SPF stands for sun protection factor. Simply put, an SPF rating tells you how long you can stay in the sun without getting burned while wearing that sunscreen, compared with how long you can stay in the sun before you burn without wearing that sunscreen. For example, if it typically takes you 15 minutes to burn without sunscreen and you apply an SPF 10, it will take 10 times longer (2.5 hours ...
"SPF is not a consumer-friendly number," says Florida dermatologist James M. Spencer, MD. "It is logical for someone to think that an SPF of 30 is twice as good as an SPF of 15 and so on. But that ...
What Is a Good SPF Number? According to the Skin Cancer Foundation, a good SPF number depends on expected sun exposure, skin tone, age and family history of skin cancers. An SPF of 15 is generally sufficient for daily activities. For extended sun exposure, an SPF of 30 or higher is recommended.
What Does the SPF Number Mean? The SPF number tells you how long the sun’s UV radiation would take to redden your skin when using the product exactly as directed versus the amount of time without any sunscreen. So ideally, with SPF 30 it would take you 30 times longer to burn than if you weren’t wearing sunscreen.
A few years ago, choosing a good sunscreen meant you just looked for a high sun protection factor (SPF) -- which rates how well the sunscreen protects against one type of cancer-causing UV ray ...
SPF30 seems low compared to all the other SPF levels on the market. Why is this number so low? "The number means that it would take 30 times longer to burn than not wearing any sunscreen. That means if it would take a minute to burn without sunscreen, it would take 30 minutes to burn after applying the recommended amount of SPF30.
Then they redo the test with sunscreen. The "with sunscreen" number is divided by the "without sunscreen" number, and the result is rounded down to the nearest five. This is the SPF. SPF numbers start at 2 and have just recently reached 70. To figure out how long you can stay in the sun with a given SPF, use this equation:
SPF — or Sun Protection Factor — is a measure of a sunscreen's ability to prevent UVB from damaging the skin. Here's how it works: If it takes 20 minutes for your unprotected skin to start turning red, using an SPF 15 sunscreen theoretically prevents reddening 15 times longer — about five hours.
SPF stands for “sun protection factor,” and it measures your sunscreen protection from UVB rays. Think about this way: If your skin would normally burn after 10 minutes in the sun, applying an SPF 15 sunscreen would allow you to stay in the sun without burning for approximately 150 minutes (a factor of 15 times longer, hence SPF 15).
It’s sunscreen shopping season and the just-released 2012 Sunscreen Guide published by the Environmental Working Group (EWG) helps steer consumers toward healthy, affordable choices for sunscreen, lip balms and cosmetics.. Celebrate great health! LIKE BlackDoctor.org on Facebook!