• What Is Sodium Laureth Ether Sulfate? Sodium Laureth Ether Sulfate (SLES) is a widely used anionic surfactant known for its powerful foaming, emulsifying, and cleansing capabilities. Chemically represented as CH₃(CH₂)₁₀CH₂(OCH₂CH₂)ₙOSO₃Na, SLES is