Considering double-masking? We’ve got tips
At this point, we all know how important it is to “mask up.” A new question has come up lately though, namely, is one mask enough?
The “double mask” is trending, especially in the United States, which saw some highprofile folks sporting an extra layer of personal protection to the inauguration, including Pete and Chasten Buttigieg, and National Youth Poet Laureate Amanda Gorman. When everyone’s favourite doctor, Anthony Fauci, was asked about it, he said it was just common sense that two masks would work better than one. Between that and the new, more infectious SARS-CoV-2 variants, we expect sales to boom.
It’s worth noting, though, that the trend is more of a comeback than an innovation. We asked Dr. Catherine Clase, associate professor of medicine at McMaster University, about doubling down on masking up and she quickly sent us this quote from “Droplet Infection and its Prevention by the Face Mask,” an article published over 100 years ago.
“The nurses are instructed to wear 2 superimposed masks, making 6 layers of gauze, when caring for cases of virulent infections when secretions are abundant,” it says.
Not only did this mask protocol predate COVID-19, it even predates the 1918 influenza pandemic and began as part of the effort to protect medical workers from diphtheria and scarlet fever.
“It was the nurses who designed those masks, actually,” explained Clase, also a member of the McMaster Centre of Excellence in Protective Equipment and Materials. “The paper was written by Dr. George Weaver but, when you look at it, you’ll see that the mask design was done by a nurse, Charlotte Johnson, highlighting the role always played by women in managing pandemics and supporting people through pandemics.”
Clase also pointed out that health-care workers in China used 12 to 16 layers of cloth in both the first SARS outbreak (2002-2004) and the early days of this pandemic. These extra layers, though, were to protect people exposed to far greater risks of transmission than most of us. Do we really need to double up just to go out for a walk? Or into the grocery store? Or is one mask enough for these everyday activities?
This probably depends on the type of mask you have. There’s a wide range of masks out there and, even though the gold standard of cloth masks — three layers, one made from polypropylene — has been Health Canada’s recommendation since November, few masks currently on the market live up to that standard. I looked at my extensive cloth mask collection and discovered none has polypropylene, likely because I bought them back in March.
“If somebody has already purchased a number of twolayer masks and they want to wear those as double masks, that’s one way to do it,” said Clase. “Another way is, if you have a pocket mask, you can buy polypropylene fabric and you just cut it into rectangles and use those as a washable filter. You just wash it right in the mask. Hang to dry — it may melt in a tumble dryer.”
A “pocket mask” is a cloth mask with a filter pocket and a slit, so you can insert your own polypropylene fabric. Why do this, instead of buying one with the polypropylene sewn right in? Mostly because the latter are surprisingly hard to come by — I know, I tried. When the Etsy platform demanded payment in British pounds (even though the company was Canadian), I gave up and ordered some polypropylene online and some cloth pocket masks. Not all masks have pockets, so check before you buy, but they’re relatively easily found at local shops such as Narces and Peach Berserk, to name a few.
When I picked up my masks at Tribal Rhythm, they surprised me with a few free filters made with nonwoven polypropylene: the right stuff.
“The words you want to look for are ‘nonwoven polypropylene’ and the word ‘spunbond,’” Clase advised, referring to the material recommended by Health Canada. “Spunbond is a particular kind of nonwoven polypropylene, where the fibres are brought together with tiny little welds that melt the fibres together. The welds give it a dimpled appearance. That’s how the fabric stays together but, in between the welds, the fabric is really crazy and random, and we think that this randomness is what really makes a difference in terms of capturing particles.”
Neat. Clase also said that, aside from looking for the right filter, the most important things are to make sure you have a good, tight seal, with no “edge leak,” and to make sure the mask is breathable so that you’re using it as an actual filter, not breathing out the sides.
“I think what we’re talking about really is people wanting to redouble their efforts with masks, right?” she said. “People want to make their masks as safe as they possibly can and wearing two masks is just a form of layering, so as long as it still fits, I think it’s absolutely fine to put on a double mask as a method of layering.”
She noted, however, that the current Health Canada regulations don’t call for it and that all evidence at this point suggests that one properly fitting, properly worn mask made with nonwoven polypropylene is the current recommendation for those of us who aren’t front-line workers.
“What we should do now, I think, is focus on the good side of the socialization of maskwearing,” said Clase. “In many cultures, mask-wearing is seen as a person taking on their responsibility toward society and as a very positive thing. And so I think we can build on that mantra of ‘your mask protects me and my mask protects you’ to help make mask-wearing a cultural norm and a way of signalling to other people, not fear, but our concern and our caring for others.”
So if you want to do two masks, go for it. Before you do that, though, start by making sure you at least have one that’s up to code. Then maybe you can work your way up to Pete Buttigieg levels of layering.
To read more recommendations on masking up from Dr. Clase and her colleagues, check out clothmasks.ca and their narrative review for the Mayo Clinic.