Of course it's ethical to wear it. If you have some to spare, then it may be ethical also to share with others. We've been donating some of our N95 masks to th

Of course it's ethical to wear it. If you have some to spare, then it may be ethical also to share with others. We've been donating some of our N95 masks to the local hospital, but I'm not donating all of them. My family is important too. As for age, I have noticed that the older ones had crumbly rubber foam and the straps are more delicate, but the melt-blown fabric itself seems perfectly fine. We've re-strapped some with new elastic and replaced the foam with closed-cell foam.