What’s in Your Sunscreen?
Sunbathers headed to the beach this summer will find new sunscreen labels on store shelves that are designed to make the products more effective and easier to use. But despite those long-awaited changes, many sunscreens continue to carry SPF ratings that some experts consider misleading and potentially dangerous, according to a consumer watchdog group.
A survey of 1,400 sunscreen products by the Environmental Working Group finds that most products meet new federal requirements put in place last December. The rules from the Food and Drug Administration ban terms like "waterproof," which regulators consider misleading, and require that sunscreens filter out both ultraviolet A and B rays. Previously some products only blocked UVB rays, which cause most sunburn, while providing little protection against UVA rays that pose the greatest risk of skin cancer and wrinkles.
Despite that broader protection, one in seven products reviewed by the watchdog group boasted sun protection factor, or SPF, ratings above 50, which have long been viewed with skepticism by experts. In part, that’s because SPF numbers like 100 or 150 can give users a false sense of security, leading them to stay in the sun long after the lotion has stopped protecting their skin.
Many consumers assume that SPF 100 is twice as effective as SPF 50, but dermatologists say the difference between the two is actually negligible. Where an SPF 50 product might protect against 97 percent of sunburn-causing rays, an SPF 100 product might block 98.5 percent of those rays.
"The high SPF numbers are just a gimmick," says Marianne Berwick, professor of epidemiology at the University of New Mexico. "Most people really don’t need more than an SPF 30 and they should reapply it every couple of hours." Berwick says sunscreen should be used in combination with hats, clothing and shade, which provide better protection against ultraviolet radiation.
Some dermatologists say there may be some rationale for using higher SPF sunscreens, since users often don’t apply enough of the lotion to get its full effect.
"The challenge is that beyond 50 the increase in UV protection is relatively small," says Dr. Henry Lim, chair of dermatology at the Henry Ford Hospital in Detroit.
The SPF number indicates the amount of sun exposure needed to cause sunburn on sunscreen-protected skin compared with unprotected skin. For example, a SPF rating of 30 means it would take the person 30 times longer to burn wearing sunscreen than with exposed skin.