Last week we spoke about extrinsic aging and the damage the sun can do to your skin. Although, it not possible to reverse the actual DNA damage that has already been done, it is possible to protect your skin from more.
SPF stands for Sun Protection Factor. It indicates a sunscreen’s ability to block UVB rays.
The number of SPF is an approximation of the time a person who has applied the sunscreen can stay out in the sun without getting burned using the following equation:
Take the time you would normally burn in the sun without protection, 20 minutes will normally produce redness on a light skinned individual.
Multiply this number by the SPF of your product. Example: with an SPF 15 x 20 minutes of sun time = 300 … is how many minutes you can stay in the sun without burning. 300 minutes divided by 1 hour of 60 minutes = 5 hours of sun protection without a sunburn if your sunscreen is properly applied.
This equation is not perfect because the amount of UV light that reaches us depends on a number of factors, including cloud cover, the time of day, and the reflection of UV rays off the ground, water, sand, etc., so it’s generally recommended that you reapply sunscreen every two hours (or even sooner).
Above, I mentioned “if applied properly” and, believe it or not, most of us don’t apply our SPF properly, or often enough. Here are some tips to help your get this right
1. Use a broad-spectrum sunscreen, it protects skin from both UVA and UVB rays
2. Apply at least shot glass full of sunscreen to ALL exposed areas at least 15 minutes before going out in the sun.
3. Reapply every 2 hours. After the initial application you can use a sunscreen powder (for oily skin) or a sunscreen mist (for dry skin). If you are at the beach or anywhere else sitting in the sun, reapply your regular sunscreen.
4. Use a lip balm with an SPF of 30.
5. Reapply sunscreen after swimming or sweating, water resistant doesn’t mean waterproof
6. Water, snow and sand reflect UV rays, increasing your chances of burning, use extra care.
7. Don’t use expired sunscreen or sunscreen left in a hot car, it won’t be effective anymore.
To learn more about the different types of sunscreens, and how to protect your skin from damaging UV rays, check out our Episode 22 of the Beauty in Aging Podcast. We’re on all the platforms, here are just a few: