Understanding the active ingredients in sunscreen is a bit like learning a foreign language that uses a different alphabet. Suffice it to say in short that sunscreens are made up of a combination of two types of ingredients: those that reflect ultraviolet (UV) rays and those that absorb UV rays. Although that might sound simple enough, there are also two types of rays: UVA rays and UVB rays. UVB causes sunburn at the outer layers of skin, but UVA causes sun damage that reach deeper layers of skin. Both UVA and UVB radiation can contribute to the development of skin cancer. Avobenzone is an oil soluble ingredient found in many sunscreen products that effectively absorbs the full spectrum of UVA light from the sun. It unfortunately degrades after a few hours in the sun. However, some advanced sunscreen formulations using special compounds to stabilize avobenzone can provide effective UVA protection. Avobenzone is currently approved worldwide. Its ability to intercept a wide range of UV light has led to its use in many commercial sun protection products marketed as “broad spectrum” sunscreens. Keep in mind that a sunscreen’s Sun Protection Factor (SPF) is a gauge of how well the formula protects the skin from UVB rays. It does not gauge protection from UVA rays.