What You Need To Know About Double Masking

As new, more contagious COVID-19 variants spread, people are wondering whether double masking can help lower our risk of exposure. Layering two masks is something U.S. President Joe Biden and First Lady Jill Biden have been doing for months, and this week, U.S. White House advisor Dr. Anthony Fauci said that wearing two masks is likely better than one. At President Joe Biden’s inauguration, some attendees were seen double masking, such as youth poet laureate Amanda Gorman and former presidential candidate Pete Buttigieg, who both wore disposable paper masks underneath cloth masks—the same approach Dr. Fauci has been employing.

In Canada, mask recommendations have remained the same since November, when the Public Health Agency of Canada (PHAC) recommended the use of three-layer masks. PHAC recently said they don’t currently have plans to release new mask guidelines. But with two masks likely offering more protection than one, is there a case to be made for double masking? We asked two experts.

Has double masking been proven to be more effective?

A small study found that mask protection and filtration is improved when wearing two masks as opposed to one if a higher-functioning mask—such as one with three layers—isn’t available. However, this is not conclusive evidence, because the study hasn't yet been peer-reviewed and can’t be used to guide doctors and clinicians.

Dr. Gerald Evans, professor and chair of the Division of Infectious Diseases at Queen's University in Kingston, Ont., says though we have no significant data that double masking is more efficient in preventing transmission, it makes sense that it likely would be. The idea of double masking is based on the theory that the bigger the barrier you create with a mask, the safer you are from transmission, he says. “It would make some sort of common sense that two masks, whether they be fabric or whether they be a mixture of medical and fabric, would be useful.”

Why are people talking about double masking now?

Natasha Salt, director of infection prevention and control at Sunnybrook Health Sciences Centre in Toronto, says the growing dialogue surrounding double masking is likely due to the fact that there’s so much inconsistency among the types of masks available to the public. As well, the arrival of the new variants has brought us to a “fork in the road,” she says, as public health officials try to understand the mechanisms of transmission. (Both the U.K. and South African variants are thought to be more transmissible than the original COVID strain.)

What materials should be used for double masking?

When doubling up on your masks, Evans recommends the outermost mask should be made from a material that is water resistant. He says the inner mask should be a material that has a good filtration capacity; for example, a Level 1 disposable medical mask or a closely woven cotton mask with an interlaying layer of polypropylene—a synthetic material that traps particles. This echoes PHAC’s current three-layer mask guidelines, which recommend that a mask has two layers made of tightly woven material fabric, such as cotton or linen, and a third (middle) layer made of a filter-type fabric. Evans says having an extra filter helps in absorbing moisture and retaining the mask’s filtration capacity.

In some European countries like France and Germany, governments are recommending that when in public, people wear surgical masks or medical-grade respirators, such as KN95 or FFP2 (both respirators that work similarly to N95). But this isn’t the right move for Canadians, Evans and Salt say, as we need to save respirators for workers in need. “They're incredibly short in supply, and we need to preserve them for healthcare workers who are actually dealing with COVID-19 patients in hospitals,” says Evans.

Do you think that the Public Health Agency of Canada will update their guidelines to recommend double masking?

“They may very well do that,” says Evans. “[Double] based on the idea that the more layers you have, the better the mask is at preventing transmission of droplets.” However, he says that the most important thing for people to do right now is to follow the current PHAC recommendation of a three-layer mask.

“We're learning a lot as this pandemic evolves, [and] there's been so many changes just in the course of this one year that I would never have expected,” says Salt, adding that we should rely on results from scientific studies to inform our next steps.

Is double masking better in protecting from COVID-19 variants?

Not necessarily. Salt says we should stay focused on following the public health recommendations that are already in place: stay home when you can, physically distance, wash your hands and wear a mask. This includes wearing a mask outdoors, when you’re not able to reliably keep at least two metres of distance from other people. “Whatever mask you choose, wear it properly [and] don't touch your face. If PHAC’s recommendations evolve to something different, then we can look to how we can adjust again.”

Evans says the current health guidelines, if followed properly, are effective in avoiding infection from the variants. “The variants aren’t trickier; they're not able to move around a mask better than [the]. I would reassure people that they just need to continue the measures that they're currently doing, and have been doing over the [past] year. There's nothing about the variants that would make me jump out at the moment and suggest any additional measures.”

Are there any downsides of double masking?

Too many layers can be uncomfortable and could even make it hard to breathe, both Salt and Evans note. This might lead to people adjusting their masks frequently, which puts them at higher risk of contamination. “Adding more masks [makes] it difficult for the person to breathe normally, and as a result, the person might start sweating [or] adjusting the masks on their face throughout the day because it's not comfortable,” says Salt. “In my opinion, it would be better to have one mask that works well, rather than starting to add multiple masks.”