Does the best sunscreen also have the highest SPF?
SPF stands for sun protection factor. This is a measure of how well the sunscreen deflects UVB rays. Currently, there’s no standard for measuring UVA protection. Manufacturers calculate SPF based on how long it takes to sunburn skin that’s been treated with the sunscreen as compared with skin that hasn’t been treated with sunscreen. Theoretically, the best sunscreen has the highest SPF number. Many dermatologists recommend using a product with an SPF of 30 or more. However, no one really agrees on a “good” SPF number. A sunscreen with an SPF of 60 might be better than one with an SPF of 30, but not necessarily — and the SPF 60 product isn’t likely to be twice as effective as the SPF 30 product. To understand this, remember how sunscreen is typically used. It might not be applied thoroughly or thickly enough, and it might be perspired away or washed off while swimming. All this can make even the best sunscreen less effective than the SPF number on the bottle would lead you to believe.
