N-COUNT [usu before num]防日光系数 ; sun protection factor的缩写SPF is used before a number to indicate the degree of protection from the sun's rays that is provided by a sunscreen or similar product. The higher a product's SPF, the more protection it provides. SPF is an abbreviation for "sun protection factor." 防日光系数 ; sun protection factor的缩写
First, use a high-quality sunscreen of at least SPF 15 or higher.
第一,要使用防日光系数为15或以上的高质量防晒霜。
However, today there are some products on the market that have SPFs as high as 50.