Sodium Palmitate

Sodium palmitate is the sodium salt of palmitic acid and a primary soap surfactant used at high levels in bar soaps; at its functional alkaline pH it can strip lipids and disrupt the stratum corneum, which is a common trigger for stinging, dryness, and eczema flares. While not a classic strong sensitizer, its irritancy in compromised or very sensitive skin is clinically relevant due to surfactant/pH effects and frequent, cumulative exposure (hand/body washing). For patient safety—especially in eczema-prone populations—this warrants a moderate irritancy score with patch testing/avoidance in flaring skin. Safety Notes: Sodium palmitate is most commonly encountered as a soap surfactant/structurant in rinse-off bar cleansers, where it can appear at very low levels (~0.1–2%) as a minor fatty-acid soap in syndet/hybrid cleansing bars or in formulas using small amounts of fatty-acid neutralization for structuring. At the high end, traditional soap bars and soap-based cleansing bars marketed to consumers can contain sodium palmitate as a primary component, with finished-product levels commonly in the ~40–80% range and specialty high-soap bars reaching roughly ~85% depending on water/glycerin/other soap salts content; it is uncommon in leave-on products except at trace/low levels due to alkalinity/irritation constraints.