Diisostearoyl Trimethylolpropane Siloxy Silicate

Diisostearoyl Trimethylolpropane Siloxy Silicate is a high–molecular weight silicone-resin film former used in color cosmetics (often a few percent) to improve wear and water resistance. As a non-volatile, non-reactive polymer, it has low penetration and is not a known irritant or sensitizer in standard patch-test experience, but the occlusive film it creates can occasionally provoke stinging or flare-ups in highly reactive/eczema-prone skin when layered with other products. For patient safety in severe sensitivities, I rate it very gentle rather than inert. Safety Notes: Diisostearoyl Trimethylolpropane Siloxy Silicate is a silicone resin film former/structuring agent most commonly found in long-wear, water-resistant color cosmetics and some leave-on complexion products; at the low end it appears as a minor film-former around 0.1–1% in foundations, primers, and hybrid skincare-makeup products. In high-wear systems (e.g., transfer-resistant foundations, liquid lip colors, brow gels), it can be pushed into the mid-to-high teens and up to ~25% in specialized consumer OTC products to maximize film integrity and wear, with practical limits driven by viscosity/processing and sensory tack rather than specific regulatory caps.