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