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Phenylbenzimidazole Sulfonic Acid

What Phenylbenzimidazole Sulfonic Acid is & what it does

A water-soluble UVB filter (ensulizole) that dissolves in the water phase, so it enables light, fast-absorbing, non-greasy textures. It contributes UVB protection with little of the heavy feel of oil-based filters.

What is Phenylbenzimidazole Sulfonic Acid and what does it do in sunscreen?

Phenylbenzimidazole Sulfonic Acid, also known as ensulizole, is a UVB filter. Unlike most filters it is water-soluble, so it dissolves in the water phase of a formula instead of the oils. That lets it add UVB protection while keeping textures light, fast-absorbing, and non-greasy.

Is Phenylbenzimidazole Sulfonic Acid a UV filter?

Yes. It is a UVB filter, meaning it mainly protects against the shorter UVB wavelengths that drive sunburn. It does little against UVA on its own, so formulators usually pair it with UVA filters to reach broad-spectrum coverage. Its water solubility is what makes it useful in light, watery sunscreens.

Is Phenylbenzimidazole Sulfonic Acid safe?

Yes, as a permitted sunscreen filter used within approved limits. Like all UV filters it is regulated, and it is included in formulas at controlled concentrations. It is not flagged as an allergen in our data, and at label levels it is well tolerated by most people.

Does Phenylbenzimidazole Sulfonic Acid clog pores?

Generally no. Because it is water-soluble rather than an oil-based filter, it does not add the greasy, occlusive feel that some heavier filters do, and it is not flagged as comedogenic. It is an unlikely pore-clogging culprit and is favored in lightweight, fast-absorbing textures.

What else is Phenylbenzimidazole Sulfonic Acid called?

Its common name is ensulizole, and that is the same ingredient as the INCI name Phenylbenzimidazole Sulfonic Acid printed on the label. Because it is water-soluble, it usually appears in the water-phase part of an ingredient list rather than among the oils.

Sunscreens with Phenylbenzimidazole Sulfonic Acid

We rate 1024 sunscreens that contain it, showing the top 10 by overall score:

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