Melanoma Education Foundation
Free melanoma lessons for middle and high school students

July 20, 2017 | Stephen Fine, Founder and President

SPF: Fact versus Fiction

Each day, more people learn about the importance of wearing sunscreen whenever they’re outdoors to shield themselves against the sun’s harmful UV (ultraviolet) rays. While that news is heartening, getting that information out is only half of the battle.

If a user misunderstands how a sunscreen’s Sun Protection Factor (SPF) works, or if the product is incorrectly applied, the level of protection received can be considerably lower than he or she believes it to be. That can be very dangerous.

Here’s why:

If your mouthwash contained a lesser percentage of cinnamon flavor than you thought it did, it would make absolutely no difference as far as your health is concerned. However, if you walked around every day thinking you were wearing a sunscreen that provided more skin defense than it actually did, that mistaken notion could end up resulting in skin cancer. Or, even worse, the potentially deadly melanoma.

Don’t Get Burned, Either Literally or Figuratively

We’d like to help clear up this confusion. There is a view held by many that, because an SPF 50 sunscreen absorbs 98% of UVB radiation while an SPF 100 sunscreen absorbs 99%, just 1% more, the SPF 100 sunscreen offers hardly any advantage over the SPF 50 sunscreen. That’s a misinterpretation of the facts.

If an SPF 100 sunscreen is correctly applied and continually re-applied every two hours at a minimum, (or immediately after swimming or profuse sweating) it’ll provide adequate skin protection for double the amount of time that a SPF 50 sunscreen will.

But Wait, There’s More!

There are other ways that we inadvertently end up leaving ourselves vulnerable to those dangerous UV rays. We’ll go over a few here.

It’s the rare person who applies an amount of sunscreen sufficient enough to reach the SPF level touted by the product. And, whether they do or not, most don’t re-apply it as needed- if they even re-apply it at all.

Every time you use sunscreen, the goal should be to cover every sun-exposed inch of skin. If you’re in a swimsuit, the necessary quantity is enough to fill a shot glass. In fact, instead of guessing, consider simply using an actual shot glass.

Unfortunately, independent studies have shown that an alarming number of sunscreen brands don’t meet the SPF ratings that their packages trumpet. It’s important to do a little online research on your favorite brand to see if the claimed SPF is accurate.

Finally, it bears repeating. You’ve probably heard that famous real estate slogan, it’s all about location, location, location! With sunscreen, think re-application, re-application, re-application! If you’re going to be spending time outdoors, re-application is as important as applying sunscreen is to begin with.


*Additional source: Melanoma Education Foundation (MEF) Fall 2016 Newsletter