator's authoritative publication for the specific market and product category before relying on this summary for compliance decisions.
Check your full formulation
Cosmetica analyzes complete ingredient lists across 15 markets with citation-backed findings — not one ingredient at a time.