Have you had issues with "maskne" yet? It's the term people are using for mask-related acne. And if you have to wear a mask all day, there are a few things you can do to prevent it . . .
1. Wash your face more. The main goal is to make sure oil and dirt don't build up. So washing your face is a big one.
2. Wear less make-up. Instead of foundation, try tinted moisturizers that aren't as heavy and won't clog your pores. Or just wear no make-up on the lower half of your face. No one can see it anyway, so what's the point?
3. Wash your mask more often. Or use the disposable kind. You're supposed to wash reusable masks every time you use them anyway. So having at least three or four clean ones that you can rotate in helps.
More on dealing with Maskne here