Mask up! How to choose and maintain the best masks for use against COVID-19

As the United States enters into the colder months and record-high daily cases of COVID-19 continue to be broken on successive days, finding the best mask for your needs is more important than ever. Wearing something is always better than nothing, but unfortunately, finding masks that meet WHO and CDC guidelines isn’t a particularly easy or fruitful endeavor. It’s not hard to meet these recommendations, but researching and compiling the best masks on the market for a range of different needs proved that few manufacturers do. Fortunately, there are some.

We’ve written at length on the current pandemic, how it’s been handled, and how best to handle yourself through these discombobulating times. This article will hopefully serve as a useful refresher on some of those topics, particularly the latest science on masks, how to use them, and what to look for when buying them.

Based off criteria from the CDC and WHO, we’ll also highlight a few options that should help keep everyone safe, whether you’re an outdoor runner, hard of hearing, or just in need of a quality reusable mask.

A note on the science of face masks

As a disease that has only come to our knowledge in the past year, the epidemiology and pathology of COVID-19 is still relatively nascent compared to pathogens we’ve had decades, or even centuries, to study. As much as we at Ars wish we could contribute to pushing this research further along, we don’t have the tools to research various masks and their impact on COVID-19 transmission as deeply as we (and the entire scientific community) would like to. As such, we’re reliant on the latest scientific discoveries and the long-understood knowledge that, generally, a proper mask limits pathogens from entering or escaping the respiratory system where they can be absorbed and expelled.

Historically, the science behind mask-wearing has consistently pointed toward having a positive effect on slowing/preventing transmission of airborne diseases. For some of us, that’s all we needed to know when it came time for the public to adopt transmission-slowing measures during the current COVID-19 pandemic. But, at first, leading health organizations like the WHO and CDC both had trepidations about recommending universal masking.

In summary, the reasoning against wearing them boiled down to absence of evidence (though this is not the evidence of absence, as mask efficacy against COVID-19’s community spread has yet to be studied thoroughly), supply shortages for health care workers, and the fear of masks providing a false sense of security to the detriment of the public’s adherence to more important aspects of reducing transmission, like social distancing, limiting gatherings, and diligent hand-washing.

By now, with the exception of maintaining health care workers’ supplies, the scientific community largely maintains that the effect of wearing a mask in public overcomes these hesitations and is a crucial component to slowing and—hopefully, one day—eradicating the COVID-19 pandemic. As for the only remaining concern, shortages for health care workers, that’s where the use of cloth masks comes in.

Shouldn’t this list just be N95s or KN95s?

Not exactly.

According to WHO mask guidance, if you have COVID-19, COVID-19 symptoms, are caring for someone who may be infected, or are among the vulnerable population (aged ≥ 60 years, people with underlying comorbidities, such as cardiovascular disease or diabetes mellitus, chronic lung disease, cancer, cerebrovascular disease, or immunosuppression) then a medical mask, such as an N95 or KN95, is the safest bet to protect yourself from the virus or contain the spread if you have it.

Similarly, if you’re in a living space with or are caring for someone who has or may potentially have COVID-19, these medical masks are the only proper equipment. Concurrent use of a cleanable face shield is highly advisable when in close contact with the patient in an effort to increase your safety and prolong the effectiveness and integrity of your mask. Placing a surgical mask over the outside of the N95 or KN95 while wearing it can also help preserve it. Social distancing and frequent hand-washing are also to be employed. For more information on caring for COVID-19 patients, check out the CDC’s guidance.

Limit your exposure

But if you’re not in one of these situations, properly specified non-medical masks, along with social distancing, should do the trick.

In this case, “the trick” is limiting your exposure to (protection) and ability to spread (source control) the virus. Ultimately, the potential for reaching a critical amount of exposure, or viral load, needed to infect you (or for you to infect others) is greatly reduced by keeping at least 6 feet of distance from others, wearing a face covering, and avoiding poorly ventilated, indoor environments.

For healthy individuals in this context, cloth masks that don’t meet N95 filtration standards seem to be effective in protecting people during their day-to-day, necessary tasks. You can read more about these studies in our deep dive on mask data, but, in outdoor, well-ventilated settings, cloth masks that follow the WHO/CDC recommendations should be sufficient to keep yourself and others safe.

Global shortage

This, taken with the ongoing global shortage of medical masks, widespread availability of fabric ones (and therefore higher adoption rates), as well as the washability and reusability of these means that cloth masks are generally the best option for the healthy public.

If you need KN95 or N95 masks, bear in mind the global shortage, factor in your needs and use habits, and make that judgement accordingly. In other words, if you’re a not a high-risk individual and are in public settings frequently, the sustainability of buying that many medical masks will contribute significantly to the already critical strain on PPE (personal protective equipment) availability for health care workers, patients, and vulnerable populations as the pandemic continues to surge.

If you’re in a situation like mine—I have high-risk family members and therefore have been in public so little that, on average, six KN95 masks last me a full year (using each no more than five times, not to exceed eight hours of total use on each mask, per the CDC’s crisis-level shortage provisions for health care workers)—then perhaps these may be a feasible option for you, as well. Surgical masks that are not N95 or equivalent have not been approved by the CDC for reuse, due to their fitment and lower level of filtration.

There are, of course, advantages to both medical and fabric masks depending on your needs. Naturally, the long-term reusability of cloth masks is their biggest strength. To ensure long-term safety, those masks should have some key features.

How to choose a mask

When shopping for a good cloth mask, there are a few dos and don’ts to keep in mind, put forth by the WHO and CDC. Here’s the summary.

DO

• Look for masks with at least three layers as outlined below—the more the better.
  • An innermost layer made of hydrophilic (water-absorbing) material (cotton or cotton blends).
  • The outermost layer made of hydrophobic (water-repelling) material (polypropylene, polyester, or their blends).
  • A hydrophobic middle layer of synthetic non-woven material such as polypropylene or another cotton layer which may enhance filtration or retain droplets.

• Ensure a good fit with a tight seal. Form-fitting wires in the nose bridge are especially helpful.
• Make sure it fits snugly but comfortably against the sides of the face and completely covers the nose and mouth.
• Choose masks secured with ties or ear loops.
• Make sure it allows for breathing without restriction.
• Select materials that can be laundered and machine dried without damage or change to shape.

DO NOT

• Don’t get valved masks! They put others at risk.
• Don’t use fabrics coated in wax or other similar compounds on any layer of the mask as these can block the mask’s pores for air flow, creating more air passthrough around the sides of the mask.
• Don’t get masks made of stretchable fabrics as these increase pore size as they stretch.
• Don’t use neck gaiters for the following reasons:
  • They’re typically made of stretchable fabric.
  • Often they don’t have the proper number or types of layers.
  • It’s hard to keep track of where the front is to avoid touching it.

Sticking to these guidelines will help to ensure efficacy, reusability, and safety for yourself and others.

Mask hygiene: How to wear a face mask (and take it off).

Putting on, or donning, a clean mask is a relatively simple process. First, wash your hands for at least 20 seconds, then, holding the ties or ear loops, put the mask on your face and ensure a good seal around the nose bridge, cheeks, chin, and sides of your face.

While you’re wearing the mask do not touch the front of it, as there can be viral particles on the surface. By now you’ve likely heard not to touch your face (or nose, mouth, and eyes) to avoid potential infection via fomite transmission of the virus, caused by touching a surface that may be contaminated with it and introducing it to your body. While wearing your mask, the front of it especially should be treated as a potential fomite (source of transmission), so ensure proper fitment when putting it on initially to avoid having to touch it while wearing.

This continues when you’re taking off the mask, or “doffing” it, as well. Grasp only by the ear loops or ties, undo them, and remove the mask downward off your face, taking care to avoid contact with the front of the mask. Immediately place your mask in the wash after wearing; it’s fine to put it with other high-temperature washable clothing (more on this in the next section). If you’re unable to launder the mask immediately, make sure to fold it inward so the inner part (where your face was touching) is facing out and place it in a single disposable bag until it can be washed. Wash your hands for at least 20 seconds directly after doffing the mask.

You should not be donning and doffing your mask multiple times throughout one wear. Masks should be washed or sanitized after every use. For this reason, it’s helpful to have multiple masks to suit your wearing habits so you’re never wearing a contaminated mask. Any masks exposed to outside liquids or other damage should be taken off and discarded as soon as it’s safe to do so. If the layers of fabric look noticeably worn out or you notice any holes forming, discard the mask.

To summarize:

• Before putting on your mask, wash your hands for at least 20 seconds.
• Secure the mask on your face and ensure a snug, breathable fit with the best seal possible.
• Do not touch the front of the mask while wearing it or take it on and off multiple times throughout wearing.
• Take the mask off by the ties or ear loops and put it directly in the wash.
• OR place it in a disposable bag until it can be laundered.
• Wash your hands for at least 20 seconds after taking off and laundering/storing your mask.

How to wash a face mask

Generally speaking, you should follow the washing or sanitizing instructions provided by the manufacturer of your mask. Do not put masks in microwaves, ovens, or attempt to use UV light to sanitize your mask. These are neither safe nor effective ways to kill all the germs on your mask. There are currently no consumer products on the market—UVC-emitting, heat-radiating, or otherwise—that can achieve sterilization of any type of mask.

If you don’t have laundering instructions for your mask, here are some general guidelines you can follow to wash your fabric mask safely and effectively.

Machine-washing

• If machine-washable, include your mask with your regular laundry.
• Use regular laundry detergent and the warmest water the materials permit.
• Ideally, your mask’s materials should be able to withstand 140° Fahrenheit (60° Celsius).
• Non-woven polypropylene may be washed at high temperature, up to 140°C.
• Masks composed of non-woven polypropylene spunbond fabric combined with cotton can tolerate high temperatures and can therefore typically be steamed or boiled.
• Wash these masks delicately without too much friction, stretching, or wringing.
• If hot water isn’t available, wash with soap or detergent and room-temperature water, followed by either boiling the mask for one minute (if made of the proper materials) or soaking it in 0.1 percent chlorine for one minute, then thoroughly rinsing with room-temperature water to avoid any toxic residual of chlorine.

Washing by hand

• Use bleach containing 5.25 percent–8.25 percent sodium hypochlorite. Don’t use bleach outside of this range or if it’s not specified.
• Check the label to see if the bleach is intended for disinfection. Some bleach products, like those made for color-safe use, don’t meet the needs for disinfection.
• Don’t mix bleach with other cleaners.
• Ensure adequate ventilation during use.
• Wear skin protection and consider eye protection for potential splash hazards.
• Prepare a bleach solution by mixing:
  • 5 tablespoons (1/3rd cup) of 5.25 percent–8.25 percent bleach per gallon of room-temperature water
  • OR 4 teaspoons of 5.25 percent–8.25 percent bleach per quart of room-temperature water
• Soak the mask in the bleach solution for 5 minutes.
• Pour the solution down the drain and rinse the mask thoroughly with cool or room-temperature water.

Drying

• Use the dryer’s highest heat setting and leave the mask in until completely dry.
• OR allow mask to air dry completely, placing in direct sunlight if possible.

After washes, make sure to inspect the mask for any signs of damage or developing holes. Like anything made of fabric, over time, it will start to degrade. Staying vigilant here will let you know when it’s time to get a new mask, especially if the manufacturer doesn’t state an estimated lifetime.

How to reuse disposable masks responsibly

If you need to use KN95 or N95 masks, you can reuse them for up to five total uses, not to exceed eight hours collectively as per CDC guidelines designed for health care professionals in pandemic circumstances. Studies show that, after five uses, the integrity of the mask (its fitment in particular) has degraded beyond a safe point for use. Same goes for anything above eight hours of total use. To ensure integrity, users should perform a seal check with each reuse.

If you’re following these procedures, then a rotation policy that allows for at least a week between each mask’s use, while storing them in individual breathable paper bags in the interim, is highly advisable. This helps to limit the potential for fomite transmission from a contaminated mask while extending the use of your N95 or equivalent.

Medical masks aren’t rated for duration of use, as they’re manufactured to be used once and disposed of once taken off. But the CDC indicates that following these guidelines, as well as those outlined above for taking off PPE safely, can allow users to safely utilize the same mask on multiple occasions before disposing.

Searching up methods for sanitizing disposable masks will bring some results, including FDA-approved (via emergency use authorizations) and CDC/NIOSH (National Institute for Occupational Safety and Health)-endorsed methods for health care facilities to do so, specifically in the face of crisis-level respirator shortages.

Crucially, only certain health care facilities have the proper tools to effectively use these minimally studied strategies for sanitizing disposable medical masks. Not only do these provisions require specific, lab-grade tools and fastidious application, but they were drawn up for use in the event of worst-case-scenario shortages, where health care workers must use such methods to provide themselves some level of protection against known infected individuals. Bottom line: don’t try to mimic this at home (or in public), because you can’t.

As we previously stated, there are currently no consumer products on the market—UVC-emitting, heat-radiating or otherwise—that can achieve sterilization of any type of mask. This gives washable cloth masks a huge advantage for the public.

Our top pick for an all-around face mask

The best mask to limit COVID-19 transmission is the N95 respirator. When we say “best all-around,” this means the best mask for the largest amount of people—healthy, low-risk individuals, in particular.

What makes Kenneth Cole’s Premium Cotton Face Mask our top all-around recommendation is the rare characteristic of not only meeting but exceeding best practices from the CDC and WHO.

With six layers, composed of an inner cotton layer, four non-woven filtration layers, and a moisture-controlled antibacterial outer layer, these masks check all the boxes—some of them multiple times. The antibacterial finish, as you’ll find on any mask touting this feature, isn’t certified to kill the SARS-CoV-2 virus at this point, but it is EPA registered and effective for at least 30 washes at 140°F.

HeiQ—the chemical manufacturing company specialized in treating fabrics and textiles that makes the treatment—says the coating will kill 99.9 percent of SARS-CoV-2 in 30 minutes, a claim they can’t make in the US without pesticidal registration, which they don’t have. Ultimately, this may amount more to killing microbes that prevent odor than preventing infection, so the filtration layers are the important bits here.

The masks are also machine-washable and have a nose clip to form-fit along your nose bridge and cheeks. This is advisable for any mask wearer but is particularly helpful for glasses wearers as this better fit works to prevent fogging up your spectacles.

Kenneth Cole’s Premium is not the only worthwhile mask, but as far as cloth masks go, it is an exemplary representation of all the CDC and WHO’s requirements. Due to its fit and adjustability (which facilitates minimal air escape), we’d also recommend this as the best mask for glasses wearers, though any on this list should do well for the same reasons.

Great masks with a replaceable filter

Adding a replaceable filter to a cloth mask can be a better long-term solution for maintaining a high filtration integrity versus relying on the integrity of your mask’s filter throughout multiple washes. As any breathable material begins to wear, filtration inevitably becomes affected by this. While you should still remain vigilant for signs of wear on masks with replaceable filters, the ability to swap in brand-new filters with each use means you won’t have to question the integrity of your primary filtration layer. We have two selections here—one with a disposable filter and another with a washable one, though the former meets a higher filtration standard.

The Face Mask Kit by Outdoor Research uses filters made of non-woven polypropylene, which is the same material used in medical masks. They meet the ASTM F2100-2019 standard for filtration efficiency, which means they’re rated to filter out greater than 95 percent of bacteria sized 0.1μm or bigger. SARS-CoV-2 viral particles can range in size from 0.5μm to less than 0.1μm. PM2.5 filters, which are commonly sold online for those sensitive to air pollution, won’t be very effective—they only filter out particles up to 2.5μm.

The ASTM F2100-2019 standard also tests for differential pressure (the amount of air escaping or passing through the filter), flammability, and resistance to synthetic blood penetration. Outdoor Research’s filter meets or exceeds all but the test for blood penetration, which is made specifically to simulate a patient’s artery or vein bursting onto the mask—a highly unlikely situation for members of the general public to find themselves in.

The company says its filters can be used for around five to seven uses and are not to exceed 40 hours in a week, depending on humidity, face makeup, facial hair, and sweat. Per CDC guidelines on reusing medical masks, if not washing the Face Mask Kit every day, implementing a rotation policy using multiple masks with at least five days in between wears could be a useful strategy to prolong their filters’ life span, rather than attempting to wash the mask every day and transfer the partially used filter into the freshly laundered mask.

The Outdoor Research masks should always be worn with the filter inserted, as there are only two layers of polyester that comprise the mask otherwise. While this material is great for breathability and water repellence—two qualities the WHO recommends in a mask—its filtration efficacy alone won’t provide much protection without the filter. In combination with the disposable filter, though, the polyester’s low moisture retention and therefore higher electrostatic properties could help catch aerosols. Three filters come with the mask, and replacements can be bought in relatively inexpensive three packs.

The face mask without the filter is machine-washable at high temperatures, which is another great plus, and it’s treated with HeiQ V-Block, which is rated to kill 99.9 percent of viruses and bacteria in 30 minutes (though, as we mentioned, this hasn’t yet been confirmed to kill SARS-CoV-2). This protection starts to diminish after about 30 washes, but it’s unlikely you’ll experience much impact from this; you should always avoid touching the front of your mask anyway.

Also a good option

If you’d prefer a mask with many of the same qualities but with a machine-washable filter, Primal Wear’s Carbon Face Mask 2.0 is a solid option.

Its filter doesn’t meet as high a standard of filtration as Outdoor Research’s, though. The in-house developed NT3D filter is rated to strain out 97 percent of particles 0.4μm in size, as opposed to the 95 percent filtration of particles sized 0.1μm or bigger on the Outdoor Research mask. Developed in partnership with the Korean Apparel Testing and Research Institute and tested to Korea’s FDA standards, testing showed Primal Wear’s filters were able to retain greater than 80-percent filtration after 10 washes, so plan your use accordingly. One filter comes with the mask, but you can buy five-packs of replacements.

The mask is composed of two layers of polyester and a nanofiber-treated polymer makes up the filter piece. Just like the Outdoor Research mask, Primal Wear’s should not be worn without the filter inserted. The front layer is constructed of a carbon and polyester blend, and the back is made with cotton and polyester. The carbon/polyester weave is an evolution of Primal Wear’s original Face Mask 2.0, adding carbon for antimicrobial properties mostly related to odor, while the inside layer uses the more hydrophilic cotton blend.

The design of the Carbon Face Mask 2.0 is well-considered, using a washable plastic component to keep the mask tented off of your face, thereby increasing its breathability and filtration while limiting how much air is forced out of the sides. It’s placed within the mask itself, so it relies on the tension of placement in the mask rather than pushing against your face.

This kind of design can also be useful during exercise, but a more dedicated mask can be a better choice for such activities.

A great mask for runners and exercisers

For those who need a comfortable, breathable, water- and sweat-resistant mask that doesn’t get sucked into your mouth during light or heavy exercise, the UA Sportsmask developed by Under Armour is the perfect fit.

Composed of three layers, the UA Sportsmask has a water-resistant polyester outer layer, a 100-percent polyurethane middle, and a soft, smooth inner layer made of 77-percent nylon and 23-percent spandex for wicking away moisture. It’s also machine-washable.

The structure of the mask also ensures that it sits raised off of your face and lips. Not only does that arrangement enhance breathability and maximize filtration efficacy, but it also provides excellent comfort by avoiding contact with sweaty skin, and it prevents the mask from being sucked in during heavy breathing. The form-fitting nose piece and stretchable ear-loops bolster these aspects while providing a snug fit for limiting air escape.

We’ve seen the UA Sportsmask frequently mentioned as a top pick in running and exercise communities, and with all its safety bases covered, it’s a great choice from a usability and efficacy standpoint as well.

Great masks for people hard of hearing

A unique issue now facing people who are deaf or hard of hearing is the inability to lip-read somebody wearing a mask. Ideally, in such situations, it’s best to use handwritten communication, text (or speech-to-text features commonly found on phones and app stores), or ASL. Obviously, pulling down your mask to communicate is not safe, and face shields are not sufficient replacements for masks.

Instead, the CDC recommends the use of clear masks if you’re regularly communicating with people who have hearing impairments or otherwise rely on facial expressions and cues regular masks hide. Masks made solely of clear materials like vinyl are next to useless, but a cloth mask with a small window of clear material can be a good option.

Generally, a mask without a clear window is optimal for situations when you don’t need a clear window—that’s because clear windows can create slightly more air pressure within the mask, contributing to more air escaping through the sides. However, if you’re a teacher or caretaker, for instance, who is required to communicate with people in need of such a solution for long hours, then a windowed mask is your best bet.

Windowed masks are still a relatively new market for mask makers, and as such, you won’t find many that meet CDC/WHO standards from big manufacturers or your typical marketplaces like Walmart and Amazon. Instead, it has become incumbent upon the craftier among us to help meet this need and do so up to spec. The CDC has released guidelines on how to create good masks at home, but, if you’re not particularly handy, your best bet may be to pick a mask that exceeds these standards and is made by someone with nimble fingers.

The Clear Window Mask by Deluxemask tops our picks thanks to its three-layer cotton design, built-in nose wire, and adjustable straps. We also love how its large window area doesn’t take up too much of the mask’s sides, where fabric is preferable. Machine-washing this or any other mask with a clear window is not recommended, but hand-washing is entirely suitable. Fog protection on a Clear Window Mask is solid, but, if that does begin to wane, you can rub a dab of dish soap, toothpaste, or anti-fog spray on the inside to help prevent fog.

There’s also a nice assortment of styles, from plain to, well, not-so-plain and a few in between. Adults get a one-size-fits-all solution, but another Etsy manufacturer we’ve found, Bonnie’s Crafty Creations, has a similarly great solution for kids with a ton of fun pattern options and all the same safety features we like from Deluxemask. Do note that some of the masks sold by Bonnie’s Crafty Creations offer the option to add vents—something we’ll stress again that you should avoid at all costs.

Great masks for kids

In looking for a mask for a little one, the same rules apply as for yourself. As such, you can choose from any of the above options, depending on your needs, and select a kids or smaller-sized option. Most manufacturers’ sizes in small/medium fit children, while the majority of adults should fit in large/extra-large offerings.

If you’d like something a bit more playful but still every bit as protective, we think one of the window-less options from Bonnie’s Crafty Creations is a solid bet. Styles range from superheroes, to school subjects, and to animated characters of all kinds, so self-expression shouldn’t be an issue here.

Even better, these masks have two layers of cotton sandwiching a third layer made of Pellon, a 100-percent polyester material. They also feature an adjustable nose wire and are machine-washable for ease of wear and maintenance. Some of these have options to add valves, but we can’t stress enough how important it is to avoid using such masks.

If you require N95 or equivalents

As we, the CDC, WHO, and most any health organization have stressed before, medical-grade masks need to be preserved for health care workers and should only be used by them or high-risk individuals—especially as the virus continues to surge and shortages persist.

If you’re part of the high-risk population that needs these masks, you’ll need to make sure to get them from trusted sellers and manufacturers. While N95s in particular are extremely hard to find and often quite expensive, KN95s have been FDA-approved for emergency use during the pandemic. The agency keeps a rather expansive list of brands the FDA has approved and how they’ve fared in cursory testing, which you can reference to ensure quality and legitimacy.

You can either attempt to search out a few specific brands or, if you come across masks elsewhere, use this list for reference of legitimacy. You may also use the FDA’s list of known counterfeits as a cross-reference. Of course, you’ll need to be vigilant to avoid dubious sellers.

Typical commonsense precautions can help here. To name a few:

1. Don’t ever buy through links in text messages, emails, social media posts etc.
2. If it seems too good to be true, it probably is. Most goods would rarely be discounted below 20-25 percent. Anything more than that would be suspicious.
3. Look at what else the site has to offer. Does it make sense? Does the website name make sense?
4. Use a credit card or PayPal to make purchases. Credit cards have some of the stronger US laws to protect against fraud, while PayPal has similarly solid buyer protections to keep you from having to pay for a bogus purchase. It also enables you to avoid entering your card information on a website. These buyer protections don’t apply to money transfers (i.e., sending cash to an individual PayPal account) but only PayPal’s secure checkout options implemented in verified websites.

Again, as this bears repeating multiple times, these should only be purchased for high-risk individuals who need to be in situations where social distancing cannot be achieved. As the virus continues to set record-high infections and hospitalizations worldwide, do your part to minimize the devastation.

Stay home, wear a cloth mask when necessary, and reserve medical masks for those at the highest risk for infection and mortality.

https://arstechnica.com/?p=1722673