Mask recommendations are constantly in flux — here's the last mask guide you'll ever need

Now firmly in year three of the Covid-19 pandemic, officials around the country are dropping, then renewing, mask mandates.

That’s a confusing prospect for many. After all, the science has long been clear that this is an airborne virus that can evolve into increasingly transmissible variants. While we’re still learning about the new omicron sub-variants, the heavy uptick in cases suggests the virus is continuing to evolve to be more transmissible. Indeed, on Wednesday, CDC officials said a third of Americans should start masking again in indoor spaces, mostly in the Northeast and Midwest, where cases are rising especially quickly. Because as any aerosol scientist or virologist will tell you: Wearing a respirator like an N95 can be one of the best ways to protect yourself and others from the virus.

It’s a simple truth that’s gotten very complicated. Throughout the pandemic, few mitigation measures have inflamed tensions more than masks and mask mandates. This is, in part, the result of mixed and frequently changing messages about masking communicated by public health officials. The whiplash of going from ‘You don’t need masks,’ to ‘Two masks are better than one’ to ‘Do what you want’ can be exhausting.

Not all masks are created equal, especially when it comes to an airborne virus. The Centers for Disease Control and Prevention (CDC) have repeatedly changed their guidelines on the subject and now with mask mandates being lifted, it’s hard to know the most scientifically sound way to proceed.

Inverse spoke to two bioaerosol scientists about how to wear masks, when, and what kind is best to keep yourself and others safe, regardless of current mask mandates.

What kinds of masks should we be using?

Lisa Brosseau, a bioaerosol scientist and industrial hygienist, has been outspoken about the importance of mask and respirator quality throughout the pandemic. Brosseau notes that most people simply lump all face coverings together and call them “masks.”

“I try really hard to separate the terminology,” she tells Inverse. Masks, Brosseau explains, are cloth face coverings or surgical masks. Respirators — technically called “Filtering Facepiece Respirators” — are specifically designed to protect the wearer when they breathe in. These include N95s and others approved by the National Institute for Occupational Safety and Health.

“People push back on this distinction a lot,” she says. “Sometimes they want to say respirator mask, but there’s no such thing as a respirator mask.”

While it can seem like nitpicking, Brosseau believes it’s a small distinction that can make all the difference.

This is a crucial distinction because a highly transmissible, airborne virus like SARS-CoV-2 means viral particles can linger in the air and get through extremely small gaps in a surgical mask or cloth face covering. Respirators offer the most protection against an airborne virus.

In the absence of mask mandates, when should I wear a mask?

For microbiologist Joshua Santarpia, an associate professor at the University of Nebraska Medical Center, the elimination of mask mandates isn’t changing his behavior much. Santarpia is a bioaerosols expert. In fact, he was among the first researchers to offer evidence that SARS-CoV-2 could be airborne.

“For me, masking really doesn't change very much regardless of what the mandates are,” he tells Inverse. If he’s going to be in a space that’s indoors and with people outside his household, he performs his own risk assessment. His three primary considerations are:

• How crowded is the space? (Will you be waiting in a long line? Can you move around without bumping into someone?)
• How long will you be there? (15 minutes or less would be considered a quick trip)
• What are the current community transmission rates in your area? (You can check the community transmission rates for your county via the CDC’s Covid-19 County check. Mask mandates have traditionally been imposed when community transmission is at 5 percent or above.)

“If transmission rates are low and I’m going into an uncrowded place, I might not feel the need to wear a mask because my likelihood of exposure [to the virus] is low,” he says. “But if I’m going to a crowded place — regardless of transmission rates — I’m going to wear a mask, simply because I am not interested in getting sick. Or taking the chance.”

As a hospital worker, Santarpia has access to N95 respirators and that’s what he wears in grocery stores and other crowded, indoor places as well as when he’s at the hospital.

“When there’s no mandate, I see it as an opportunity to make an informed decision. That doesn’t mean I throw all my masks in the garbage. It just means I perform my own risk assessment,” he says.

For example, even though surgical masks don’t provide nearly as much protection as an N95, if community transmission is low and you need to quickly run into an uncrowded grocery store, a surgical mask may work just fine, Santarpia says.

“If people get used to wearing masks, it’s only a bad thing for diseases”

Still, there are many reasons it may make sense to err on the side of caution when making that risk assessment.

“If people get used to wearing masks, it’s only a bad thing for diseases,” Santarpia says. “They work even better against the flu than they do this. If, during flu season, you don’t like getting the flu, wearing a mask makes sense.”

There are also certain populations where wearing a mask remains crucial. People who are immunocompromised may still need the added protection, as do many parents and families with kids under 5 who don’t yet qualify for the vaccine. Further, researchers still don’t fully understand how or why long Covid occurs, or who is most at risk or susceptible.

Santarpia contracted Covid-19 in the pre-vaccine era. He was largely asymptomatic, he says, but lost his sense of taste and smell, which have only partially recovered. He says he’s going to do whatever he can to avoid contracting it again because “I don’t really have a desire to even chance getting it again.”

Can I reuse my N95 or equivalent?

While supplies of N95s and other face filtering respirators are more available now than they were at the beginning of the pandemic, they can still be pretty pricey. Plus, disposing of a mask after every grocery store run can get wasteful pretty quickly.

Reusing an N95 endlessly will eventually decrease its efficacy (and it’s less hygienic), but most people can get away with reusing it a couple of times, Santarpia says.

“I think for the average person, resuing an N95 is fine,” he says. “If you’re wearing it while you run a few errands, I think it’s fine to use it three or four more times; you can really extend the life of an N95 that way. But if you’re going to be wearing it all day, or around Covid-19 patients, you’re going to want to change it after each use.”

If you want to decontaminate your mask after each use, put it in a brown paper bag and store it in a cool, dry place.

If I just had Covid-19, do I still need to wear a mask?

If you had Covid-19 and are no longer testing positive, there’s a fairly low risk of immediately contracting it again. And if you don’t have it, you can’t spread it. That said, everyone is different and Omicron is better able to evade immunity than other variants, so there’s no definitively safe window for all people. Further, that in-between period will end eventually, even if there’s no guaranteed set of time. Typically, you are least likely to be reinfected with Covid-19 within 90 days of clearing your previous infection.

What if no one else is wearing a mask?

At the risk of sounding like the mom of a teenager sitting them down for a peer pressure talk: Just because everyone else is doing something doesn’t mean you have to as well. Everyone’s circumstances are different. Maybe you’re the only person with an immunocompromised family member at home. Maybe you’re not as worried about getting Covid-19 but you really don’t want to develop long Covid. Make a decision based on what you feel comfortable with, not what everyone else is doing.

Dropping mask mandates may be more about political science than medical science, but the good news is that any shifts in the public legislature don’t have to change your own behavior. Medical science can still inform your decisions and what you’re comfortable with.