Si
Silica
Silica · Silica Dimethyl Silylate
Mineral powder. Optical-blurring effect in primers and finishing powders.
What it does
Silica in cosmetics functions as an oil-absorber, a viscosity modifier, and a soft-focus optical blurring agent. The 'soft focus' effect is what makes it a primer staple — it scatters light to visually smooth the skin's surface. Generally inert; rare for it to be the cause of a reaction. Hydrated silica is a slightly different INCI used in toothpaste as a mild abrasive.
The evidence, graded
expert consensusSilica and hydrated silica work as scrubbing agents, absorbers, anticaking agents, bulking agents and opacifiers. An expert panel judged the synthetic amorphous forms safe when formulated not to irritate. How the silica is made was treated as decisive.Burnett 2025 · International journal of toxicology ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Pairs worth knowing
Browse all 668 ingredients — grouped by what they do, each with whatever evidence we can cite.
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