What is SPF? SPF stands for sun protection factor. This rating is used to determine the extent to which sunscreens block UVB rays. SPF 30 blocks 96.7% UVB radiations, and SPF 50 blocks 98%. Let's discuss SPF in more detail. Here are some examples. What are the benefits of SPF? https://www.topscosmetics.uk/product-category/skincare/moisturisers/spf-moisturisers/