What Is a Sun Protection Factor?
The Sun Protection Factor is a measurement of a sunscreen's ability to limit the skin's exposure to the sun. An SPF 15 sunscreen keeps 93 percent of all harmful ultraviolet B (UVB) rays from affecting the skin. Products with SPF levels of less than 15 allow more UVB to reach the skin. For example, an SPF 4 sunscreen protects skin from about 75 percent of UVB. Many sunscreens on the market today provide protection from a second form of UV called ultraviolet A (UVA) as well. Sunscreens that offer both UVA and UVB protection are labeled as "broad-spectrum" formulas.
Selecting the Best SPF
Most dermatologists agree that adults and children should use a sunscreen with an SPF level of at least 15 to get adequate protection from the sun. Sunscreens that have SPF levels below 15 are typically used by people who want basic protection. Other people may need or want a sunscreen with an SPF level above 15. A doctor can give you specific advice to help you select the best SPF level for your skin.
Choose the Right Form
Sunscreens with SPF levels of 15 and below are offered in many forms. You can find moisturizers with SPF protection to use for daily facial sun protection and a variety of options for applying from head to toe when you'll be outdoors. Options include easy-to-measure lotions and gels and simple-to-apply sprays and sticks.
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