Butyl methoxydibenzoylmethane, also known as avobenzone, is an oil-soluble ingredient used in sunscreen products due to its broad-range UV protection and ability to block UVA and UVB wavelengths. UV absorbers are also known as chemical sunscreen ingredients, which work by absorbing UV light and then transforming that light energy into some other form of energy, such as heat. This is in contrast to physical sunscreens, which protect skin by using physical UV filters to block or deflect UV light.
One advantage chemical sunscreens have over physical sunscreens is their ability to be absorbed into the skin, which allows them to defend the deeper layers of skin, including collagen fibers and other tissue, against the aging effects of UVA rays. Furthermore, skin absorption enables chemical sunscreens to prevent penetration by the UVB rays responsible for tanning and sunburn. A drawback of chemical sunscreens, however, is that they rub off more easily since they are thinner and must be reapplied more frequently. Another issue with butyl methoxydibenzoylmethane is that it breaks down in the presence of sunlight. Therefore, manufacturers must combine it with other ingredients, known as photostabilizers, that prevent it from breaking down.