C15-19 Alkane

C15-19 Alkane is a lightweight emollient/hydrocarbon solvent (often used as an isododecane alternative) typically included at several percent up to higher levels to improve slip and reduce greasiness. In clinical use it is generally non-sensitizing and has very low irritancy potential because it is nonpolar, nonreactive, and does not alter skin pH; reactions are uncommon and usually relate to overall formula effects (occlusion, friction) rather than the ingredient itself. Given its excellent tolerance even in compromised barriers but acknowledging rare individual reactivity, it fits an exceptionally gentle score rather than completely inert. Safety Notes: C15-19 Alkane (a light emollient/hydrocarbon often used as a volatile-like silicone alternative) appears at low levels (~0.1–1%) in emulsions and cleansers primarily for slip, spreadability, and sensory optimization. In leave-on oils, oil-serums, silicone-free primers, and anhydrous balm-to-oil textures it can serve as a principal carrier/emollient, commonly 10–40% and reaching ~60–70% in high-slip, fast-dry consumer-available anhydrous formulas. It is generally not subject to a specific EU/FDA concentration cap for cosmetics, so the upper end is driven mainly by product format, stability, and sensorial targets rather than regulation.