Before answering that question, I'll start with something really important.    How to use a N95 mask more than once.     I largely provided this information last week, but it doesn't hurt to repeat by indicating my variation to a  Wirecutter   article. Get seven small paper bags, each big enough to hold a N95 mask.   Write a different day of the week on the bags:  Sunday, Monday, etc. Place a N95 mask in each. Wear the mask of that day, and after doing so, place it back into that bag. This virus is supposed to die after three days of exposure. They say four days should be sufficient, so five is safer.  Seven might be more convenient for there are seven days in the week.  A typical box of N95 NIOSH masks holds 20. A few other points: Moisture, especially from vigorous use working out in a gym could wet your mask.  This is why you use a paper bag because it breathes, unlike a ziplock bag. Place the paper bag near a dry sunny window.  But  keep the sun from striking the bag . If y