THE FACTS

Everyone knows that an SPF rating of 60 provides double the protection of SPF 30 — or does it?

Studies over the years have shown that sunscreen with an SPF, or sun protection factor, of 30 blocks about 97 percent of ultraviolet rays. A rating of 15 means 93 percent of UV rays are blocked, and anything higher than 30 remains in the 97 or 98 percent range.

Image Credit... Leif Parsons

In 1999 the Food and Drug Administration recommended that sunscreens with an SPF higher than 30 be labeled “30+,” mostly to prevent people from developing a false sense of security that might lead them to spend more time in the sun.