In-Depth: How long can an N95 mask be reused?

Experts discuss when to throw away N95 masks
Posted at 6:10 AM, Feb 02, 2022
and last updated 2022-02-02 10:32:24-05

SAN DIEGO (KGTV) - Pharmacies and clinics have begun giving out N95 masks to people as part of the federal government's COVID safety program. People can get three free masks at any number of locations.

But experts say those will only last for so long, and people need to be vigilant to make sure they get the most from each mask.

"As long as it's staying reasonably clean and unsoiled, they can be reused," says Dr. Jim Schultz, the Chief Medical Officer at Neighborhood Healthcare in Escondido.

RELATED: Free N95 masks begin arriving in San Diego

His clinic is one of three in San Diego County that got a supply of masks from the Health Resources and Services Administration's COVID-19 N95 Mask Program.

Dr. Schultz says a good rule of thumb is that each mask will last 3-5 days as long as it's well taken care of and you keep an eye out for wear and tear.

"The things that we look for is if it gets soiled," he says. "Some of the bands that go around your head can get stretched out. Sometimes they get detached. Also, if it just stops fitting your face very well, it's time to replace it."

Dr. Francesca Torriani from UC San Diego says you should check the seal to ensure no air can get in or out when you breathe.

She also says to make sure you keep the mask dry.

"If it becomes humid or wet, the filtration will not be effective," says Dr. Torriani.

"Part of the way these masks work is there's an electrostatic charge that traps the smaller virus particles in the smaller droplets," explains Dr. Schultz. "So if the mask got soaked, that electrostatic charge goes away."

Mask longevity also depends on where and for how long people wear their N95. Doctors say you should replace it if you wear the mask for an extended period in a hospital or healthcare setting or a crowded, indoor place.

But if you're only using it for quick errands or outdoor activities, it can be reused, as long as you don't take it on and off repeatedly.

"The more you use it, the more you're going to have touched it with your hands," explains Dr. Torriani. "(Your hands) will have bacteria, and you could have picked up viruses or other things."

That's also why they recommend washing your hands before and after touching your mask. You should also keep the masks in a clean space in between uses.

Dr. Schultz says he puts his N95 masks in paper bags on his desk. He numbers the bags and rotates between the masks to avoid overusing each one.

He says a set of three masks could last up to two weeks if they're properly cared for.

"Then, hopefully, we'll be resupplied (with more)," Dr. Shultz says.

For a list of places giving out masks, click here.