In Southern California, we learn early in life that it’s a good idea to use sunscreen. If we’re fair-skinned we learn because we burn, and if not we learn because everyone knows someone who’s had bits of cancer cut off. Ours is a sun-seeking culture. We love the beach and being bronzed. A lot of us even go to tanning booths when it’s winter.
The Baby Boomers among us learned the hard way that sunscreen is an especially important element of any beauty regimen. Today we know that baby oil and sun reflectors are not doing us any favors.
Most of us now know we should use sunscreen, but we know little else about the stuff. We buy a sunscreen because it’s been marketed well or because we like how the bottle looks. It’s important, though, for us to be aware of what the products in our beach bags are doing to and for our skin.
I’ll talk about the SPF number first. This refers to a sunscreen’s Sun Protection Factor—a measure of its effectiveness at protecting your skin from UVA and UVB rays.
UV radiation is part of the light spectrum generated by the sun, and comprised of short- and long electromagnetic wavelengths. UVA and UVB are the only rays that reach the earth through the atmosphere. UVA is the longest kind of ray and burns the deepest; it can penetrate your skin’s thickest layer. Still, both UVA and UVB can burn your skin, giving you wrinkles, cancer, or both. Older computer screens emit UV radiation, too, so if you’re using one, make sure you’re wearing sunscreen anytime you jump on the internet. Research shows the newer-model screens (LED and LCD) are safe.
A product with a higher SPF offers more protection against UVA and UVB rays, though studies show anything higher than 50 is just a marketing ploy. According to published research, SPF 15 filters out about 93 percent of ultraviolent rays, SPF 30 filters 97 percent, and 50 filters 99 percent.
Sunscreens can come in physical or chemical forms. Physical sunscreen is the thick liquid most of us are used to, and contains ingredients like zinc oxide that block the sun’s rays from penetrating the layers of our skin. Chemical sunscreens, on the other hand, contain ingredients like oxybenzone which produce reactions that convert radiation to heat, which doesn’t damage the skin.