Diethylhexyl Succinate

Diethylhexyl succinate is an emollient/solvent ester typically used at low-to-moderate concentrations to improve slip and texture, and esters in this class are generally well-tolerated with low rates of irritation in standard patch testing. Clinically, it is not a known sensitizer like fragrance components, but in severely compromised skin (eczema flares/post-procedure) any solvent-like emollient can occasionally sting or provoke mild irritation, so I rate it very gentle rather than inert. Safety Notes: Diethylhexyl succinate is used as a lightweight emollient/solvent and sensory modifier, so it appears at low levels (~0.1–1%) in complex emulsions (e.g., moisturizers/serums) to fine-tune slip and reduce greasiness. In anhydrous leave-on products (facial oils, makeup/primer bases, silicone-free “dry touch” sunscreens, and oil-based cleansers), it is commonly a primary emollient in the oil phase at ~5–20%, and can reach ~30–40% in minimalist/high-slip consumer formulations where it is used as a major carrier. No specific EU/FDA maximum applies as it is not a restricted cosmetic ingredient, so practical limits are driven by sensory, viscosity, solvency, and overall oil-phase balance rather than regulation.