How Much SPF Do I Really Need in My Sunscreen?
Last updated: September 2020
When it comes to protecting myself from dangerous things, I tend to be super safe (go overboard). Recently, I have tended to purposely avoid being within ten feet (or more) of people, when possible. When I am exercising on a local bike path, I will circle around others and go way off the path and even the beaten path to avoid possible danger. Since I am trying to get my steps in, this adds to my total and I feel better on many accounts.
Maximum sun protection
When it comes to protecting my skin, I act the same way. I was at the beach on Long Island this past weekend and while everyone was in the bathing suits and shorts at 7pm, I was still in a lightweight, long-sleeved athleisure suit with my Dodger hat. I had sunscreen on too, and the sun was going down! So, when it comes to sunscreen, I want the best product available. I want max protection.
What is the best SPF for skin cancer prevention?
The question then becomes, what really is maximum protection and when is too much not needed. Oh, I remember the suntan baking oils of the 1970s and 1980s with a Sun Protection Factor (SPF) of TWO. What was the point of that? But, how much do I really need now? SPF 10? 20? 30? 50? 100? 7,000,000?
I have been living under the assumption that my fair skin can start to burn in about ten minutes if left unprotected in direct sunlight. According to the Skin Cancer Foundation, this means that if I properly apply SPF 30 I should have 300 more minutes of sun protection from UVB rays, than if I had nothing on my skin.1 That is (wait, let me get out my trusty pocket phone calculator) five hours of protection. That’s more than enough for me since I rarely spend even a fraction of that amount of time in the sun.
This got me to thinking about SPF 100 and 1000 minutes of protection if applied (and reapplied) correctly. That’s over sixteen hours of protection. How long is the sun out on the longest day? I know that I never am out in the sun that long, but maybe some folks are.
Does the quality of SPF differ?
So, is SPF just about the time the in sun or does it relate to the quality of protection as well? According to New York board-certified dermatologist, Dr. Robin Gmyrek, properly applied SPF 15 sunscreen blocks out 93% of the sun’s burning UVB rays, while SPF 30 blocks out 97%. SPF 100 blocks out 99%.2 So, let me get this right. If I use SPF 100 properly I can stay out all day in the sun and block out 99% of the harmful sun’s rays?
SPF 100 is the most protective
So, it seems that SPF 100 is 2% better, if applied correctly and will protect longer. Dr. Gmyrek points out that over time, day after day, this does make a difference.2 So, the choice is yours. SPF 100 can be more expensive and may feel slightly different on your skin that other protection levels, so it might not be what you want. As for me, I will keep a bottle in my stash and pull it out as needed.
So, if you see a man making a point to avoid you on the bike path with a bottle of SPF 100 sunscreen hanging out of his pocket, it just could be me.
Do you sunscreen in the fall?