Which mask is better: Cloth masks vs. N95? The answer is one that fits.

My favorite face mask is an elegant number of black fabric – it suits everything, it doesn’t irritate my face and is sold in a relatively affordable pack of three, so I always have a backup. I have an entire collection of cloth masks, as you probably have, patched at random, in bright colors and patterns, usually made at home by a variety of people in my life.

However, as we let our face covers project our tastes while protecting us, there is another element of style that is often overlooked: the fit. And adjustment is extremely important when it comes to the effectiveness of our masks.

Tons of celebrities were seen with their masks under their noses. Notably, members of Congress who promote masking have been seen raising their sliding masks in public.

Cloth masks sometimes lend themselves to poor etiquette: Congressman David Cicilline (D-RI) slipped his to splash into his hand on the C-SPAN, which is, to be frank, horrible. Mayor Nancy Pelosi is known for having masks that match her clothes, but was once photographed in conversation with George Floyd’s brother, with the mask hanging below his mouth. And just after taking office, President Joe Biden’s mask slipped his face in the middle of signing an executive action related to Covid-19. It happens to the best of us. Walk anywhere in pandemic America and you will surely find people messing with their masks.

Doug Mills / The New York Times / Bloomberg via Getty Images

But to really protect you, fabric masks need to have a comfortable fit. And wearing a tight-fitting mask can be more important than ever in the pandemic. As previously reported by Julia Belluz for Vox, a new, more contagious variant of Covid-19, known as B.1.1.7, which is now spreading around the world, should make us even more cautious about our risk of exposure to the virus, especially indoors.

Mask fit really matters

Proper use of the mask remains a key factor in preventing coronavirus transmission. The sliding of the mask can leave the user extremely vulnerable, since the nasal passage is a common gateway for the virus to enter the body. According to a study in Nature Medicine, the virus binds to certain proteins found in the nasal passage. In fact, there are more of these proteins in the nose than in the lungs, which makes exposure of the nose a serious threat. You do not want any viral particles to reach your nose, so it is imperative that your mask is tight.

Cloth masks are still good for the general public to wear, experts say, so don’t feel like you have to rush out and buy a medical-grade mask like an N95. We think about how our masks look every day, but we are ignoring the importance of proper fit. There is not enough emphasis on what makes a mask well-adjusted and effective – we get distracted by the design, when in fact we need to worry about how comfortable our masks are and whether they are safe enough to trust or not.

The Respiratory Protection Engineering Task Force, a research group based at the University of Cambridge, investigates the effectiveness and enhancement of facial masks and civilian tissues. “What we found in our research is that the actual filter material is not as important as the fit. To get any benefit from a high filtration material, you need to have adjustment, ”said Eugenia O’Kelly, a doctoral student who leads the group. O’Kelly emphasized that without highly specialized machinery, there is no way to be 100% sure that your mask fits, but there were tips for better fit and protection.

According to your team’s tests, double masking can be useful. “Remember that you don’t end up numerically doubling your protection by layers of masks. I’ve seen this kind of ‘math’ online a lot, but unfortunately, that’s not how depth filtering works, ”she said. But bending can ensure that you get a better seal around your nose and mouth than a mask alone, which can be a little loose.

O’Kelly says there are two methods that scientists use to find out if a mask fits. “You can have a quantitative adjustment and a qualitative adjustment. In quantitative adjustment, you measure the amount of particles inside and outside the mask, ”she said. Most surgical masks do not fit well enough or are made of material without sufficient filtration, so they do not pass.

Quantitative adjustment can be expensive because it requires specialized hospital equipment. “More common is the qualitative adjustment of the mask,” she said, for which her team is experimenting with the use of aroma diffusers as a test. If you are wearing a mask and can taste the particles through it, it is a sign that your mask does not fit.

To identify whether your mask is good for protecting others, O’Kelly recommends avoiding masks with the following characteristics:

Fine materiall: If you can see any space between the fibers when you hold it against the light, it is a sign that viruses can pass.

Single layer: If your mask has only one (or even two) layers of fabric, the filtration is unlikely to be high. The best masks have multiple layers or have a pocket to insert a filter, such as a PM 2.5 or HEPA filter.

Poorly adjusted: Fit is very important to the success of a mask, as you can read in this recent study. You may not be able to get a mask that fits perfectly, but the more and bigger the gaps you see, the worse the fit. This can be more important when protecting the user than others.

Discomfort: If the mask is very uncomfortable, you are less likely to use it correctly and more likely to touch the outside of the mask or adjust it while you are away from home.

So, how should a mask fit? “The mask should be a good fit over the nose and mouth, but not too tight to make breathing difficult. It is not intended to filter all the air you breathe, but rather to prevent the droplets in your mouth from spreading into the air, ”said George Abraham, chairman of the Council for Infectious Diseases of the American Council of Internal Medicine.

There is not much we can do to prevent a mask from falling off – except, perhaps, trying to find a mask that fits best.

O’Kelly also recommends doing an adjustment check, although there is no reliable way to currently assess the fit of fabric masks. “Move your hand around the edges of the mask where it makes contact with your skin and see if you can feel any air. If you feel the air, there is a gap, ”she said. But just because a mask has a gap does not mean that it is totally ineffective. It just means that you are not providing the maximum level of protection possible. According to O’Kelly, a fabric mask with adjustment problems can protect the user from more than 50 percent of the particles, and well-constructed fabric masks with gaps can still filter out over 75 percent of the particles.

In a consumer report William Schaffner, professor of infectious disease medicine at Vanderbilt University School of Medicine, recommends tightening the mask if it slips down your nose. You can adjust the strings and make sure there is no air space on the sides. Our best bet is to select a mask that fits correctly: comfortable around the nose and mouth, with no cracks on the sides. A wire bridge mask for the nose can help to shape the mask to the face. Studies from the Respiratory Protection Engineering Task Force found that a metal nose band can improve fit. However, in less structured or elastic masks, this nasal band can also impair performance, so the user must make an assessment.

But shouldn’t we just buy N95s?

As comforting as the fabric masks are sufficient, the United States is far behind countries like Austria, where the government provides FFP2 masks to citizens, and Taiwan, where the government provides high-quality masks to citizens who are likely to go to fit better than some of the circulating cloth masks. Why can’t the same happen here in the United States?

The argument for the government to supply masks is not a new one. It may be good for Americans to have a better PPE, but there are a number of caveats that come with wearing tough masks like the N95. In an e-mail, Abraham told me that it would be difficult for the government to ensure that everyone had an effective N95. “The user needs to pass a ‘fit test’ so that the mask used is not leaking, but forms a good seal on the face, or else the filtering capacity of the mask will be lost,” he wrote. “As a practical reality, this is not consistently possible with the general public.”

There are ways to test the N95 – “you can place both hands around the edge of the mask, once on your face, and blow hard. If you feel air in your hands, you know that the mask is not quite tight, ”explains Abraham. But, according to experts, it is also not 100% accurate.

N95 masks are mandatory for healthcare professionals because they are great for long-term situations, but they can be excessive for short-term use, according to Abraham. An N95 mask may be more appropriate for a long plane ride, for example, rather than a quick run to the supermarket. “The use of the mask would be inconsistent, without doing an adjustment check every time,” said Abraham, and it would be “prohibitive and would do little.” The government could not regulate the use of N95 by all civilians, and respirators would be useless if they were not adequate.

While research by O’Kelly’s group on mask materials is still being reviewed by experts, she says that even a mask with little adjustment is better than not wearing any. “If you can see a gap, your mask is probably not working 100 percent. However, this certainly does not mean that the mask is useless if there are gaps. ”Any kind of gap can compromise the effectiveness of a mask, so it is important to try to ensure that there are no spaces, if possible.

So the next time you pull on your face mask all day, consider finding another style or model that might work best. For extra protection, spend a little extra money to get a mask with a pocket to add a PM 2.5 or HEPA filter, and buy several masks that you can put at home. The sliding of the mask torments us, but if we work on it, we can repel the plague itself. It may be necessary to try and make mistakes, but it is worth getting it right.