Aug 08 2008
What is SPF?
SPF stands for Sun Protection Factor. Sunscreens are rated or classified by the strength of their SPF. The SPF numbers on the packaging can range from as low as 2 to as high as 60. These numbers refer to the product’s ability to screen or block out the sun’s burning rays, The sunscreen SPF rating is calculated by comparing the amount of time needed to produce a sunburn on protected skin to the amount of time needed to cause a sunburn on unprotected skin. For example, if a sunscreen is rated SPF 2 and a fair-skinned person who would normally turn red after ten minutes of exposure in the sun uses the product, it would take twenty minutes of exposure for the skin to turn red.
