UV absorber
Light Stabilizer
UV filter
CAS Number(s)
EINECS number(s)

Benzophenone-4 is a white to pale yellow powder, utilized as a UV filter in sunscreen applications. Thanks to the presence of the sulfonic acid group in the structure, it is readily soluble in water, propylene glycol, glycerin, ethyl, and isopropyl alcohols.

Combined with other oil-soluble UV filters like Benzophenone-3, it can provide the highest sun protection factor (SPF) protecting the skin from the harmful influence of UV radiation. Besides sun care, Benzophenone-4 is frequently used in hair-protecting products and can be added to the formula to preserve other ingredients from UV-induced degradation.

The presence of the sulfonic acid group in the molecule makes Benzophenone-4 acidic, so it must be neutralized with one of the usual neutralizing agents like triethanolamine and sodium hydroxide. However, the neuralization can change the UV-absorption ability and color intensity of this ingredient.

Incorporated in water-based formulations, Benzophenone-4 provides excellent skin protection against sunburn. In hair care products, it prevents brittleness and protects bleached hair from the effect of UV radiation. In addition, Benzophenone-4 prevents color fading of formulations in transparent packaging, stabilizes the viscosity of gels based on polyacrylic acid, and improves the stability of fragrance oils.
5-Benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid
GalSORB Benzophenone-4