Jun 23, 2008 3:10 pm US/Eastern
SPF Confusion: The Truth Behind The Numbers
BOSTON (WBZ) ―
-
-
SPF is a universal measure of UVB rays.
WBZ
Summer means time outside, and that means it's time to apply the sunscreen. But with so many products on the market, it can get confusing.
One thing is for sure: people are getting the message that they need to apply some type of protection. As one consumer said, "I think it's important to wear sun block to stay looking young."
Another added that she is very concerned about skin cancer.
The challenge is to figure out just what type of sunscreen is right for you.
Products now offer an SPF of more than 70. SPF is a universal measure of UVB rays. Applying a product with an SPF of 15 will block about 93 percent of UVB rays, while a product with an SPF of 30 blocks 97 percent.
That surprised some consumers. Dr. Elizabeth Hale of the Skin Cancer Foundation explained, "UVB protection does not increase proportionally with SPF number."
Here's how it works. There is a large jump of an SPF of two, which blocks about 50 percent of UVB rays, and an SPF of 15. But because the increments are so small after that, some dermatologists say an SPF of 15 should do the trick for most people on a day-to-day basis. Dr. Zoe Draelos of the American Academy of Dermatology said, "This would be for casual wear. You're going to and from the car. You're putting out the garbage. You're picking up kids at the bus stop."
Doctors say one of the most important factors that people overlook is the proper application of sunscreen. Dr. Hale said that studies have shown that people in general don't use enough sunscreen. In fact, the effective SPF might be far less than what is actually seen on the bottle because people are not using enough. In most cases, it takes about the equivalent of a shot glass applied to all exposed areas to get the full benefit.
Another oversight often involves UVA protection. There is no rating scale like SPF so consumers need to be on the look out for "broad spectrum," as well as the ingredients on the label. Dr. Draelos said the most important ingredients to look for are avobenzone, titanium dioxide, and zinc oxide.
Sunscreen can last in your cabinet for several years, but Dr. Hale says having leftovers might be the sign of something else. "If it is still on your shelf, than you weren't using enough in the first place."
For the best protection, apply sunscreen 15-30 minutes before going outside, remember "waterproof" doesn't mean you can swim all day without reapplying, and make sure you do reapply every two hours.
(© MMIX, CBS Broadcasting Inc. All Rights Reserved.)
Click to enlarge
Stumble It!
Reporting
Comments