At a glance
- CAS number
- 151-21-3
- INCI name
- Sodium Lauryl Sulfate
- Function
- surfactant, emulsifier, cleansing, foaming agent, emulsifying
- Typical use level
- 0.5%–15%
- Solubility
- water
- Stable pH
- 6–8
CAS number and synonyms are sourced from PubChem. Function, usage levels, pH and compatibility are AI-assisted formulation guidance — verify against your supplier's technical data sheet and applicable regulations before use.
Also known as
Sodium dodecyl sulfate Sodium dodecylsulfate Sodium lauryl sulphate Sodium dodecyl sulphate Sodium n-dodecyl sulfate Dodecyl sodium sulfate Anticerumen Duponal Gardinol Stepanol methyl Neutrazyme Stepanol wac
Compatibility
Works well with:
Sodium Chloride Cocamidopropyl Betaine Cocamide DEA Cocamide MEA Glycerin Sodium Laureth Sulfate Citric Acid Sodium Benzoate PEG-7 Glyceryl Cocoate
Use caution with:
Cationic Surfactants Quaternium-15 Behentrimonium Chloride Cetrimonium Chloride High-Cation Polymers Polyquaternium-10 Cationic Guar L-Ascorbic Acid Proteins
SLS is an anionic surfactant and will form insoluble complexes or lose efficacy when combined with cationic surfactants or cationic conditioning polymers due to charge-charge interactions. Highly acidic environments below pH 6 can cause hydrolysis and reduced performance, while very alkaline conditions above pH 8 may increase skin irritation potential. It can also denature or precipitate proteins, limiting compatibility with protein-based actives.
Formulation notes
Known primary irritant at higher concentrations; EU and industry guidelines generally recommend keeping levels below 1% in leave-on products and using with caution in rinse-off formulas targeting sensitive skin. Often replaced or blended with milder surfactants (e.g., SLES, betaines) to reduce irritancy. Not recommended in leave-on formulations due to transepidermal water loss concerns and mucosal irritation risk.
Related ingredients
- Lauryl GlucosideSurfactant
- Sodium Cocoyl GlutamateSurfactant
- Sodium Cocoyl IsethionateSurfactant
- Behenyl PEG/PPG-20/20 DimethiconeEmulsifier
- Cetearyl GlucosideEmulsifier
- Cetyl PhosphateEmulsifier