Experts' tips for choosing the safest sunscreen
5/23/2017, 7:56 p.m.
(CNN) Throughout the summer, consumers struggle with how to best protect their skin from the harmful rays of the sun. But which products are the safest?
A new report released Tuesday by the Environmental Working Group claims that 73% of the 880 sunscreens it tested don't work as well as advertised or contain "worrisome" ingredients. The authors of the annual report say they hope to help consumers make smarter choices when choosing the right products -- because not all sunscreens are made equal.
"Sunscreens are really mismarketed, and as a result, people who depend on them think they are far more powerful than they really are," said Sonya Lunder, a senior analyst with the environmental advocacy group and lead scientist of the 2017 Sunscreens Guide.
After examining the SPF protection, chemical ingredients and overall safety and effectiveness of several sunscreens, moisturizers and lip balms, the advocacy group compiled a list of its best- and worst-rated products.
A guide released this month by Consumer Reports also rated sunscreen products for safety, UV protection, water resistance and cost. Of the 58 products tested, researchers named 15 that met their standards. Twenty were found to offer less SPF protection than advertised.
How high is too high?
Dermatologists recommend using sunscreen to block the sun's ultraviolet rays. Both of the two types of UV rays can cause skin cancer. A UVA ray, the longer wave of the two, penetrates the skin deeply and is less likely to burn and show signs of overexposure. UVB rays are shorter and tend to damage the outer layer of the skin, causing sunburn. Both are linked to melanoma and other skin cancers. Most sunscreens sold today help protect against both.
The phrase "broad spectrum" signifies that a sunscreen offers some protection from UVA rays. The Sun Protection Factor (SPF) number is the level of protection a sunscreen provides against UVB rays, waves of light from the sun that are damaging to the outer surface of the skin.
Dr. Dawn Davis, a dermatologist at the Mayo Clinic who was not involved in the new reports, says SPF is a ratio of how long a person without sunscreen can be in the sun without experiencing any redness divided by the amount of time you can spend in sunlight with a product on.
In other words, "if you're standing on the equator at high noon and it would usually take your skin one minute without sunscreen to become red and irritated, SPF 15 means you can stand in that same sun exposure for 15 minutes."
But SPF 15 may not be enough for extended coverage. The American Academy of Dermatology recommends choosing a sunscreen that is at least SPF 30, which would block 97% of UVB rays.
So more is better, right? Not so fast, says Lunder. Several brands offer products with a high SPF, even over 100. But, she says, consumers are not getting the protection they think they are.
"People who buy high-SPF products are more likely to get burned because they assume they're getting better and longer-lasting protection," she said. Maximum protection comes when sunscreen is reapplied every few hours, and Lunder says people who buy these high-SPF products do not reapply often enough to have continuous skin protection. She recommends sticking to products between SPF 30 and 50.