Is your mask effective against COVID-19? Three questions you should ask yourself

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Check your mask for fit, filtration and breathability. Credit: Roman Samborskyi/Shutterstock

 

The emergence of new, potentially more infectious, coronavirus variants has led many people to worry about the effectiveness of their masks in protecting themselves and other people from catching COVID-19. Some experts are recommending people wear two masks in order to increase the protection.

 

Masks have been the subject of much debate since the pandemic began. Today, most governments and health bodies recommend we wear them to prevent the transmission of COVID-19.

 

But not all masks are the same, and not all are widely available. At the start of the pandemic, the global shortage of personal protection equipment, including masks, led to the mass uptake of reusable fabric face coverings.

 

Soon after, in every shop, place of worship, restaurant, public transport and other common areas, different face coverings appeared, and along with them different problems. Now, every day, we see masks that do not fit properly, masks that slip down the face when talking, masks that fog up our glasses or irritate the skin behind the ears, never mind the eternal question of where we should keep your masks when we take them off.

 

Part of the problem has been a lack of official guidance on what makes a good mask. But at the end of last year, the World Health Organization published a guidance document, which addressed three important elements for the factory manufacture of fabric face masks. The guidance sets out minimum thresholds for fit, filtration and breathability.

 

Here, we explain why these three elements are important and why you should think about what mask you wear and how you wear it.

 

Does your mask fit?

 

Face mask fit is critical in order to prevent gaps between the skin and mask so that, when breathing, the aerosols do not get diverted through the gaps, for example those around our nose. This phenomenon is called "leakage." Our research has also indicated that leakage is one of the major problems in mask effectiveness.

 

Leakage is one of the major problems in mask effectiveness. Credit: Henriquez, Cousins Burleigh, MacKay

 

With a diverse range of facial features and profiles, it is easy to see why—a mask design that fits snugly over one person's nose will leave big gaps over another's. The wire embedded around the nose section even when pressed can move and cause gaps when talking and also gaps can form around the cheek and jaw bone.

 

So one of the most important things to check is how your mask fits your face. Is there a lot of air escaping through the top or sides? If so, consider buying a mask of a different size that fits more snugly over your mouth and nose.

 

How does it filter particles?

 

The question of leakage goes hand-in-hand with the ability of face masks to filter out the infectious agents in aerosols and droplets while still allowing the user to breathe properly.

 

To address filtration, we need to determine how aerosols can penetrate through different masks. Masks work by modulating air-flow through the fabric, reducing the number of particles passing through in each direction.

 

Many different materials are used in masks, including cloth, different types of polymers and nanofibers. Surgical masks are made from layers of polypropylene, which is a plastic material.

 

Different cloths have been tested for filtration efficacy with multiple layers of polyester and cotton proving the most effective. So it's worth checking what your mask is made of when purchasing it. Also, don't be too worried about washing your fabric face mask. Preliminary results from our research show that good filtration fabrics actually improve in their filtration ability over time and are effective up to 50 washes.

 

If your mask isn’t comfortable, you probably won’t wear it properly. Credit: Nong4/Shutterstock

 

Is it comfortable?

 

Breathability and comfort are also critical to to encourage people to wear their masks properly.

 

Reports suggest that users can experience headaches, facial itching and perceived difficulty in breathing due to increased skin and air temperature when wearing masks.

 

If our masks are uncomfortable, it's more likely we won't wear them properly, and that can contribute to the spread of COVID-19. So make sure your mask doesn't make you so uncomfortable that you have to periodically remove it, which risks undermining all your good work.

 

Finding the best face mask

 

How do we make sure that we are wearing the best face mask covering to prevent transmission? We have been working with industry groups to address this issue and improve design, assess fabric filtration and raise awareness of the importance of the three key elements.

 

The good news is that our preliminary data shows that reusable fabric face masks and coverings are capable of achieving excellent filtration of particles that produce good seals to reduce the risk of leaks on different facial profiles. The use of reusable face masks also reduces the amount of single-use surgical face mask waste, which is a growing problem.

 

Based on the World Health Organization guidance, and our research, we can say that as long as your mask fits you snugly and comfortably, with minimal leakage, you can feel confident in wearing it, even with the rise of new variants of the virus.

 

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[aum]

Study highlights the best style and fabrics for COVID-19 face masks

 

Credit: Pixabay/CC0 Public Domain

 

 

In the race to stop the spread of COVID-19, a three-layer cloth mask that fits well can effectively filter COVID particles, says a group of UBC researchers.

 

After testing several different mask styles and 41 types of fabrics, they found that a mask consisting of two layers of low-thread-count quilting cotton plus a three-ply dried baby wipe filter was as effective as a commercial non-surgical mask at stopping particles—and almost as breathable.

 

The cloth masks filtered out up to 80 percent of 3-micron particles, and more than 90 percent of 10-micron particles.

 

"We focused on particles larger than one micron because these are likely most important to COVID-19 transmission," explains researcher Dr. Steven Rogak, a professor of mechanical engineering who studies aerosols. "While the COVID-19 virus is only around 0.1 micron in size, it is always attached to something larger, like the droplets produced by breathing, talking and coughing, which are typically in the micron and not submicron range."

 

World Health Organization guidelines recommend three layers for a non-medical mask: an absorbent inner layer near the mouth, a middle filtration layer and an outer layer exposed to the external environment.

 

Mask materials

 

The team recommends specific fabrics for different parts of the mask: double-knit cotton, quilting cotton, knit nylon or polyester satin for the outer layer, and double-knit cotton, quilting cotton or simple-weave silk for the inner layer that sits closest to the skin.

 

Nylon and polyester repel water, keeping harmful droplets from penetrating through to the inner layers. Cotton and silk feel comfortable, breathe well, and wick away moisture. Importantly, fabric construction is important to breathability and filtration efficiency. For example, fabrics such as polyester crepe (finely woven polyester), high thread-count cotton and dupion silk are not very breathable.

 

Dried baby wipes, which can be swapped out, make surprisingly good filters.

 

"Baby wipes are typically made of spunlace and spunbond polypropylene—similar to the types of polypropylene found in medical masks and N95 respirators," said researcher Dr. Jane Wang, a clinical professor in the faculty of medicine.

 

"They are breathable and trap particles efficiently. They're biocompatible, containing minimal preservatives and chemicals that may otherwise cause irritation or breathing problems."

 

Fit is paramount

 

Aside from choosing efficient, breathable materials, it's important to have a good seal around the mask, say the researchers.

 

"Even an N95 mask is going to take in large, massive droplets with lots of viruses if it does not seal against the face. A well-fitted, well-designed cloth mask with a baby-wipe filter will be more effective at filtering 5- or 10-micron particles than a poorly fitted N95 mask," said Dr. Rogak.

 

He added that the highest leak rates are around the nose, chin and the cheeks, and pleated-style masks tend to leak the most.

 

"The mask should not sit flat against your mouth and nose, because it will be less breathable, as there's only one very tiny portion of the fabric actually exchanging air. Even if it's made of breathable material, it won't feel that way. You need to create a bit of an air pocket, with a bigger curvature in front, so that the whole mask is engaged in air exchange."

 

In the end, masking is an intervention aimed at risk reduction, not risk elimination, says Dr. Wang.

 

"For the intervention to be effective, people need to have access to the intervention and to apply the intervention correctly. An N95 mask will not be effective if people are wearing it halfway down the face. Double masking will not be effective if people cannot tolerate it because of overheating, breathability or CO2 retention problems. The focus should always be to wear a mask correctly by choosing a design that offers a good seal around the nose and mouth and to avoid cross-contamination."

 

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[flash48]

No mask is 100% effective against a virus.  If you want total protection, wear a space suit.

[Arachnoid]

In general with regard to the public using masks, they are not to protect the wearer they are to protect other people from the wearer. If you want better protection you need a sealed mask to FFP3 rating or above not one made from hepa filter or stuff like a spare pair of curtains. All that taken into account you can still carry an infectious spore on clothing ,hands or say food packaging which you contract by cross contamination after removing your mask.

 

https://www.ukmeds.co.uk/blog/what-s-the-difference-between-ffp1-ffp2-and-ffp3-face-masks

[mp68terr]

Mask materials, how to wear a mask, leaking, fitting... It's all about wearing the mask on the face. BUT too many people wear their mask half-way, keep it around their neck, attach it to their elbow, etc. before to wear it again: harvesting virus from potentially contaminated places then bringing virus directly to their mouth/nose. Really bad.

First thing first: teach/learn how to use/wear/dispose of masks.