SLES (SODIUM LAURETH SULFATE)
Commonly Found In
Overview
SODIUM LAURETH SULFATE (SLES) is an anionic surfactant derived from coconut or palm kernel oil through ethoxylation and sulfation. It is widely used as a primary cleansing agent in shampoos, body washes, and facial cleansers due to its excellent foaming and detergency properties. SLES is considered milder than SLS because the ethoxylation process reduces protein denaturation and skin irritation potential.
Also known as: SLES, Sodium Lauryl Ether Sulfate, Sodium Laureth-2 Sulfate, Texapon N70
Key Benefits
SLES is a cleansing surfactant, not a skin-active ingredient in the therapeutic sense. Studies suggest that at typical rinse-off concentrations, it effectively removes sebum, dirt, and cosmetics from the skin surface. However, clinical evidence also indicates that frequent use at high concentrations may disrupt the skin barrier and increase transepidermal water loss, particularly in individuals with sensitive or compromised skin.
Supporting Research
- β’ CIR Expert Panel (2010) β safety assessment of sodium laureth sulfate in rinse-off products
- β’ LΓΆffler et al. (2003) β cumulative irritation study comparing SLS and SLES in atopic skin (Dermatology)
Skin Compatibility Ratings
Comedogenic Rating
Minimal comedogenic risk in rinse-off products; concern is greater for leave-on applications where residual surfactant remains on skin
Source: Kligman & Mills comedogenicity scale
Irritancy Rating
Irritancy score of 2 reflects concentration-dependent potential; at typical shampoo/cleanser concentrations (5β15%) in rinse-off products, irritation is generally low. Higher concentrations or leave-on use increases risk. Less irritating than SLS due to ethoxylation.
Source: CIR Expert Panel; clinical irritation studies
Typical Use Concentration
Range
3β20%
Optimal
5β12% in rinse-off cleansers
EU and US permit use in rinse-off products; CIR confirms safety in rinse-off at typical concentrations. Leave-on use should be avoided or limited to very low concentrations. 1,4-dioxane controls are required.
Works Well With / Avoid
Works Well With
Use With Caution
Commonly paired with cocamidopropyl betaine (3:1 ratio) to reduce irritation and improve foam quality. 1,4-dioxane byproduct from ethoxylation must be controlled to <10 ppm (EU) or <20 ppm (US) through vacuum stripping. Performs best at pH 6β8.
Commonly Found In
Global Regulation Summary
Overview of current status across major international markets.
Detailed Regional Status
| Region | Status | Max Conc. | Conditions | Source |
|---|---|---|---|---|
| πͺπΊ EU | Allowed | - | Must meet 1,4-dioxane limits | Official β |
| πΊπΈ USA | Allowed | - | FDA recommends <20 ppm 1,4-dioxane | Official β |
| π―π΅ Japan | Allowed | - | - | Official β |
| π°π· Korea | Allowed | - | - | Official β |
| π¬π§ UK | Allowed | - | Follows EU standards | Official β |
π Why Regulations Differ
SLES is permitted across all major markets in rinse-off cosmetic formulations. The primary regulatory constraint is the byproduct 1,4-dioxane, which must be controlled through manufacturing (EU: <10 ppm; US FDA: <20 ppm recommended). The 'sulfate-free' marketing trend is consumer-driven rather than regulatory. No major cross-market divergence on SLES itself.
Regulation Analysis
Category Comparison
98% of SURFACTANT - CLEANSING ingredients (186 of 190) are banned in the EU, but this one is approved.
πΏ Natural Sources
SLES is derived from lauryl alcohol, which is obtained from coconut oil (Cocos nucifera) or palm kernel oil (Elaeis guineensis). The starting fatty acids (primarily C12-C14 chain length) are found naturally in these tropical plant oils, which contain 45-50% lauric acid. While the raw materials are plant-based, SLES itself does not exist in nature and requires chemical modification.
π How It's Made
SLES is manufactured through a two-step process: (1) Ethoxylation: Lauryl alcohol (from coconut/palm oil) reacts with ethylene oxide (EO) under pressure at 120-180Β°C with alkaline catalyst. Typically 1-4 moles of EO are added (average 3 moles for cosmetic grade), creating laureth-3. This step reduces the irritation potential compared to SLS. (2) Sulfation: The ethoxylated alcohol is then reacted with sulfur trioxide (SO3) or chlorosulfonic acid, followed by neutralization with sodium hydroxide to form the sodium salt. The ethoxylation step is critical - it inserts ethylene oxide units between the fatty chain and sulfate head group, providing a 'cushion' that reduces protein binding. However, 1,4-dioxane can form as a byproduct during ethoxylation and must be removed through vacuum stripping to meet safety standards (<10 ppm in finished products).
π Uses in Cosmetics
SLES is used in shampoos (5-15%), body washes (5-12%), facial cleansers (3-8%), bubble baths (10-20%), and liquid hand soaps (8-15%). It functions as a primary surfactant providing cleansing and foam generation. SLES has a critical micelle concentration (CMC) of approximately 8.2 mM and creates abundant, stable foam even in hard water. It is often combined with amphoteric surfactants like cocamidopropyl betaine (typical ratio 3:1 SLES:betaine) to further reduce irritation and improve foam quality. The ethoxylation level affects performance: 1-2 EO moles provide higher foam but more irritation, while 3-4 EO moles offer better mildness but slightly reduced foam. Most commercial formulations use SLES with 2-3 moles EO. It is less effective in acidic pH (<5.5) and performs best at pH 6-8.
π¬ Other Applications
SLES is widely used in household cleaning products including laundry detergents, dishwashing liquids, and all-purpose cleaners (typically 5-20% concentration). In industrial applications, it serves as an emulsifier in textile processing, leather treatment, and agricultural formulations. The pharmaceutical industry uses SLES in topical drug delivery systems and medicated shampoos for conditions like seborrheic dermatitis. It is also employed in firefighting foams, ore flotation processes in mining, and as an emulsion polymerization aid in latex production. The global SLES market was approximately 550,000 metric tons in 2020, with household and personal care products accounting for about 75% of consumption.
π‘ Fun Facts
- β’ SLES was developed in the 1940s as a milder alternative to SLS after complaints of scalp irritation from early synthetic shampoos. The chemical modification modification reduced protein denaturation by approximately 40%.
- β’ The 'sulfate-free' marketing trend beginning around 2010 has driven many brands to reformulate with alternative surfactants, despite SLES being considered safe at typical use concentrations by regulatory agencies worldwide. This trend was partly fueled by concerns about color-treated hair fading, though studies show surfactant type is less important than total surfactant concentration and pH.
- β’ The number in 'laureth' indicates chemical modification level: laureth-1 has 1 mole EO, laureth-3 has 3 moles. Higher numbers mean milder but less foaming. Commercial SLES is usually laureth-2 to laureth-3.
Related Skin Concerns
Data Sources
- β’ CIR Expert Panel Final Report on sodium laureth sulfate (2010)
- β’ EU CosIng database
- β’ FDA cosmetic ingredient database
- β’ LΓΆffler et al., Dermatology 2003;206(2):119-23
Last data verification: 2026-04-12
Related Ingredients
COCAMIDE DEA
CAPB
COCAMIDOPROPYL BETAINE
Tween 20
POLYSORBATE 20
Tween 80
POLYSORBATE 80
LANOLINAMIDE DEA
TRIETHANOLAMINE
Learn More
Frequently Asked Questions
What is SODIUM LAURETH SULFATE used for in cosmetics?
SODIUM LAURETH SULFATE is primarily used for surfactant - cleansing in cosmetic products. It also serves as surfactant - emulsifying, surfactant - foam boosting. The ingredient is commonly found in cleansers, shampoos, and body washes.
Which countries regulate SODIUM LAURETH SULFATE?
SODIUM LAURETH SULFATE is approved for cosmetic use in all major markets: EU, JP, US, UK, KR, with no significant restrictions.
Where can I find official regulation information about SODIUM LAURETH SULFATE?
Official information about SODIUM LAURETH SULFATE regulations can be found on government websites: EU CosIng database, US FDA Cosmetics page, Japan MHLW cosmetics standards, UK Government cosmetics guidance, and Korea MFDS. Always verify regulatory status with these official sources before making formulation decisions.
Disclaimer
The information on this website is for educational and informational purposes only and is not intended as medical advice. While we strive for accuracy based on official government databases, cosmetic regulations change frequently. Always consult with a qualified professional or refer to the latest official regulatory documents for compliance. We are not responsible for any actions taken based on the information provided here.