Sunscreen SPF

Sun Protection Factor (SPF) is a measurement of how well a sunscreen will protect skin from UVB rays (radiation that causes sunburn). Here is an example… if you would normally burn after 10 minutes in the sun, then wearing an SPF 15 sunscreen would theoretically allow you to stay in the sun for ten times that amount (150 minutes) without burning. Your mileage may vary, depending on the type of activity you do, and the intensity of sunlight, and the amount of sunscreen you apply.

The American Cancer Society recommends that people use a sunscreen of at least SPF 15. Higher SPFs will give you more protection, but one thing to keep in mind when picking a sunscreen is that SPF 50 does not prevent burns forty percent longer than a SPF 30. In fact SPF 50 blocks only about 1.3% more UVB radiation than SPF 30. Tests have shown that SPF 15 sunscreens filter out 93% of UVB rays, while SPF 30 protects against 97%, and SPF 50 98%. One other thing to note is that the rating tells you about UVB protection, and not about protection from UVA rays, which are also harmful.

More important than seeking out ultra-high SPF products is that you apply your sunscreen generously – most people put on less than half enough sunscreen to actually reach the product’s SPF rating. With proper usage of an SPF 50 sunscreen you should be able to get more than ten times the solar exposure before burning had you not been wearing sunscreen. Proper usage ensures that you are applying sunscreen 20-30 minutes before solar exposure, applying one ounce for your entire body, and reapplying frequently. Make sure to reapply every two hours, and after swimming, sweating, or toweling off.