rectangular ironing board cover_plastic sheet for dining table

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).

Titanium Dioxide is one of the two members of the elite sunscreen group called physical sunscreens (or inorganic sunscreens if you’re a science geek and want to be precise).