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Quaternium-18 Bentonite

What Quaternium-18 Bentonite is & what it does

Quaternium-18 Bentonite is a clay mineral, bentonite, that has been modified with a quaternary ammonium compound to make it work in oil-based systems. In sunscreen and skincare formulas it acts mainly as a viscosity controller and suspending agent, helping to thicken oils and keep pigments and other particles evenly dispersed. This makes it useful for stabilizing the texture of emulsions and anhydrous products.

What does Quaternium-18 Bentonite do in skincare?

Quaternium-18 Bentonite is a modified clay used as a viscosity controller and suspending agent. In sunscreen and skincare formulas it helps thicken oils and keeps pigments and particles evenly dispersed. This supports a stable, uniform texture.

Is Quaternium-18 Bentonite natural or synthetic?

Quaternium-18 Bentonite starts from a natural clay mineral, bentonite, that is then modified with a quaternary ammonium compound. This makes it a hybrid ingredient: a naturally sourced clay that has been chemically treated. The modification allows it to work in oil-based systems.

Is Quaternium-18 Bentonite safe?

Quaternium-18 Bentonite is a widely used clay-based thickener and suspending agent in cosmetics. As a large-particle mineral derivative it is generally used at functional levels in finished products. If you have specific concerns, reviewing the ingredient list and consulting a professional is advisable.

Sunscreens with Quaternium-18 Bentonite

We rate 25 sunscreens that contain it, showing the top 10 by overall score:

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