It's made of cotton fabric.
It has four (4) layers
1st layer is cotton fabric
2nd layer is foam as filter
3rd layer is nylon fabric as lining
4th layer is cotton fabric which is the one will touch your face.
It is made of cotton so it will be gentle to your skin. It is washable and reusable.
Note: Please use this mask one time only then wash it properly and iron it before using it again to ensure bad elements are dead and gone.
Be safe and hope everything will be fine.