Now that we're quickly approaching the kickoff to summer, all of my posts this week will be about sunscreen. First topic: What the heck does SPF mean? We see it on sunscreens, moisturizers and even makeup. But does higher mean better sun protection? Or more time in the sun without burning? Here's the deal:
SPF stands for Sun Protection Factor. This factor is a measure of how much ultraviolet (or UV) radiation it takes to burn your skin when it's unprotected compared to how much it takes to burn it when it's slathered in sunscreen. The higher the SPF value of your sunscreen, the more protection it offers from sunburn.
Now, here's the tricky part. Many people think that SPF relates to how much time you can spend in the sun. In other words, if you can stay in the sun for 30 minutes before burning and you wear a sunscreen with an SPF of 10, you should be able to stay in the sun for 30 x 10 = 300 minutes or 5 hours before burning. Right? Not quite. Lower SPF products don't block out as much of the sun's rays as higher SPF products. Also, if you are in the sun during peak hours, you will burn more quickly. And finally, lab testing shows that people don't apply enough sunscreen to get the full SPF effect (you need to apply liberally!). So that SPF 10 product will likely only protect you for an hour (max!) - not the 5 hours that you would think.
SPF doesn't just relate to the duration of sun exposure; it also relates to the intensity of sun exposure. Here are the two factors to keep in mind when thinking about SPF.
- Time is one factor that contributes to the total exposure level but it's not the ONLY factor.
- The intensity of the UV radiation also impacts the amount. For example, one hour of sunlight at 9:00 in the morning is equivalent to 15 minutes of sunlight at 1:00 in the afternoon. So if you're only looking at how long you're out in the sun you might drastically underestimate how much sun exposure you're really getting.
Use a broad spectrum sunscreen (protects you from both UVA and UVB rays) with a minimum SPF 30. Additionally, the FDA recommends that you reapply every two hours (even if it's a waterproof or sweatproof sunscreen) and limit time in the sun, especially between 10am and 2pm when the sun's rays are the strongest. Here's to a fun and sunburn-free summer!
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3 Steps to a Sexy Summer Body --
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