About SPF: A Primer

We’ve officially hit summer, and with the warmer temperatures, most of us are spending a lot more time outdoors.  Using sunscreen may be a given for many, but if you care about keeping your skin healthy and young-looking, it’s important to understand how the sun can cause damage and even more crucial to know how to maximize the protective power of your sunscreen.  SPF is not everything!

First up, what exactly does SPF mean?  SPF stands for Sun Protection Factor. This rating system is a measurement of the length of time a sunscreen will protect you from burning UVB rays compared to how long it would take you to burn with no protection whatsoever. For instance, if you typically burn in 10 minutes, an SPF 30 product should give you protection for 10 minutes x 30, so 300 minutes. Keep in mind that this is very much dependent on applying enough, something most of us do not do.

Another thing to keep in mind: reapplying after the recommended 2 hours does not extend your protection time by another 300 minutes. You are simply maintaining the same level of protection for the same amount of time. The SPF rating does not give any indication of the amount of protection afforded against UVA rays (those responsible for skin aging). Most dermatologists recommend choosing a sunscreen with a minimum SPF 30 (which blocks about 97% of UVB rays; an SPF 60 product blocks about 99%). Which brings us to….

Broad Spectrum. Sunscreen formulations that protect against both burning UVB rays as well as the longer, deeper penetrating UVA rays (linked with premature aging and many types of skin cancer) are known as broad spectrum. Over the last 10 years, it has become increasingly evident that UVA rays are responsible for damaging skin cells in the basal layer of the epidermis where most skin cancers occur. Unlike UVB rays, UVA rays are prevalent year round and can pass through clouds and windows, further supporting the need for sunscreen year round, regardless of weather. Lucky for you, we stock a wide selection of broad spectrum sunscreens including ever popular Mexoryl sunscreens, including Anthelios and Ombrelle.

Now that we know what type of sunscreen to choose, here are 5 tips for getting the most out of your sunscreen:

 1.    Apply 15-30 Minutes Prior to Sun Exposure:

Although applying the sunscreen upon arriving at the beach or 5 minutes before you step out the door is probably more the norm, it may not be the optimum timeframe for application. Physical sunscreens (those containing titanium dioxide or zinc oxide, like Cliniderm SPF45 Gentle Protective Lotion and Neostrata Protective Lotion SPF45) may be applied with no waiting time because they work by sitting on top of the skin and deflecting UV rays. Chemical sunscreens (those containing ingredients such as Mexoryl SX, Mexoryl XL and Tinosorb S), however, need some time to interact with the skin’s surface before reaching maximum effectiveness. Sun filters in these sunscreens work by absorbing UV rays and releasing them as harmless heat. Even if you’ve missed the 15-30 minute window, you’ll still get more protection if you put on sunscreen than if you don’t.

 2.    Apply Enough.

Studies have shown that the majority of us never apply enough sunscreen for adequate protection – the reason for sunburns and tanning despite sunscreen application. To achieve the Sun Protection Factor listed on a bottle of sunscreen, you should use approximately two milligrams of sunscreen per square centimeter of skin. In practice, this means applying the equivalent of a shot glass (two tablespoons or 1 fluid ounce) of sunscreen to the exposed areas of the face and body – a nickel-sized dollop to the face alone. I like to apply once, wait a few minutes and then apply a slightly thinner layer on top. This way I know that I haven’t missed any spots. And stretching one bottle of sunscreen over the whole summer is not the goal!

 3.    Reapply As Needed.

The advice regarding reapplication is directed towards being outside in direct light, which can break down sunscreen filters. And since most of us don’t apply enough, the reapplication advice helps to ensure that we end up with better and longer sun protection.  If the majority of your day is spent inside, your sunscreen should still be effective at the end of the day. If you are outside, however, reapply every 2 hours. You may need to reapply more often if you are swimming or sweating.  Reapplying is a must after towelling off.

 4.    Use a Water-Resistant Sunscreen if Swimming or Sweating:

Not all sunscreens are water-resistant so make sure you choose one if you need it. Water resistant sunscreens are formulated to resist being washed off by water. The industry standard for “water resistant” is effective for 40 minutes in the water. “Very water resistant” sunscreens are effective for 80 minutes in the water. However, like the sun, water also breaks down the stability and effectiveness of the sun filters, leaving you exposed to harmful rays that will not only burn but age and increase the risk for skin cancer. Washing your hands also removes sunscreen so reapply if you need to.

 5.    Don’t miss these commonly missed parts:

  • Lips
  • The part in your hair (sprays or powder sunscreens are ideal here)
  • Ears
  • Décolleté
  • Back of the neck
  • Under the chin
  • Tops of the feet
  • Hands
  • Backs of the knees