According to a report from Spring 2021, if an infected and noninfected person were both wearing cloth masks, it would take around 27 minutes for an infectious dose of COVID-19 to reach the noninfected person. If both are wearing surgical masks, that time rises to about an hour. And if both are wearing even non-fitted N95s, then it would take 25 hours to receive an infectious dose. This was before the Delta or Omicron variants, but should give an idea of their effectiveness levels relative to one another.
How Do I Avoid Counterfeit Masks?
There are a number of ways to spot counterfeit N95 masks, such as by looking for markings on the mask itself or by avoiding N95 masks marketed to children (since the NIOSH doesn’t approve any type of respirators for kids). The CDC offers much more thorough guidance on how to avoid N95 counterfeits on its site.
We don’t recommend buying just any mask you see on Amazon since Amazon allows third-party sellers on its platform that may not vet products as well as those sold by Amazon.com. Walmart, Target, and other retailers may also sell third-party masks. The masks on this list are generally legitimate, as are many masks you’ll find in major retail chains like CVS, or from US manufacturers.
Earlier in the pandemic, the CDC authorized emergency use of KN95, KF94, and other non-N95 masks in health care settings, but that order was revoked in June of 2021. Still, many KN95 or KF94 masks are still more than adequate for everyday use for low-risk individuals, and they’re far better than no mask at all. So, when shopping for a mask, keep in mind what your needs are and how you plan to use the masks you buy.
Can I Reuse Disposable Masks?
If you walk into a gas station for two minutes on your way to work with a brand-new N95 on, do you need to throw it out and use a new one when you get to work? Not exactly.
According to the CDC’s guidelines, N95 masks will lose their effectiveness over a number of hours, but they will also become less effective the more times they’re taken on and off. Part of the reason for this is that the elastic bands wear out and result in a less tight fit. The CDC recommends that if you can’t find data from your mask manufacturer on how many times you can take a mask on and off, don’t remove and replace a mask more than five times. However, this advice is given in the context of hospital settings.