Last year, Coppertone rolled out two easy-to-use sprays with its highest-ever sun protection factor: SPF 70+. Not to be outdone, Neutrogena offered its Ultra Sheer Dry-Touch lotion in SPF 85 strength, that year’s big gun.
This sun season, Banana Boat is retaliating with a pair of SPF 85 sprays, which it trumpets on its Web site as “our highest SPF level in a continuous spray formula.”
But now, SPF creep has hit the triple digits with Neutrogena’s SPF 100+ sunblock, leading some dermatologists to complain that this is merely a numbers game that confuses consumers.
The parade of stratospheric SPFs is “crazy,” said Dr. Barbara A. Gilchrest, a dermatology professor at Boston University School of Medicine. “For a normal person who is fair-skinned and concerned about skin damage and photoaging,” Dr. Gilchrest said, “it’s really in my opinion tremendous overkill.”
A sunscreen’s SPF number is calculated by comparing the time needed for a person to burn unprotected with how long it takes for that person to burn wearing sunscreen. So a person who turns red after 20 minutes of unprotected sun exposure is theoretically protected 15 times longer if they adequately apply SPF 15. Because a lot of sunscreens rub off or don’t stay put, dermatologists advise reapplication every two hours or after swimming or sweating.
“As you get higher and higher, it’s not really a practical difference,” said Dr. David M. Pariser, the president of the American Academy of Dermatology.
Consumers should worry more about wearing enough sunscreen, several doctors said, rather than how high their SPF is.
Skimp and you lose. To get the SPF advertised, you must use a full shot glass on your body. That’s an ounce, which means a three-ounce tube should last, at most, a few outings.