What Using A Sunblock Will Really Get YouAnne Tergesen
After years of equating a tan with good health, Americans are running for cover. Thanks to new Food & Drug Administration rules issued in May, now they're also learning just how much cover sunscreen products really provide.
No sunscreen offers perfect protection. So the agency barred such terms as "sunblock," "waterproof," and "all-day protection." Products can claim to be "water resistant" if they last for 40 minutes in water and "very water resistant" if they hold up for 80 minutes.
In part because a product labeled 40 filters only a tiny bit more cancer-causing ultraviolet B rays than one labeled 30--97.5% vs. 97%--the FDA capped the highest rating at "30-plus." Companies have two years to comply.
The FDA has yet to devise ways of measuring how well sunscreens filter out ultraviolet A light. While less powerful than UVB, UVA also is linked to skin cancer. Dermatologists say titanium dioxide, zinc oxide, methoxy cinnamate, and avobenzone (or Parsol 1789) stop UVA--so you should check sunscreens for these ingredients. But such products generally need to be reapplied at two- rather than four-hour intervals.
For maximum protection, coat yourself 15 to 30 minutes before going outside. Don't skimp. Most people apply only half the one ounce (or two tablespoons) recommended for full body coverage. So, "when they use a 30, they are probably only getting a 15," says Mark Naylor, associate dermatology professor at the University of Oklahoma. The American Academy of Dermatology recommends that everyone use at least a 15--even in the shade and in winter. That includes African Americans, whose rate of melanoma is one-fifteenth that of Caucasians. Those who have light skin and burn easily should use 30-plus.
Finally, don't rely on sunscreen alone. "Some rays do get through, and over time damage builds up," says Dr. Robert DeLap, an FDA office director. Wear wide-brimmed hats, ample clothing, and sunglasses. And stay indoors between 10 a.m. and 2 p.m., when the sun is strongest. Getting out of the sun still is the best protection.