“I wear mine for a week,” said Linsey Marr, a civil and environmental engineering professor at Virginia Tech.
The material and filtration ability of an N95 mask “won’t degrade unless you physically rub it or poke holes in it,” Marr said. “You would have to be in really polluted air… for several days before it loses its ability to filter particles. So you can really wear them for a long time.
“People have talked about 40 hours – I think that’s fine. Really, it’s going to get gross off your face or the straps are going to get too loose or maybe break before you lose your filtration ability,” she added.
The reason N95 masks are designated as single-use is that they are categorized as medical masks, said Erin Bromage, associate professor of biology at the University of Massachusetts at Dartmouth.
In medical settings, healthcare workers are changing masks more frequently to avoid “contaminating a patient room with equipment that has been worn in an infectious person’s room, then moving to the next room and bring this infection with you,” he said. “When you then take a single-use, medical-grade item and put it out to the general public, we’re not concerned about you contaminating different environments that you’re in. It’s really about providing you with protection.”
The N95s “only cost about $1 each,” Bromage added, but prices have skyrocketed recently as public demand for these masks has grown amid concerns about Omicron variants. If you safely reuse N95s, you get at least two or three days of mask use, Bromage added, but “I realize that’s still an expense.”
Here’s what else you need to know about safely wearing and reusing N95 masks.
N95 masks “are not made for children,” Marr said. “For bigger kids, my 10 year old wears a small size N95 (intended for adults).”
“If you see an N95 as being marketed for kids, that should raise a red flag,” Marr added. “There will be KN95s and KF94s that are designed and marketed for children. With these it’s the same issue that we discussed for adults, which is making sure you get them from a reliable and reputable source, because there is a problem with fake KN95s not being as protective as they should be.”
The KF94 are Korean standard masks.
Reusing an N95 mask – and when not to
To reuse N95 masks in the safest way possible, avoid touching the front outer portion of the mask when putting it on, Marr said. Instead, try handling it by the edges or the straps. “Absolutely avoid the part right in front of where you breathe, like right in front of your nose and mouth,” she added.
Even after wearing an N95 in a crowded indoor environment – like a subway – Marr said “these masks are really designed to handle a lot of particles and will continue to work.”
However, a known exposure should affect your approach. If “I was working in an office and I was wearing an N95 and someone in my office had tested positive, I would know I was well protected,” Bromage said. “But I would probably throw that mask away. Because that mask did its job of trapping the virus and I don’t even want to risk it being there and falling on my hands or whatever.”
If the mask becomes damp, visibly dirty, bent, creased or otherwise damaged — including from makeup — you should replace it because these conditions could decrease the effectiveness of the mask, Marr and Bromage said.
“The longer you wear it, the more it actually holds the material, which means the breathability, the resistance of the mask, starts to decrease,” Bromage said. “One of the first indicators of being able to change it if it looks nice and clean is that it just seems a little harder to breathe in. There seems to be more resistance with each breath.”
How to Disinfect N95 Masks
The longer and more frequently you wear an N95 mask, the more contaminated it can become. But the particles will die over the course of a few to several hours, Marr said, and even faster if you set the mask aside in the sun.
“Things like temperature and sunlight have an effect, but you don’t want to throw them in an oven or microwave,” Bromage said. “I used to stick mine on my car dash in the summer, and that would do more than enough as far as the heat and direct light it got. But in reality, it doesn’t There’s nothing you can really do to prolong its lifespan with cleaning that the average person can afford.”
Because N95 masks have this special static charge that helps filter out viruses, you shouldn’t wash the masks because the water will dissipate the charge, Marr said.
Overall, the risk of contamination from reusing N95 masks is “lower, much lower, than the risk of you not wearing N95 and breathing in particles,” Marr said. “I don’t want people to avoid wearing an N95 because they’re worried about contamination on an N95. The N95 is going to provide a major net benefit.”