Sodium Tallowate

Sodium tallowate is a soap (alkaline fatty acid salt) typically used at high concentrations in bar cleansers, where its naturally high pH and surfactant action can disrupt the stratum corneum and increase transepidermal water loss. Clinically, true allergy is uncommon, but irritant contact dermatitis and eczema flares are well-documented in sensitive skin due to barrier disruption, especially with frequent use or compromised skin. Given its routine use level and predictable irritancy in atopic/reactive populations, it warrants a notable irritancy score. Safety Notes: Sodium tallowate is a primary soap base in traditional bar soaps and some shave soaps; in such products it commonly appears at very high levels (often the dominant fatty-acid sodium salt fraction), with consumer-available bars reaching roughly 60–85% of the finished product (balance being water, glycerin, other fatty acid salts, fragrance, chelants, etc.). At the low end, it is occasionally used in blended surfactant systems (e.g., certain liquid/cream cleansers or syndet-style hybrids, or as a minor structurant/foam modifier) where it can appear around ~0.1–1%. This is essentially a rinse-off ingredient in mainstream use; meaningful leave-on use is uncommon due to alkalinity/irritation and soap instability in leave-on emulsions.

Suitability