Mask Rotation

"This method involves acquiring a set number of N95 masks (the American College of Surgeons recommends up to 7), and rotating their use each day, allowing them to dry for long enough that the virus is no longer viable. According to Dr. Peter Tsai, the inventor of the filtration media contained in the N95, “Polypropylene in N95 masks is hydrophobic, and contains zero moisture. COVID-19 needs a host to survive–it can survive on a metal surface for up to 48 hours, on plastic for 72 hours, and on cardboard for 24 hours. When the respirator is dry in 3-4 days, the virus will not have survived.”"

It means that if you have at home one N95 mask dedicated for going out to buy food, you can do it every 3 - 4 days, dry the mask in between, and reuse it many times safely.  Just do not touch the inside of the mask with contaminated hands if possible.