Silica, a multifaceted mineral ingredient, is widely used in cosmetics for its absorbent, mattifying, and texturizing properties. This raises the question of its proper use. Find out more about this topic in this article.
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Summary
- Silica: an interesting mineral ingredient
- Silica in cosmetics: how is it used?
- And what about the safety and regulatory framework for silica used in cosmetics?
- Sources
Published September 10, 2025,
updated on September 10, 2025,
by
Lilia, Scientific Editor
—
6 min read
Silica: an interesting mineral ingredient.
The silica, or silicon dioxide (SiO₂), is a mineral-based ingredient commonly used in cosmetics. It is extracted from natural raw materials such as quartz, sand, or diatomite. For cosmetic applications, only amorphous forms (precipitated or colloidal), considered safe, unlike crystalline silica, which is banned due to inhalation toxicity.
The amorphous silica is obtained by chemical precipitation from sodium silicates and a strong acid. It is recognized for its absorbent and mattifying. It may help regulate sebum production, reduce shine, and optically smooth pores and fine lines. It is also used as a thickener or mild abrasive in toothpaste. Its versatility and good tolerance make it an appealing ingredient in cosmetic formulations.
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Silica in cosmetics: how is it used?
Silica, particularly in its amorphous (non-crystalline) form, is included in numerous skincare, sun care, hair care, makeup, and exfoliating products. In facial products and sunscreens, it functions as a thickening, stabilizing, and absorbing agent: it improves the texture of the formulations, reduces the greasy feel and reinforces the stability of UV filters, especially in mineral sunscreens. Recent studies on plant-derived silicas (sourced from sugarcane bagasse) have demonstrated good stability and a potential effect on pro-collagen synthesis.
In makeup, silica is valued for its high absorbency: it captures excess sebum and reduces shine, delivering a long-lasting matte finish. Its microporous structure also creates a "soft-focus" effect, optically blurring pores and imperfections for a more even complexion.
In hair care, it is used in dry shampoos and texturizing sprays to absorb sebum at the root without leaving any visible residue, while providing volume and texture. It also serves as an eco-friendly alternative to microplastics, thanks to its biodegradability. Finally, in mechanical exfoliants, silica is employed as particles with controlled size and hardness, enabling a gentle, effective exfoliation that is both respectful of sensitive skin and environmentally sustainable.
And what about the safety and regulatory framework for silica used in cosmetics?
Although silica is used in certain cosmetic formulations, guidelines are provided regarding safety and the use of the silica and the authorized forms. Here are the main recommended conditions of use by the SCCS (Scientific Committee on Consumer Safety) concerning amorphous silica in cosmetics, as set out in Opinion SCCS/1545/15 (2015):
Allowed forms
Amorphous silica (precipitated, hydrated, or colloidal), non-crystalline.Recommended maximum usage concentrations
No strict overall limit is set, but silica is generally used at concentrations ranging up to 15% in cosmetic formulations, depending on the product type.Particle Size and Nanomaterials
Silica can be used in nanoparticle form, but these must be stable, non-toxic and must not penetrate the skin. The SCCS emphasizes that the nanoparticulate form must be evaluated to ensure there is no skin penetration and no systemic toxicity.Inhalation
Amorphous silica is prohibited in products likely to be inhaled, particularly in loose powders, due to the potential respiratory hazard associated with inhaling fine particles.Topical application
Amorphous silica is considered safe for dermal use, including in mucosal products, provided that the particles are not inhaled.
Sources
LENHOFF A. M. Porous silica via colloidal crystallization. Scientific Correspondance (1997).
MARTIN K. R. & al. The chemistry of silica and its potential health benefits. Journal of Nutrition and Aging (2007).
Scientific Committee on Consumer Safety (SCCS). Opinion on Silica, Hydrated Silica, and Silica Surface Modified with Alkyl Silylates (nano form). Public Health (2015).
ANNEREN C. & al. Mesoporous magnesium carbonate for use in powder cosmetics. International Journal of Cosmetics Sciences (2020).
MADUREIRA A. R. & al. Biogenic silica microparticles as a new and sustainable cosmetic ingredient: Assessment of performance and quality parameters. Colloids Surf B. Biointerfaces (2023).
NOLDE J. & al. Investigation on the skin penetration of synthetic amorphous silica (SAS) used in cosmetic products. Toxicology Letters (2024).
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