Sunscreen 101

Aug. 24, 2007 — -- Protecting your skin from the sun's damaging rays is crucial. More than 1 million new cases of skin cancer will be diagnosed in the United States this year alone.

Now the FDA has announced a new ratings system for sunscreens that could block as much as twice the sun damage.

Ultraviolet rays from the sun are the leading cause of skin cancer, the most common type of cancer in the United States.

There are two types of UV rays: UVA rays, responsible for tanning and skin damage, and UVB rays, which cause burning. Both kinds of ultraviolet rays are equally dangerous.

Until now, only UVB rays were accounted for in the sunscreen SPF factor. The new system will rate sunscreen on a four-star system, with a grade of four stars representing the highest level of protection from UVA rays.