Polyglyceryl-4 Caprate

Polyglyceryl-4 caprate is a nonionic surfactant/solubilizer (capric acid ester) typically used at low concentrations (~0.5–5%) to help disperse oils and improve cleansing or preservative efficacy. While generally well-tolerated compared with harsher anionic surfactants, caprate-based solubilizers can still disrupt the stratum corneum and sting on compromised skin, with irritation risk increasing in leave-on products or when combined with other surfactants/actives. Given sensitive-skin and eczema populations, I rate it as gentle but not inert, warranting a low yet non-negligible irritancy score. Safety Notes: In commercial leave-on emulsions and micellar/toner-type products, Polyglyceryl-4 Caprate is often used at very low levels (~0.05–0.5%) as a co-emulsifier/solubilizer and mild antimicrobial/skin-feel modifier. Rinse-off cleansers and makeup removers commonly sit around ~0.5–3% for solubilization and foam/cleansing support. The highest consumer-available levels observed are in anhydrous cleansing oils/balms and high-solubilizer systems (including some “preservative-free”/self-preserving style formulas) where it can reach ~5–10%, with practical upper limits driven by clarity/phase behavior, odor/feel, and potential for increased irritation at very high surfactant loads.