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Posts Tagged “spf”

May 14 2009

The 411 on SPF

Posted by DDOCS in Gimmicks, Marketing, tags: Marketing, spf, sun

As we gear up for fun in the sun this summer, you might find yourself stocking up on sunscreen. The drugstore shelves are crammed full of choices that offer various levels of protection against the sun’s rays. SPF 15, 30, 45, 60, 85…. How are we expected to make heads or tails of it all? Today’s New York Times does a good job breaking down the mystery of SPF.

Popular sunscreen makers, such as Banana Boat, Coppertone, and Neutrogena, keep raising the SPF numbers in their products. There is now a sunscreen with an SPF of 100. We’re conditioned to believe more is better, but does the higher SPF number mean it offers superior protection? No, according to experts. It’s really nothing more than a marketing gimmick.

The difference in UVB protection between an SPF 100 and SPF 50 is marginal. Far from offering double the blockage, SPF 100 blocks 99 percent of UVB rays, while SPF 50 blocks 98 percent. (SPF 30, that old-timer, holds its own, deflecting 96.7 percent).

So, what does matter when it comes to sunscreen?

How much sunscreen you actually apply. A shot glass full of sunscreen is what should be used to cover the entire body. If you skimp on that, you dramatically reduce the sun protection offered by the sunscreen. For example, if you use SPF 70 but only apply half the recommended amount, you’re not getting SPF 35. Rather, you are getting the square root of SPF 70, which is 8.4.

The amount of time spent in the sun. You can’t slather on SPF 50 in the morning and go all day without reapplying. Most sunscreens recommend a refresher application every 2 hours, more often if you’ve been sweating or in the water.

The UVB and UVA protection offered in the sunscreen. According to the article, “both UVA and UVB radiation can lead to skin cancer, which is why dermatologists now advise using sunscreens with an SPF of at least 15 and UVA-fighting ingredients like an avobenzone that doesn’t degrade in light or Mexoryl SX.”