SPF: What Do All Of The Numbers Mean?
You know the feeling. The sunscreen aisle in the drugstore appears to be growing out of control with new types and SPF numbers every year. Recently the New York Times reported how sunscreen protection numbers have finally made it to the triple digits. SPF 100 is now available by Neutrogena beating Banana Boat which last year brought out their SPF 85 skin spray.
The SPF number is not an indicator of the percent of protection which can mislead people into thinking they are more protected than they are. SPF stands for Sun Protection Factor which indicates how much protection one receives from the UVB (ultraviolet B) sunburn causing radiation.
If a person would normally develop a sunburn in 15 minutes, SPF 15 in theory gives you 15 times more protection or up to 3 ½ hours without burning. However, people usually do not put on enough sunscreen, water or sweat may wash it away or clothes can rub it off so, in reality, we are not adequately protected for nearly that long.
The SPF number only refers to UVB protection not UVA radiation protection which until recently wasn’t available in sunscreens. Both types of radiation are thought to contribute to skin cancer but UVA affects premature aging and wrinkling as well.
The SPF 100 product seems enticing because it is capable of blocking 99% of the UVB rays however SPF 50 blocks 98% and SPF 30 blocks 96.7%. The key is to reapply in appropriate amounts much more frequently than we do.
Newer sunscreens contain products to block both UVB and UVA rays making them worth looking into. Neutrogena’s Helioplex contains Avobenzone and Oxybenzone and other sunscreens labeled “Broad spectrum” may have products like Parazol 1789, zinc oxide, titanium oxide or Anthelios SX to block UVA rays.
Tips for Buying and Using Sunscreen:
1. Buy brands that are above SPF 30 but SPF 100 is probably unnecessary. Use sunscreen 365 days a year, not just in summer.
2. Apply the equivalent of a “shot” glass or a full ounce to all exposed areas and reapply every 2-4 hrs. This means buying a lot more tubes of sunscreen and not just spreading it on once assuming you are protected.
We value and respect the experiences of all of our HERWriters, but everyone is different. Many of our writers are speaking from personal experience, and what's worked for them may not work for you. Their articles are not a substitute for medical advice although we hope you can gain knowledge from their insight.
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Thanks for these links, Alison!
One of my kids has skin very much like me - naturally very pale but can go really dark in the sun.
I put Factor 50 on her all the time and reapply often yet every summer she tans! Last year, I applied it without fail yet I noticed she had tan lines when she was taking a bath- the outline being her swimsuit, even if I use the waterproof kind and apply it every two hours!
I wonder if she is just destined to have a summer tan?
May 24, 2009 - 9:30amThis Comment
My son body surfs in the ocean so using sunscreen is very difficult. There are a number of styles of sunscreen shirts that I highly reccommend and that is what I have him wear at the beach. This is the link to LL bean but surf shops sell the kinds too that can be worn in the water.
http://www.llbean.com/webapp/wcs/stores/servlet/LLBSearchDispatch?storeI...
May 24, 2009 - 8:22pmi really , i mean really appriciate your article. God Bless ya dear, i read it word by word. Thanks :X I love U
September 18, 2011 - 11:45am