Here are the results of our investigation into Do N95 Masks Protect Others? Here's What We Know. Free N95 masks where can i get free N95 mask near me how do you test the quality of a KN95 mask? With Valve N95 respirator with valve n95 masks are constructed to withstand up to forty hours of use. When possible, it's ideal to stay clear of being close to others who are not putting on masks. As soon as it shows signs of wear and tear, you should get a new one. There are still plenty of options to do so-you just need to know where to look!