But the increased dependence on the coverings has sparked countless questions. Chief among them: How do I take care of my mask so it continues to be as effective as possible?
We interviewed three medical experts to get their recommendations for what the general public should and should not do when it comes to wearing masks and disinfecting them.
“If you’re reusing a mask over and over again without caring for it in between, that becomes just as dirty as you touching something dirty and then putting it back on your face,” said Jade Flinn, a nurse educator for the Biocontainment Unit at Johns Hopkins Medicine.
What are the general guidelines for proper mask care?
For cloth masks, which have exploded in popularity in recent months, all three experts say daily washings are a must.
“Treat your mask like your underwear,” Flinn said. “You want to change it every day.”
She added: “Thinking about the moisture and the bacteria that’s building up in that mask itself, you don’t want to wear that mask again the next day.”
In a perfect world and not our pandemic-stricken reality that has caused shortages of personal protective equipment, face coverings that are designed to be single-use, such as surgical masks and N95 respirators, should also be swapped out daily after use, said Michael Knight, an assistant professor of medicine at George Washington University.
“You wear a mask all day, particularly in the summer; it’s going to be soiled,” Knight said. “You’re talking, your saliva has been going into the mask, your sweat from your face has been going into the mask.”
Then, there is the added complication that such masks, unlike the cloth variety, cannot be effectively sanitized by a standard washing, said Elizabeth Mullans, a board-certified dermatologist based in Houston.
If I can't wash my surgical or N95 mask, how can I safely reuse it?
Given the limited supply of these single-use masks, it is not uncommon for people, especially health-care workers, to wear the same one more than once.
To prolong the mask’s effectiveness and decrease its chances of being exposed to more contaminants, Knight recommends using a clean paper bag or a plastic baggie for storage.
“But also remember that the outside is contaminated, so you need to wash your hands after touching it,” he said.
What happens if my mask gets sweaty?
Beyond saliva, face coverings, especially cloth and surgical masks, can collect sweat. And a moist mask is a compromised mask, Knight said.
“You want the air to pass through the mask, because you do not have a tight seal around the face like a fitted N95 does,” he said. “If the mask is saturated with fluid, then that fluid is in the fabric of the mask, and air is not going to pass through that.”
Instead, Knight said, air may start flowing through the gaps between the edges of the mask and the wearer’s face.
“That defeats the purpose,” he said. “While yes, it will still catch any contamination coming from your mouth to some extent, it’s just not as effective.”
How do I wash my cloth mask?
The widely recommended method, which has also been promoted by the Centers for Disease Control and Prevention, is simple: Throw the dirty mask in with your regular laundry.
In line with the CDC’s guidance, all three experts said to run your washing machine using warm or hot water. Some washing machine models also have a sanitizing cycle.
Regular laundry detergent is an effective cleansing agent, but Mullans pointed out that certain detergents can leave residue on fabric. This may lead some people to develop skin irritations. For those with sensitive skin who could also be more at risk of developing “maskne,” or acne caused by wearing a mask, Mullans suggested buying a fragrance-free, hypoallergenic detergent. (She uses Arm & Hammer’s Free & Clear for sensitive skin.)
Cloth coverings can also be properly cleaned through hand-washing. The CDC recommends that people use bleach intended for disinfection, mix a solution with cool or room-temperature water and soak the mask for five minutes. The mask should then be rinsed thoroughly with cool or room-temperature water.
Another way to hand-wash calls for warm or hot water and laundry detergent, the experts said.
But Knight said it still may be best to use a washing machine if possible.
“The challenge is there’s no one hard and fast rule,” he said, noting a lack of large-scale studies on the best hand-washing methods for decontaminating masks. “There’s so many different ways to hand-wash. Some people are scrubbing very vigorously, some people are not, some people have stronger hands. If you hand-wash an item five times, you’ll probably wash it five different ways.”
Once your mask is clean, stick it in your dryer on the highest heat setting. “We know that bacteria and viruses, they really don’t like that higher heat,” Flinn said. In the absence of a dryer, masks can be air-dried.
Can sunlight disinfect a mask?
The idea of leaving masks in the sun appeared to gain some steam after lab results promoted by the White House in April suggested that heat and sunlight could have an impact on slowing the virus. The findings were also touted by President Trump. By then, some hospitals had also started using artificial ultraviolet-C light to sanitize N95 respirators.
But natural sunlight may not be an effective way to thoroughly clean a mask, Knight said.
“What I’m seeing is that folks that put it in the sun sometimes are thinking that they are decontaminating the mask,” he said, later adding: “Yes, UV light comes from the sun, but it’s not in a consistent amount to say that, ‘Yes, this has been decontaminated.’ ”
In the case of surgical or N95 masks, sunlight could actually be a bad thing, Flinn said.
“We know that prolonged direct sunlight can degrade some of the plastic materials, even the foam in some of our surgical masks,” she said.
Instructions on a package for a surgical mask sold at a CVS in Potomac, Md., included a similar warning: “Avoid direct exposure of sunlight during storage as the filter media in this mask can be degraded by extended exposure to sunlight.”
What's the best way to store a mask?
Flinn encouraged people to make sure clean masks are stored in places where they cannot potentially be exposed to contaminants, or spread any contaminants already on them.
For example, masks should probably not be hung on the rearview mirror of a car, Flinn said. “If I’m hanging that in my rearview mirror and then I have the air conditioner blasting, is what’s on that mask now blowing around inside my car?” she said.
A similar strategy should be applied to short-term storage, such as when you need to briefly take off your mask while outdoors, Knight said.
“You just have to remember that the outside [of the mask] is likely contaminated,” he said. “You want to remove the mask from the ear loops. You can fold it, keeping the inner parts touching each other.”
Knight stressed that people must remember to wash or sanitize their hands immediately after handling their masks.
“If you covered the outside of your mask with coal, for example, or some fluid that’s easily transferrable and you handled that mask, by the end of the day your hands would be completely covered with it. Because we cannot see the contamination, it’s easy to forget that it’s there.”
How do I know if my single-use mask needs to be thrown out?
Examine it closely, Knight said. If it is visibly soiled or smells, you should no longer be using it.
Flinn said people should also pay attention to the quality of the mask. “One of the things that we see, especially in the surgical masks or the N95 masks, sometimes the ear loops start to degrade, so it’s not creating that good fit,” she said. “You can see the fabric itself starts to fray.” That means it is time to switch to a new mask.