What is SPF (sun protection factor)?
SPF is determined in the U.S. by a guideline accepted by sunscreen manufacturers and the Food and Drug Administration (FDA). This number has to do with the length of time a product protects the skin from the damage caused by ultraviolet rays, compared to how long it would take without the product. For maximum effectiveness, skincare specialists recommend applying sunscreen liberally and frequently, especially if exposed to water, perspiration, clothing or otherwise removed. The FDA recommends using a sunscreen with an SPF higher than 15 that insures broadband protection against UVA and UVB rays and contains an antioxidant. An SPF of 15 blocks out 93% of harmful rays – an SPF of 25 about 96%. In reality, the “healthy” look of tanned skin is actually the look of sun-damaged skin.
