As the season of bare skin and scorching sun draws near, you — like so many other people — may find yourself scratching your head over sunscreen.
Yes, skin protection is essential, especially with skin cancer rates on the rise in many populations around the world. But sunscreens come with often confusing labels and long, unpronounceable lists of chemical and other ingredients. How do you know which are safe to slather on you or your kids?
The first thing to keep in mind is that not all sunscreens are created equal, says Mary Sheu, an assistant professor of dermatology at the Johns Hopkins School of Medicine.
"There are physical sunscreens that reflect light — they're like little mirrors that sit on your skin," she says. Such products, made with zinc oxide or titanium dioxide, sit on your skin and block the sun's UVA and UVB rays. (These are the ones that can cause sunburns, cell damage and skin cancer.)
The minerals are opaque, giving beachgoers that classic white-nose look, though new versions are often tinted or "micronized" (ground into tinier-than-usual particles) so they'll blend into the skin.
Physical sunscreens are the least likely to produce rashes or other allergic reactions, so they're often recommended for people with sensitive skin, Sheu says.
The other kind of protection is chemical sunscreen. Instead of blocking or reflecting the sun's rays, these products absorb UVA and UVB light to keep it from damaging skin, Sheu says. Unlike physical sunscreens, they can be absorbed into the skin — and that's where the question of safety comes in.
"Even though the data are soft, we do know that a certain amount of the chemical sunscreens are absorbed into the body, and we don't know exactly what their effects are," says Robert Friedman, a clinical professor of dermatology at the New York University School of Medicine and the chief executive of MDSolarSciences, a company based in Norwalk, Conn., that develops sunscreen and skin-care products.