Traditionally, UV-filters are categorized as either chemical or physical. The big difference is supposed to be that chemical agents absorb UV-light while physical agents reflect it like a bunch of mini umbrellas on top of the skin. While this categorization is easy and logical it turns out it's not true. A recent, 2016 study shows that inorganic sunscreens work mostly by absorption, just like chemical filters, and only a little bit by reflection (they do reflect the light in the visible spectrum, but mostly absorb in the UV spectrum).

One of the main challenges that manufacturers face when it comes to buff percentage is ensuring consistency. Variations in the level of coating on titanium dioxide particles can lead to differences in color, opacity, and other properties in the final product. This can be especially problematic in industries such as paint and coatings, where consistency is critical for achieving the desired results.

Titanium dioxide (TiO₂) is a multifunctional semiconductor that exists in three crystalline forms: anatase, rutile, and brookite. Owing to an appropriate combination of physical and chemical properties, environmental compatibility, and low production cost, polycrystalline TiO₂ has found a large variety of applications and is considered to be a promising material for future technologies. One of the most distinctive physical properties of this material is its high photocatalytic activity (Nam et al., 2019); however, more recently it has attracted growing interest because of its resistive switching abilities (Yang et al., 2008).

Other food manufacturers use titanium dioxide to absorb water and keep moisture from clumping or degrading, Paul Westerhoff, PhD, an environmental engineer at Arizona State University who researches the biological and cellular effects of titanium dioxide, told Health.