The ABC’s of SPF—Basics for Preventing Sun Damage

When it comes to your skin, there are few cosmetic skin treatments that are more important—or more impactful—on preventing sun damage than wearing sunscreen.  And even though you can find sunscreen on the shelves of nearly every drug store, grocery, and dollar store between here and Dewey Beach, all sunscreens don’t work the same way.  So to ensure you are protecting your skin as thoroughly as possible from harmful UV rays while vacationing this summer, keep these essentials in mind when packing your beach bags.

#1. 15? 30? 50? What does that number really mean? The SPF (Sun Protection Factor) number of your sunscreen is a measure of how well the product blocks harmful UVA and UVB rays from the skin. It’s also a measure of how long that particular product will protect your skin from the sun’s damaging rays. To figure out how long an SPF will work for you, simply time how long you can be in the sun—with no sun protection—before burning, and then multiply that number by the SPF number on your bottle.

For example, if you can be in the sun for ten minutes (with no sun protection) before burning, and you have a product with SPF15, multiple 15 x 10 = 150, which means after you have applied the product, you can be in the sun for 150 minutes, or almost two hours, before you need to re-apply. 

However, and here is where it gets tricky,  according to the Skin Cancer Foundation, no sunscreen can be expected to stay effective for longer than two hours without reapplication. So, even if you are using an SPF 50, and following the formula above, could stay out in the sun for 6 hours before burning—you still need to reapply every two hours to be truly protected against sun damage.

#2. Chemical or physical ingredients: is that really important?  The short answer is yes!  The choice to use a chemical or physical sunscreen is largely personal preference, but in order to be sure you are using each of these products correctly, you need to know why they are different, and how they work.  Chemical sunscreens protect against sun damage with chemical ingredients such as Avobenzone, Octocrylene, or Homosalate, which absorb UV rays as they penetrate the skin. Chemical sunscreens must be applied to the skin at least 20 minutes before you plan on being outside in order for the chemical to provide true sun protection.

On the other hand are physical sunscreens, which are made from ingredients such as zinc oxide or titanium oxide, and often appear white or pasty on the skin (think how a life guard’s nose looks at the pool!) Instead of absorbing the sun’s rays, physical sunscreens reflect them away from the skin, sort-of like a mirror. And, physical sunscreens do not need to be applied before you go outside in order to provide protection: as soon as this kind of sunscreen is on the skin, the skin is protected.

#3. I don’t burn; why do I need to wear sunscreen?  No matter what kind of exposure you get from the sun, the end result is the same for your skin: sun damage.  And even if that damage doesn’t look like sunburn on your particular skin tone (people who say “I never burn!”, I’m looking at you), it can still lead to the most deadly form of skin cancer around: melanoma.  Darker skin tones may not be at risk for sunburn as quickly as someone who has a lighter tone, but everyone should be wearing sunscreen—every single time they are outside in the sun because all skin tones can burn. Period. 

#4. What is the difference between UVA and UVB rays?  Both UVA and UVB are rays from the sun that can (and usually do) cause trouble for the skin. UVA rays refer to the rays that prematurely ‘age’ the skin, and hasten the appearance of sun-related damage such as dark spots, fine lines and wrinkles.  UVB rays refer to rays that ‘burn’ the skin, and increase your risk for skin cancer.  To ensure you are fully protected, select a sunscreen or sunblock that offers broad-spectrum protection, which means it blocks both types of UV rays.

#5: What else can I do to protect myself from sun damage? 

Follow these tried-and-true rules.

  • When you aren’t swimming or in the water, either stay indoors or find shade, particularly between the hours of 10am – 2pm, when sun is at its most ferocious.
  • Wear a hat, large sunglasses, and if you are planning on being outdoors all day, consider bringing a long-sleeve shirt and pants.  There are many options available that are incredibly light weight and breathable, plus; some fabrics are even impregnated with SPF, as well.
  • Re-apply sunscreen every two hours, especially if you have been swimming or sweating.  No excuses!
  • Apply sunscreen thickly and over every area of exposed skin, including behind the ears, and on the top of your head (particularly important for men who shave their heads).  To adequately cover the entire body, you need at least 1 ounce of sunscreen , which is about the size of a full shot glass.
  • Don’t forget to hydrate! In addition to protecting your skin from the outside in, do something good for it from the inside out when you are spending the day pool or beachside: drink plenty of water.  
Posted on August 2, 2016 .