Diisooctyl Succinate

Diisooctyl succinate is a non-volatile emollient/skin-conditioning ester used to improve slip and reduce tack, typically at a few percent up to ~10% in leave-on products. Esters of this type are generally non-sensitizing and show low reactivity in patch testing, but any lipid emollient can rarely sting or provoke subjective irritation on severely compromised or eczematous skin, especially under occlusion or alongside other irritants. Given its low inherent irritancy yet real-world reports of occasional intolerance in highly reactive patients, it fits best as very gentle rather than truly inert. Safety Notes: Diisooctyl succinate is an emollient/skin-conditioning ester typically used at low levels (~0.1–1%) as a secondary emollient/slip agent in lotions, sunscreens, and color cosmetics, with trace-to-low use also seen in rinse-off cleansers. In anhydrous and high-oil-phase leave-on products (lip oils/balms, facial oils/serums, makeup bases), it can be a primary emollient and reach ~10–40% depending on the desired sensory profile and solvency; higher levels are uncommon in rinse-off formats due to cost and limited need. No specific EU/FDA concentration limit is generally set for this ester in cosmetics, so the upper end is driven mainly by aesthetics, stability, and compatibility with the oil phase.