What it is
Disodium Lauryl Sulfosuccinate is an anionic surfactant from the sulfosuccinate family, valued for being milder than many sulfate-based detergents. It lowers surface tension to help with cleansing, foaming, and dispersing, and it can serve as a secondary surfactant to soften the feel of a system. In a water-based sunscreen it most often appears at low levels as a wetting or emulsifying aid.
Safety & warnings
Sulfosuccinate surfactants are generally considered mild and are often chosen for sensitive-skin formulas. Like all surfactants they can be drying or mildly irritating at high concentrations, but the low levels used in leave-on or rinse-light products are usually well tolerated.
Origin & sourcing
Synthetic; the lauryl portion is typically derived from coconut or palm fatty alcohols.
Questions everyone asks
Is Disodium Lauryl Sulfosuccinate harsh?
It is considered a milder anionic surfactant and is often used where a gentler cleansing or foaming agent is wanted.
Why is a surfactant in a sunscreen?
At low levels it can act as a wetting or emulsifying aid that helps disperse ingredients and stabilize a water-based formula.