According to theSkin Cancer Foundation, you should reapply sunscreen every two hours for effective protection.
If you’re scratching your head about how to reapply your SPF over foundation, don’t despair.
That’s where powder sunscreen comes in.
They should be reserved as a mess-free touch-up for added protection (viaHuffPost).
That means you should use the powder only to complement your initial system of daily sunscreen.
UVA is emitted at the same level all day long."
