Alcohol. Dipropylene Glycol

Well-established humectant with a strong safety record at standard cosmetic use levels (<10%). Irritation risk rises at higher concentrations on compromised skin. Formulate below 10% for sensitive skin applications or substitute with butylene glycol for a lighter, lower-irritation profile. Hygroscopic mechanism pulls water into stratum corneum rather than forming an occlusive barrier. Penetration-enhancing properties require co-ingredient safety consideration.

CIR reviewed; considered safe. FDA GRAS for food use. Higher irritation profile at concentrations above 10-15%, particularly on compromised skin. Neither comedogenic nor occlusive at standard use levels.