Sunscreen Hazards continued...
They used to go on thick and white like an ointment for diaper rash. In fact, zinc oxide is the main ingredient in baby ointments. So they weren't the most popular sunscreens. You only saw them on lifeguards' noses.
Now there are mineral sunscreens in which the particles have been shrunk to micro or nano-size to become colorless on the skin.
Can nanoparticles get past the skin's surface and into the body? There is still debate about whether they get into the body and, if so, what effects they might have.
"You want to avoid any sunscreens that have nanoparticles," Jaliman says. "They are showing up in the liver and in the bloodstream, and they are banned in a lot of places."
However, Lim says we don't know for sure when these nanoparticles can sink below the skin's surface.
"We know that with intact skin, nanoparticles will stay on top of the skin. What is not known is if the skin is broken, for example with eczema, would nanoparticles go in? That part we don't have a good answer for," Lim says.
If you are concerned, check the labels. Look for "non-nano" under active ingredients. However, sunscreens are not required to note whether they include nanoparticles.
The AAD and the Skin Cancer Foundation have reviewed studies that suggest these ingredients are dangerous. They, along with the FDA, continue to stand behind the ingredients. The Personal Care Products Council, a trade group, also backs these ingredients.
Dermatologists emphasize that sunscreen, though essential, is just one part of sun protection. Along with sunscreen, you should also wear hats and protective SPF-rated clothing as well as seek shade during the hours of most intense sunlight.
"The more things you can do to set yourself up for success, the better," says Ellen Marmur, MD, FAAD, author of Simple Skin Beauty and vice chair of cosmetic and dermatologic surgery at New York's Mount Sinai Medical Center.
What's on the Label?
Here are some of the numbers, phrases, and instructions found on a sunscreen label.
SPF: SPF 15, for example, means it would take your skin 15 times longer to get red than if you were wearing no protection at all. So if your unprotected skin begins to redden after 10 minutes in the sun, then with a generous coat of SPF 15, it would take 150 minutes for your skin to begin to turn red, Marmur says.
But to get this protection, you'd have to slather sunscreen on as thick as icing.
"So we're really getting, say, half the number that's on the bottle so just buy the [SPF] 30," Marmur says. That's what the American Academy of Dermatology (AAD) recommends, too.
If a sunscreen has an SPF below 15 or does not offer broad-spectrum protection (protects against UVA and UVB), the new label will say that it only guards against sunburn but not skin cancer.