Mirror, Mirror: Putting More Protection in Sunscreen

July 21, 2010

The Philadelphia Inquirer

An article in The Philadelphia Inquirer looks at the differences in UVA and UVB sunscreens. "These sunscreens with UVA blockers are called broad-spectrum sunscreens," said William James, MD, professor of Dermatology. "This is very important for efficient UVA protection. UVB protection is just not enough." But is there a big difference between SPF 30 and a 75? Not really. The SPF - sun protection factor - generally measures how long you can stay out in the sun before burning. An SPF of 15, for example, means you are protected up to 15 times longer than you would be sans sunscreen (if you don't go swimming or sweat). And then there are those UVB rays. According to James, an SPF of 15 blocks about 93 percent of the UVB rays and an SPF of 30 blocks about 97 percent. Read More