Most Americans have some type of face covering due to the COVID-19 pandemic. Whether homemade, scarves, bandanas, or purchased at your local store, a face covering is strongly recommended by the CDC and mandated by most local governments. Face masks combined with other preventive measures, such as frequent hand-washing and physical distancing, help slow the spread of the virus.
Many people question the efficacy of face masks largely because our government, as well as agencies like the CDC and WHO, initially stated that masks were not necessary. It’s important to keep in mind that experts were (and are) learning about this new virus in real time. The extent to which the virus could spread was initially unknown, as were specifics about the timing of symptoms and health consequences.
As time has passed, it has become clear that the virus spreads in droplets that can linger in the air for hours. These droplets disperse a few feet from just speaking and breathing. The droplets can spread over twenty feet with coughing and sneezing. Learning this pivotal piece of information is when masks became an important way to protect each other from infection, especially when the virus can be spread by asymptomatic individuals who may not know they are infected. These developments led agencies worldwide to change their positions on face masks, now stating that they are vital in reducing the spread of the virus.
Wearing a mask and spatial distancing are the best ways to combat getting sick. This is a new virus and it is constantly evolving. That’s why we need to stay up on the latest information and guidelines to stay safe. Check local agencies for updates.
Any face covering is better than none, according to experts, but different fabrics and constructs can greatly impact their efficacy. Today we’ll sort through those details.
Materials
You’ve likely seen masks made of every possible fabric, from cotton shirting fabric, to soft synthetic knits and silk. Researchers completed a study including a variety of 32 cloth materials; three of the five most effective at blocking particles were 100% cotton and had a visible raised fiber or nap, such as found on flannels. Four of the five lowest performers were synthetic materials. Tests were done using particulates similar in size to the coronavirus to ensure that results mirrored real-life scenarios.
The level of protection was highly determined by how tightly the fabric was woven. The study found that cotton was most effective due to the “web” type construct of the fibers themselves, which create a field of barriers for particulates that may be encountered (and why fabrics with a visible nap scored a higher protection level). Synthetics, like polyester, were found to be the least effective because of their “smooth” fiber properties that lack the construct to block particles. An important detail in a variety of studies highlighted the benefit of masks constructed of several layers of fabric. Test yours: light a candle about twelve inches in front of your face and try to blow it out through while wearing a mask, if the light wavers, the mask isn’t blocking enough air flow.
Medical grade masks, like N95 masks (which are made of electrostatic non-woven polypropylene fiber) offer the best protection, but due to the limited availability of PPE (personal protection equipment) for medical personnel, experts continue to ask that the general public avoid purchasing these items to ensure that medical providers are adequately protected when in direct contact with the virus.
What About Filters?
Masks with pockets for filters (often made of carbon, PM2.5 material, or polypropylene, for example) did provide a boost in protection. In some instances, depending on the filter, protection from incoming particulates was boosted by up to 30%. But, many experts who have researched which masks provide the best protection warn against using materials like coffee filters. Coffee filters and similar materials are hard to breathe through, so you end up breathing around the filter rather than through it. One researcher explains, “Imagine if you have a hose. You put your thumb over part of it, and the water just goes around it. In this case, the [air] flow will go around that filter,” which defeats the purpose of using a filter, they explain.
Be cautious of masks that state they have NIOSH (National Institute for Occupational Safety and Health) approval. Many are being found to be counterfeits, misleading people about the protection the masks offer. Read here for information from the CDC on how to determine if a mask with such an approval is authentic.
Skip Masks With Valves
Mask valves, available on some masks intended for projects like installing fiberglass insulation, sweeping a dusty garage, and other tasks, are being banned by state and local governments as well as some airlines, because of the risk they pose in spreading the coronavirus.
According to the Mayo Clinic, these types of masks do not protect others from coronavirus, as the one-way valve which allows unfiltered air to be released when the wearer exhales means the wearer can spread the virus as easily as not wearing a mask. “It defeats the purpose,” Kai Singbartl, a medical doctor who is the chair for infection prevention and control at the Mayo Clinic in Arizona. “They are unfiltered, those valves are the path of least resistance so to speak, it’s easier to exhale and get rid of the heat and moisture.” In addition to getting rid of heat and moisture, the valves also allow wearers to exhale “viral droplets and particles,” Dr Singbartl said.
Fit matters
Wearing a mask that does not fit your face snugly will not adequately protect from incoming particles, or protect others from outgoing particles. Ensuring that the mask is properly sized to fit your face, without gaps around the sides of your face or around your nose, is essential in making the most of the protection the mask provides. Masks only provide protection if your entire nose and mouth are covered.
Watch the video below for a quick way to adjust a mask for better fit:
It was recently reported that a variety of face covering, often called a neck gaiter, protects far less than traditional face masks that tie behind the head or use ear straps to be secured. Some reports even speculated that wearing a neck gaiter was worse than not wearing a mask at all.

The study that involved neck gaiters and the ultimate interpretation about their efficacy didn’t explore various factors that could have influenced the results. Some variables include whether the tester was talking louder than while wearing other masks, did the material of the neck gaiter retain moisture, and did the subject have more mucus on their vocal cords at that moment? No previous study has ever identified any face covering that is less effective than no face covering at all. While more studies need to be done to evaluate the efficacy of gaiters, the authors of the study conceded, “Our intent was not to say this mask doesn’t work, or never use neck gaiters,” stating that was not the focus of their research.
If a neck gaiter is the variety of face covering you have available, by all means, wear it. Consider exploring other options, or learn how to make your own mask (even using the material from the gaiter!) in this post that shares several no-sew methods.
Mask Hygiene
Having and wearing a mask is only part of how to protect yourself and others. Mask hygiene- properly caring for your mask to reduce the spread of any particles on the fabric- is just as important. Wash your mask every day, and allow it to fully dry before wearing again. In order to avoid reusing masks or not having one when needed, stock up with several so you can rotate them. Read these guidelines from the CDC on how to best launder face masks (and also how to properly remove masks after use).
Face masks can offer the wearer some protection — though as you can see, it varies depending on the fabrication and fit. No mask will offer full protection, and they should not be viewed as a replacement for physical distancing of at least 6 feet from others, frequent hand-washing and avoiding crowds. When you combine masks with those measures, they can make a big difference.
Masks are without a doubt uncomfortable, claustrophobic, and not enjoyable to wear. I agree- I wear them 9 hours a day. But, they are the best and most formidable way to protect you, your family, and others from a deadly virus. Isn’t that worth saving the next 200,000 souls from dying?
Sources:
-npr.org/sections/goatsandsoda/2020/07/01/880621610/a-users-guide-to-masks-what-s-best-at-protecting-others-and-yourself
-jamanetwork.com/journals/jamainternalmedicine/fullarticle/2769441
-nymag.com/strategist/article/best-face-mask-filters.html
-usatoday.com/amp/5495988002
-cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-to-wear-cloth-face-coverings.html
-ercweb.com/tips/show/what-works-best-natural-or-synthetic-fabric-face-masks
-independent.co.uk/life-style/face-masks-valve-n95-vent-breathing-coronavirus-effective-ban-airline-cdc-a9660266.html%3famp
-theguardian.com/world/2020/aug/18/what-kind-of-face-mask-best-protects-against-coronavirus-covid-19
-medical.mit.edu/covid-19-updates/2020/08/neck-gaiters
-medical.mit.edu/covid-19-updates/2020/08/neck-gaiters