It seems like the advice about COVID-19 and masks has been all over the map.
When the pandemic first began, we were told masks weren’t necessary. But as scientists gathered evidence of how the SARS-CoV-2 virus was transmitted, that advice was quickly reversed, and many communities began to require that masks be worn indoors to stop the spread.
At that time there was a mask shortage. So to save precious surgical and N95 masks for healthcare workers and first responders, we were advised to make our own masks. But by the time we entered the pandemic’s second year, the shortage had eased, and when the delta wave hit there were enough disposable surgical and N95 masks to go around.
As we’re coming out of the omicron wave, many places are beginning to lift mask mandates, but there are still areas where you may still need to wear a mask — like on public transit and airplanes, as well as in airports.
At this point, health experts are recommending disposable N95 masks or their equivalents, KN95 and KF94 masks. But right now, N95s are averaging about $1.50 per mask on Amazon, while KN95s can be found for about a third of that cost. KF94s are averaging $1 apiece.
It’s no wonder people have been reusing these masks to conserve their supply. But like many of us, I have been wondering how often we can do this before the mask becomes ineffective.
The answer is, it depends….
Length matters more than frequency
According to the U.S. Centers for Disease Control and Prevention (CDC), healthcare workers can wear an N95 up to five times before it needs to be discarded. That’s based on them wearing the mask in a high-risk environment for many hours straight.
For the average person, how long they can wear an N95 or KN95 safely depends on how they’re using the mask. In this case, the amount of time the mask is worn is more important than how often it’s worn.
For instance, using the mask to run to the store is different than wearing it all day at work. You can probably get away with reusing the errand mask a lot more often than the work mask.
As a benchmark, Richard Flagan at the California Institute of Technology recommends limiting the use of an N95 or its equivalent to the equivalent of two or three days. This is because particles accumulate on the mask with every breath you take. And the more particles the mask traps, the less effective the mask becomes.
But this time frame only applies to a mask that’s used under normal circumstances. If you use a mask while exercising, chances are good it will become soiled because you’ll be sweating and breathing hard. If your mask does become wet or dirty, you should throw it away immediately.
Extending the life of your mask
The best way to extend the life of your masks is to let them sit for a few days after each use before you wear them again. The coronavirus can only survive outside the body for 72 hours, so you should wait at least that long before reusing it.
One way to keep track of when you last wore the mask is to put it in a paper bag with the day of the week written on it. Then, wait 5 or 7 days before wearing it again. I also know people who have used a key rack with hooks labeled with the days of the week to hang each mask up.
It’s true that healthcare workers have used dry heat and UV light to disinfect their N95 masks for reuse. But doing this requires a strict protocol that’s difficult for people outside that setting to follow.
Therefore, putting your masks in the sun or under a UV lamp, or in an oven on a low setting, probably won’t be any more effective than simply allowing them to sit in a paper bag for a few days. Worse, using heat or UV light to disinfect your masks could compromise their fit and filtration efficacy.
Source:
How many times can I reuse my N95 mask? — Medical Xpress
Explainer: N95? KF94? Which mask is best at protecting against COVID-19 — Reuters
How to Reuse N95, KN95, and Other Disposable Masks — The New York Times
Types of Masks and Respirators — U.S. Centers for Disease Control and Prevention