FAQ: Single or double? The latest advice on masks and covid.

January 26, 2021

This story has been updated.

At this stage in the pandemic, amid a surge in infections and the emergence of new, more transmissible variants of the novel coronavirus, masks aren’t just a fact of life. They’re a critical tool in slowing the spread of the virus until enough of the population can be vaccinated.

Below we’ve compiled answers to some of the most commonly asked questions surrounding masks and how to navigate pandemic life in them. These recommendations are drawn from previously published Washington Post articles and new interviews with medical professionals and public health experts who have been on the front lines of this pandemic.

[Covid-19 etiquette: A comprehensive guide]

Please keep in mind that as the coronavirus continues to be studied and understood, masking advice may change, and we will update this FAQ accordingly.

How to wear a mask

How do I properly wear a face covering?

Fit is key, experts say. For a mask to do its job, it should fit closely to your face, shielding your nose and mouth completely. A number of widely available cloth masks now feature adjustable nose wires and ear loops to help you achieve a better fit.

“If the mask is not fitted well and there are large gaps around your nose or to the side of your cheeks or under your chin, then you’ve defeated the purpose,” says Gregory Poland, director of the Mayo Clinic’s Vaccine Research Group.

[When, why and how to wear a mask during this pandemic, according to the experts]

Should I be double-masking?

In recent months, a growing number of public figures including football coaches and politicians have been spotted wearing two masks — usually a cloth covering over a medical-grade mask. “If you have a physical covering with one layer, you put another layer on, it just makes common sense that it likely would be more effective,” said Anthony S. Fauci, the nation’s top infectious-disease expert, during a January appearance on the “Today” show.

Not everyone, however, needs to start wearing two masks all the time, says Monica Gandhi, a professor of medicine and an infectious-disease expert at the University of California at San Francisco. Gandhi, who recently co-authored a commentary on the science behind mask-wearing, suggests doubling up on face coverings if you are spending time indoors in crowded spaces or in areas where transmission rates are high. People who are medically vulnerable should also consider layering their masks, she says.

“We do actually have to tailor our recommendations,” Gandhi says. Otherwise, “it will just cut down on acceptability.”

The Centers for Disease Control and Prevention has not updated its mask guidance to recommend layering masks.

How do I effectively layer masks?

The purpose of wearing two masks is to improve fit and filtration, Gandhi says. And if the masks are layered properly, they can closely simulate the effectiveness of an N95 respirator, which many experts consider to be the gold standard. In the January commentary, Gandhi and co-author Linsey Marr, a Virginia Tech professor who studies airborne transmission of infectious diseases, recommended two ways people can layer their masks for “maximal protection.”

Option 1: Wear a tightly fitted, multiple-layer cloth covering over a surgical mask. “The non-woven polypropylene material of the surgical mask is electrostatically repulsing the virus and then the cloth mask literally forms a physical barrier with fibers going every which way,” Gandhi says.

This method can also use KN95 or FFP2 masks as the base layer, but Gandhi says she does not recommend putting a cloth mask over an N95. “An N95 is as good as it gets,” she says, adding that the respirators are typically fitted to a person’s face, providing a tight seal.

Option 2: Wear a three-layer mask with tightly woven fabric outer layers sandwiching a middle layer made out of a “nonwoven high-efficiency filter material,” such as a vacuum bag filter, the article states. The filter material will act similarly to a surgical mask or other medical-grade covering, Gandhi says.

Double-masking shouldn’t be “misconstrued to say more and more layers of cloth,” Gandhi notes. Additional material that doesn’t function like a medical-grade mask “is of no utility and will just make your voice muffled,” which may then cause you to pull your face covering down to speak.

Can I leave my nose exposed?

No. “People who wear the masks underneath their nose really are doing very little good for anybody,” says Mark Rupp, chief of the infectious diseases division at the University of Nebraska Medical Center.

The nose is also one of the prime entry points for the novel coronavirus, says Poland. He notes that a key protein, called the ACE2 receptor, which the coronavirus uses to enter and infect cells, is found in higher densities in the nasal membrane than the trachea, or windpipe.

“Wearing a mask over your mouth but not your nose is akin to holding the seat belt in your hand but not clicking it,” he says.

Will covering my nose and mouth affect my ability to breathe?

Although it may feel like it’s harder to breathe when wearing a face covering on a regular basis, common surgical and cloth masks have “zero impact” on oxygenation and quality of breathing, Gandhi says.

Oxygen and carbon dioxide molecules are “so tiny … they absolutely can happily and freely go through” a mask, she says.

Medical professionals often spend long hours each day in masks and are able to do their jobs “quite well,” Poland says. Neysa Ernst, nurse manager of the Biocontainment Unit at Johns Hopkins Medicine, adds that even in the pre-pandemic days, many respiratory-compromised people wore masks largely without issue.

“For years, we’ve taken care of lung transplant patients and cystic fibrosis patients who are some of the most respiratory-compromised patients you can ever imagine,” Ernst says. “They would never come to the hospital or move around the hospital without a mask. … So if that population, who really would have a valid statement of saying, ‘It’s really difficult for me to breathe,’ if they’re able to do it, I think the rest of us can.”

Are there legitimate exemptions to mask-wearing?

“Very few,” Rupp says. According to the CDC, face coverings should not be worn by children under the age of 2; people who have trouble breathing; or anyone who is unconscious, incapacitated or otherwise unable to remove a mask without assistance.

“You could foresee circumstances where the mask could get into somebody’s mouth or throat and cause choking,” Rupp says. “If they really don’t have the ability to reach up and pull the mask away, they probably would not qualify for wearing a mask.”

The CDC offers recommendations for people who have mental disabilities or sensory sensitivities on its website. It also recommends that anyone who regularly interacts with people who are deaf or hearing-impaired consider using masks with a clear window in the front. For others with disabilities that make mask-wearing difficult, such as those with autism, it suggests talking to your health-care provider. Some doctors have written exemption notes in such cases. But there’s no guarantee a note will be accepted, as one mother of an autistic 3-year-old found when her family was removed from a Southwest flight in August.

[When a deaf man couldn’t read others’ lips, he created a better mask]

How do I get my child to wear a mask?

In addition to following proper fit guidelines, Ernst says children’s masks have to be comfortable.

“If it’s uncomfortable, they’re going to take it off the minute that you walk out the door or they’re going to push it down below their chins,” she says.

Gandhi suggests using adjustable face coverings, which can give children “some sense of control.” She also recommends looking for masks with playful designs such as rainbows or superheroes, or matching a child’s face covering to their outfits.

“Make it fun,” she says.

But getting children to adjust to mask-wearing involves more than just picking the right covering, experts told Jennifer Davis in a recent Post story. It takes planning and patience.

[How to help children adjust to masks, according to experts and parents]

This might involve teaching children, especially younger ones, how to read emotions while wearing a mask, Rebecca Schrag Hershberg, a clinical psychologist, parenting coach and author, told Davis. Children should also be shown good mask-care habits, such as how to put their mask on a clean paper towel or in a clean paper bag or plastic container when they have to take it off, Davis reported.

Throughout the period of adjustment, Hershberg and other experts said parents or guardians should be patient, provide positive reinforcement and validate how their children may be feeling.

“It’s not helpful to say things like, ‘It’s not that bad,’ or ‘Come on, what’s the big deal?’” Hershberg said. “It’s far better to acknowledge that this is different and does feel weird, but that it’s also important and something we need to do for the health of our community.”

How do I safely adjust or remove my mask?

You should try to avoid touching your mask as much as possible, Ernst says. When you do need to handle it, she says it’s best to only touch the ear loops or, if necessary, the portion of material that sits under your chin.

“There’s a lot of contaminants in the air, so that’s going to be on the front of your mask,” she says. “And then you’re going to be putting your hand on that and then touching your face.”

Ernst recommends thoroughly sanitizing or washing your hands before and after touching a contaminated mask. In our mask care FAQ, Michael Knight, an assistant professor of medicine at George Washington University, also emphasized the importance of hand hygiene.

“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,” Knight said. “Because we cannot see the contamination, it’s easy to forget that it’s there.”

What do I do with my mask if I need to sneeze?

“When you cough or sneeze, these particles can travel much further than they usually would by talking at a normal volume or just exhaling in a normal way,” Maria Sundaram, a postdoctoral fellow and principal investigator on covid-19 epidemiological research at ICES Ontario, told The Post’s Eliza Goren.

[How to sneeze during a pandemic]

In the event of a sneeze, a mask could serve as an effective barrier to keep potentially infectious droplets from spraying into the air, Goren reported. But sneezing into a mask can make it wet and cause it to be less effective, Eleanor Murray, assistant professor of epidemiology at Boston University School of Public Health, told Goren. Murray said she recommends always carrying a fresh “backup mask.”

What happens if my mask gets wet?

Whether it’s saliva, sweat or any other form of moisture, a wet face covering is not ideal, according to experts.

“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,” Knight told The Post in August. “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.”

When single-use surgical masks get wet they “fall apart,” Ernst says. She adds that even sturdier N95 masks can also start to degrade if exposed to too much moisture. That’s why health-care workers who wear them on a daily basis often store them in paper bags.

“The paper bag will then absorb some of the moisture that naturally occurs in the mask and so then you can reuse the mask,” Ernst says.

Why do my eyes feel dry? Why do my glasses fog up?

These are related issues that are probably due to your mask not fitting tightly to your face, allowing exhaled air to escape from the top, eye experts told The Post for an article explaining the phenomenon of “mask-associated dry eye.” But they aren’t reasons to stop wearing a mask, said Lyndon Jones, director of the University of Waterloo’s Centre for Ocular Research and Education in Canada.

One of the simplest fixes for both problems is to make sure your mask is properly fitted. Many face coverings can be modified to fit more snugly by simply adjusting the nose wire or ear loops. Additionally, some experts have suggested using medical tape or an adhesive bandage to close the gap.

[You’re not imagining it. Masks can make your eyes feel dry. Here’s what to do.]

For glasses wearers, it may also be helpful to rinse your glasses with a bit of soap and water or apply other appropriate anti-fogging solutions before putting on a mask.

What do I do if my mask gives me acne?

Skin irritation and breakouts caused by mask-wearing have become so common during the pandemic that the term “maskne” was recently added to Urban Dictionary, Danielle Braff reported.

“Virtually all skin types will see some form of irritation from wearing a face mask if they are wearing them for extended amounts of time each day,” Dendy Engelman, a dermatologic surgeon in New York, told Braff. “Many people will see irritation from the physical friction and/or pressure of the material on their skin, while others will see acne pop up.”

[Wearing a mask can irritate your face or make it break out. Here’s what to do about ‘maskne.’]

If you are experiencing “maskne,” look for a gentle cleanser and products designed to hydrate, repair and support the skin’s barrier function, Engelman said. Skin irritation caused by friction can be alleviated with moisturizing ointments, and cleansers containing salicylic acid, benzoyl peroxide or elemental sulfur are recommended for treating breakouts, Braff reported. It is best to avoid wearing makeup, which can soil your mask and clog your pores.

Skin experts also recommended paying attention to the type of mask you’re wearing and making sure to keep it clean. Adam Mamelak, an Austin-based dermatologist, said the best cloth mask for skin is one with multiple layers of silk or silk lining. Silk has antimicrobial properties and has been shown to be better for people with sensitive skin, Braff reported.

Types of masks

What kinds of masks are recommended for the general public?

N95 masks are widely considered by experts to be the most effective mask available. But public health agencies have recommended that the coveted N95s largely remain reserved for those who work in health care, among others in more at-risk populations.

[The N95 shortage America can’t seem to fix]

For the general public, experts say surgical masks and multiple-layer cloth coverings made of tightly woven material are effective forms of protection. In a guidance on masks, the CDC recommends face coverings made of two or more layers of breathable, washable fabric, such as cotton. Experts with the World Health Organization say three-layer fabric masks are ideal.

But amid a recent surge of winter cases and the emergence of new, more contagious, strains of the coronavirus in Europe, a growing number of nations there have started to recommend or require the use of medical-grade masks. In Germany, for instance, people riding on public transport or in grocery stores have to wear N95s, equivalent coverings such as KN95s or FFP2s, or surgical masks.

The changes rolling out across Europe appear to conflict with guidance from the WHO, which still states that medical masks should be restricted to health-care workers, people showing covid symptoms, those coming into contact with an infected person and those who may be vulnerable to developing more severe illness.

[Europe’s growing mask ask: Ditch the cloth ones for medical-grade coverings]

Can I use a mask with an exhalation valve?

Masks with valves or vents are “not proper masks” and should be considered “minimally helpful,” Poland says. In August, the CDC updated its guidance to recommend against using such masks, which were originally created for “hot and dusty construction work,” The Post’s Reis Thebault and Angela Fritz reported.

According to the CDC, “masks with one-way valves or vents allow air to be exhaled through a hole in the material, which can result in expelled respiratory droplets that can reach others. This type of mask does not prevent the person wearing the mask from transmitting COVID-19 to others.”

[Face masks with valves or vents do not prevent spread of the coronavirus, CDC says]

Should I use a neck gaiter?

Neck gaiters have emerged as one of the most widely debated types of face covering amid the pandemic. Gaiters gained popularity as a more comfortable alternative to traditional masks given that they are often made of lightweight, breathable material and don’t require ear loops.

In August, Duke University researchers unveiled a simple device to evaluate the effectiveness of various coverings, and a single-layer polyester gaiter performed poorly in that test, ranking slightly lower than the study’s no-mask control group.

“These neck gaiters are extremely common in a lot of places because they’re very convenient to wear,” Warren S. Warren, one of the Duke researchers, told The Post at the time. “But the exact reason why they’re so convenient, which is that they don’t restrict air, is the reason why they’re not doing much of a job helping people.”

But subsequent research conducted by aerosol experts has suggested that when a single-layer gaiter is worn doubled up, it is highly effective at blocking a range of particle sizes. In experiments done by Marr, the Virginia Tech professor, a doubled-up gaiter blocked more than 90 percent of the particle sizes tested.

Researchers at the University of Georgia also recently studied gaiters and tested the coverings using an enhanced version of the method developed by the Duke scientists. They found that gaiters with multiple layers performed better than standard two-layer cloth masks tested, providing a 96 percent average reduction in respiratory droplets compared with wearing no covering at all.

[‘A lot of variables’: New research into popular gaiters highlights challenges of testing mask safety]

Although the CDC previously tagged gaiters with a “caution” label, in late October the agency updated its guidance to say that if you choose to wear the face covering, it should have two layers or be worn doubled up. Still, the CDC notes that “evaluation of mask and gaiter materials and structure is ongoing.”

Can I wear a plastic face shield instead?

“I see a lot of people with face shields and no mask,” Ernst says. “No, it’s not one or the other.”

The CDC states that face shields are “primarily used for eye protection for the person wearing it.” While Gandhi says there hasn’t been “clear documentation of ocular transmission” so far, a recent study published in JAMA Ophthalmology suggested that wearing glasses could offer some protection. But the scientists emphasized that their study had “notable limitations” and called for further research.

It is not also yet known “what level of protection a face shield provides to people nearby from the spray of respiratory droplets from the wearer,” the CDC says, adding that it does not recommend the plastic barrier as a substitute for masks.

If you only wear a face shield, you are allowing unfiltered air to flow in and escape from the large gaps between the edges of the shield and your face, Gandhi says. Face shields, she notes, should be worn in addition to a mask in the event that another layer of protection is needed or wanted.

“I actually do not recommend people run around with both,” she says. “I’m very comfortable with the powerful effect of the facial mask. But if you are doing a close procedure or if you are very high-risk and really just want to minimize any questions, you can wear face shield.”

How do I know if my mask is effective?

There are simple tests you can do to evaluate a face covering, Poland and Ernst say.

Poland recommends holding up a mask to the sun or another light source. If you can see through the material, “it’s not a mask,” he says. Meanwhile, Ernst suggests putting on your mask and trying to blow out a birthday candle.

“You should not be able to blow out a birthday candle with a mask on,” she says.

When to wear a mask

If I contracted the coronavirus and recovered, do I still need to wear a mask?

Yes, experts say — at least until there is a greater understanding about the virus and people’s immune response to it.

“Number one, you might potentially still be able to spread it,” Poland says. “More importantly, you don’t know when you will become susceptible again.”

There have been at least two documented cases of reinfection. In August, researchers in Hong Kong released a preprint study purporting to be the “world’s first documentation” of a patient who recovered from covid-19 becoming reinfected. That same month, a 25-year-old Reno man became the first reported reinfected coronavirus patient in the United States.

[First coronavirus reinfection documented in Hong Kong, researchers say]

For now, Rupp says, “it would be better to play it safe.”

“Until we know more about how durable people’s immune response is and whether they’ve had an immune response, it would be in their best interest to continue to practice distancing and to continue to wear a mask,” he says.

Do I have to wear a mask after I get vaccinated?

Yes, experts say — at least for now.

The covid vaccines being distributed to the public are not “an antidote to it all,” Namandje Bumpus, director of the Department of Pharmacology and Molecular Sciences at Johns Hopkins University, told The Post. “Certainly, all of us getting vaccinated moves us toward that more quickly, but it’s not something that we’re going to be able to do as soon as we get vaccinated. We’re going to have to continue to be diligent the way that we have been.”

[Yes, people with coronavirus vaccinations should still distance from each other. Here’s why.]

Although the Pfizer-BioNTech and Moderna two-dose vaccine regimens are both highly effective at preventing illness from the virus, they don’t provide instant and complete protection. It typically takes a week after the second dose for the Pfizer-BioNTech vaccine to reach 95 percent efficacy. Moderna’s vaccine efficacy increases to 94 percent two weeks after the second shot.

“On a population level, 95% efficacy still translates to 5/100, or 50/1,000, or 500/10,000 vaccinated persons still being vulnerable to symptomatic disease and maybe even more having asymptomatic carriage,” Onyema Ogbuagu, the principal investigator for Pfizer’s vaccine trial at Yale University, wrote in an email to The Post.

There are also still unanswered questions about whether vaccinated people can transmit the virus, which experts say is a major concern as the country grapples with high rates of community transmission and a slow vaccine rollout.

“In the short term, life is going to look much the same until much more of society has had a chance to be vaccinated,” Robert Atmar, a professor of medicine in the Section of Infectious Diseases at Baylor College of Medicine in Houston, told The Post.

Do I have to wear my mask even when I’m social distancing?

It is believed that the novel coronavirus primarily spreads through person-to-person contact within six feet, leading public health experts to widely recommend that people at least maintain that distance between themselves and others. But emerging research suggests that it may be possible for virus droplets to travel farther than six feet, especially in poorly ventilated areas, The Post’s Ben Guarino reported in August. The CDC has since updated its guidance on how the virus spreads to include airborne transmission as a possibility.

[No matter what the CDC says, here’s why many scientists think the coronavirus is airborne]

So for now, “the recommendation is to do both,” Gandhi says, adding that clearer information “on whether one is more important than the other” will come with time.

Ernst notes, “It’s not a mask or six feet away. It’s a mask and six feet away.”

For outdoor, socially distant gatherings, though, Rupp says masking is “probably not necessary.”

“But if you’re in close confines, even if you’re outdoors and you’re in a crowd, then you absolutely should be wearing a mask and so should everybody around you,” he says.

Should I wear a mask if I’m exercising outdoors?

Masking is mandated by a number of indoor gyms and fitness studios, but experts say the guidelines around exercising outdoors are a bit more flexible.

“If you’re not around anyone and you’re, like, running, it really is okay not to wear it,” Gandhi says. She recommends keeping a mask handy in case you do end up coming into close contact with other people.

In the absence of a mask, you should be mindful to keep your distance, Virginia Tech’s Marr, told The Post’s Teddy Amenabar. Marr encouraged people exercising outdoors to try to keep at least 10 feet away from others.

“Six feet isn’t some magic boundary beyond which there’s zero risk,” Marr said. “The farther you are away, the better.”

[So, you’re getting into running during a pandemic. Here’s what you need to know.]

How to care for a mask

How do I disinfect a single-use mask?

In health-care facilities, N95s have been cleaned for reuse using vaporized hydrogen peroxide and advanced UV treatments, experts say. Those methods aren’t easily available to the public, but researchers from the University of Illinois at Urbana-Champaign recently found that the dry heat produced by household electric cookers (rice cookers or multicookers such as Instant Pots) may be an effective way of disinfecting N95s.

[Researchers found a way to clean N95 masks for reuse — in a common electric cooker]

A simpler way might be exposing N95 or surgical masks to sunlight for short periods of time, Rupp says, noting, “The virus is relatively wimpy, if you will, and so it’s not an environmentally hardy virus.”

But too much sun exposure could potentially be harmful, Jade Flinn, a nurse educator for the Johns Hopkins Biocontainment Unit, told The Post in August.

“We know that prolonged direct sunlight can degrade some of the plastic materials, even the foam in some of our surgical masks,” Flinn said.

When it comes to surgical masks, Gandhi says she and her colleagues “really just use them and throw them away.”

How many times can I use a surgical mask before it needs to be thrown out?

“No one knows,” Poland says. “Nobody’s done a piece of research that would give us a black-and-white answer.”

Instead, Rupp says it depends on how often and how long you’re wearing your non-washable mask.

“If they’re being worn for a brief period of time while you run out to the store and then set it aside when you’re back in the car, you could probably do that multiple times without any difficulty,” Rupp says. “If you’re wearing it for a prolonged period of time, it becomes damp, soiled, torn, then it’s going to be time to dispose of it.”

Can I clean my masks with rubbing alcohol or other disinfectant sprays?

It’s generally not recommended.

Cloth masks can be easily cleaned in the laundry or hand-washed with soap and water, according to experts and the CDC. Once masks are washed, they should be thrown in the dryer on the highest heat setting or air-dried.

Although it’s much harder to disinfect N95s and surgical masks, which are designed for single use and can’t be laundered, Ernst says wetting them with sprays will only cause them to degrade faster.

“I have a surgical mask right in front of me, and if I were to spray that with some disinfectant, it would disintegrate,” she says.

[FAQ: How to care for your face mask (and why you shouldn’t hang it from your rear-view mirror)]