Sodium Laureth Sulfate

Sodium Laureth Sulfate is an anionic surfactant used primarily for cleansing/foaming, commonly at a few percent to ~10%+ in rinse-off products, and it has well-documented irritant potential through barrier lipid disruption and increased transepidermal water loss. Human patch testing and real-world use show higher rates of stinging, dryness, and eczema flares in sensitive individuals compared with milder surfactants, with risk amplified by frequent use and concurrent actives. Given its consistent association with irritant contact dermatitis—especially in compromised skin—this warrants a significant irritancy score for patient safety. Safety Notes: In consumer products, Sodium Laureth Sulfate is most commonly used in rinse-off formats (cleansers, shampoos, body washes, bubble baths), with very low levels (~0.2–1%) appearing in mild cleansing emulsions, micellar-type rinse-off cleansers, and as a secondary anionic surfactant/foam booster alongside amphoterics. The high end (15–25%) is observed in high-foaming shampoos, liquid hand soaps, and bath products where SLES is a primary surfactant; higher levels are generally limited by irritation potential and viscosity/salt-curve constraints, and SLES is rarely used in true leave-on products except at trace levels from carryover.

Suitability