Light stabilizers have different functions due to their different structures and varieties. Some can shield, reflect or absorb ultraviolet rays and convert them into harmless heat; Some can quench the excited state of molecules or groups excited by ultraviolet light, make them return to the ground state, and eliminate or slow down the possibility of photoredox reaction; Some capture free radicals generated by photooxidation and reduction, thus preventing the free radical reaction that leads to aging of products, and protecting products from UV damage.

To effectively prevent and retard light aging in industry, more than two kinds of light stabilizers with different action mechanisms are used to absorb ultraviolet rays at different wavelengths. It can achieve the best effect that a single light stabilizer cannot achieve.

The sunscreen mechanism of the ultraviolet absorbent added in the sunscreen cosmetics is also based on dispersing or absorbing the ultraviolet rays incident on the skin surface, so that the skin can avoid or reduce UV damage.