What Types Of Face Masks Are Best For Coronavirus (COVID-19)?


Despite shortages earlier this year, both hand sanitizer and most disposable, single-use masks have become widely available again. But people continue to use a variety of masks to protect themselves, including handmade and cloth masks, surgical masks, and N95 respirators.  

The CDC has continued to recommend wearing cloth face coverings when we’re out in public and emphasize their importance in the fight against COVID-19. However, many people are wondering if they really work, what kind of mask is best, and how to keep them clean. The truth is there aren’t many studies comparing the common mask types: cloth masks, surgical masks, and N95 masks. But let’s look at some of the few studies that have tried to provide some insight below.

Handmade and cloth face masks

The CDC recommends wearing a cloth face covering (such as a homemade mask or scarf) when you’re in public places where it’s difficult to maintain social distancing. These are places where there are usually more people — for example, at pharmacies and grocery stores.

They published these recommendations soon after a research study showed that COVID-19 can travel up to 27 feet through the air in tiny droplets known as aerosols. That’s a lot farther than the 6 feet we’ve been told for social distancing. Aerosols that contain the coronavirus can be formed when someone coughs, sneezes, or simply breathes out. While it’s unclear if cloth face coverings protect the person wearing them from someone who is infected, they do prevent people who have the infection from spreading it to other people.

According to the CDC, cloth face masks should:  

  • Fit snugly but comfortably against the side of the face
  • Be secured with ties or ear loops
  • Include multiple layers of fabric
  • Allow you to breathe freely
  • Be able to be laundered and machine dried without getting warped or damaged

It’s important to also remember the group of people that should not wear face coverings. Children under 2 years old, people who have trouble breathing, and people who are unconscious or are unable to remove the covering on their own should not wear face coverings. In these cases, a face covering could potentially suffocate them. 

The material matters

A recent study looked at different types of materials for handmade face masks (like silk, flannel, cotton, chiffon, and polyester) to test out which could best filter out tiny particles — ones that were much smaller than the particles that carry the coronavirus in the air. They found that a mask with two layers of different fabrics (like cotton-silk, cotton-flannel, and cotton-chiffon) was similar to an N95 mask in this respect. Both blocked about the same amount of similarly small particles from passing through them. 

An important point to note is that the study emphasized proper fit and found that both N95 and handmade masks with gaps between the face and the mask provided far less protection. 

A note about vacuum cleaner bags
Due to widespread sharing of a 2013 study looking at how well different masks work for influenza (the flu), there has been a lot of interest on the internet about making masks out of vacuum cleaner bags. The thought is that because the bags filter out 99.97% of particles in the air over a certain size, they might be good for protection against the coronavirus, too. 

However, it’s unclear whether or not this is safe. ShopVac, a popular vacuum cleaner brand, has issued a statement strongly warning consumers not to use their bags for homemade masks. Again, the CDC recommends that people wear cloth face masks to prevent the spread of the virus.

Surgical masks

According to the FDA, a surgical mask is “a loose-fitting, disposable device that creates a physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment.”

Few studies compare surgical and cloth masks for preventing respiratory infections. In the largest study on the topic, researchers enrolled 1600 healthcare workers and divided them into three groups. One group was given 2 new surgical masks daily. Another group was given 5 cloth masks to use for the duration of the study that they were told to wash after shifts and reuse. The third group was told to continue doing what they had normally been doing, whether that was wearing masks or not. 

Many people have tried to use this study to claim that cloth masks don’t work because after the study was done, the researchers found that those who wore surgical masks experienced fewer infections than those who wore cloth masks. However, there is a big caveat: The study did not take into account many things that could have affected the results, like how well the cloth masks fit each individual, how exactly they were washing their masks, or how often each mask was used. 

While it’s unclear whether surgical or cloth masks are better, it’s important to remember that cloth masks do help in preventing the spread of COVID-19, especially if they’re used correctly.

N95 respirators

N95 respirators (also called “surgical N95 respirators” or “N95 masks”) filter out 95% of all particles over a certain size. One study that looked at N95 masks from different manufacturers found that all of the masks they studied filtered out 95% of particles 0.1 to 0.3 microns wide. This includes the size of droplets that carry the coronavirus.

Again, there aren’t many studies directly comparing the effectiveness of common masks against infections. But in one of the studies we discussed above, researchers found that when masks were worn properly, N95 masks performed better than surgical masks. They also studied cloth masks of different materials (for example, cotton, silk, chiffon, flannel, various synthetics). When those cloth masks were made of only one material, N95 masks performed better. However, when cloth masks used two different materials, they worked about as well as N95 masks.

In order to protect our healthcare workers, the CDC is urging all of us to reserve our national supply of N95 masks for those who are caring for patients with COVID-19 and have a higher chance of getting infected.

Reusing N95 masks

If you have an N95 mask you’ve already used (for example, if you work in construction or purchased them for a hobby project prior to the pandemic), you might consider reusing it, but be aware that it comes with a risk. Reusing a mask could mean potentially infecting yourself with the virus if it’s been contaminated. For this reason, it might be safer to use a cloth mask you can regularly wash, or a surgical mask that you can throw away after use.

The following tips are adapted from the CDC’s recommendations for health professionals on when and how to reuse N95 masks: 

  • Wash your hands or use hand sanitizer before and after touching the mask.
  • Check that you have a good fit and it’s properly sealed to your face each time you use it.
  • Throw it away if you notice any damage or it becomes hard to breathe through.
  • Avoid touching the inside of the mask so you don’t contaminate it.
  • When you take off your mask, put it in a container with a lid and label the container with your name so no one else uses it. If you want to label the mask itself, it’s OK to mark the straps, but don’t use a marker on the front part that is working to protect you.

Recently, researchers at MIT developed a silicone face mask that uses an N95 filter. Unlike N95 masks, it is designed to be sterilized (killing all the bacteria and viruses on it) and reused. If brought to market, it could help ease the N95 mask shortage and keep our frontline workers safe.

How do I wear a mask, and what’s the best way to wash one?

There’s a lot of information right now on how to make a mask. The CDC has published instructions here. You can also check out our video demo here

As the CDC continues to recommend that the general public wear cloth face masks, knowing how to use one correctly is critical. The coronavirus can survive on the surface of masks, so it’s important to learn how to properly put them on and take them off without getting germs on your hands and transferring them somewhere else. Here are some pointers adapted from the World Health Organization (WHO):

Putting a mask on

  1. Put the mask on with the correct side facing out: Some masks have straps that you tie together. Others have elastic bands that go onto your head. Your handmade mask might have elastic loops for your ears. In any case, make sure you’re putting the mask on with the correct side facing out.
  2. Fit your mask to your face: If your mask has a flexible band across the top, press that against your nose and cheek bones to fit the mask to your face. If your mask is made of cloth, pull the bottom edge of the cloth downward to below your chin so that the mask opens up.

Taking a mask off

  1. Undo ties or unhook elastic bands: Untie your mask from the back, or if it has elastic bands, remove those from your head or ears.
  2. Remove the mask without touching the front: The front of your mask could have germs on it. It’s very important not to touch the front of the mask while you are taking it off.
  3. Discard or wash your mask: If you have a disposable mask, throw it away in the trash. If you have a cloth mask, it’s best to put your mask directly in your washing machine or wash tub after taking it off to prevent contaminating other parts of your home.
  4. Immediately wash your hands: This will protect you in case you accidentally touched germs while taking the mask off.

Washing your cloth mask

For cloth face coverings and handmade masks, follow the CDC’s recommendations for laundering. Wash it with water and soap or detergent at the highest-temperature setting possible (according to the manufacturer’s instructions). Then dry it completely. 

Also, just like seatbelts and airbags don’t substitute for safe driving, remember that cloth face coverings are not a substitute for other preventive measures like social distancing and handwashing.

Should I buy a mask or N95 respirator? 

Please reserve medical-grade masks, including surgical masks and N95 respirators, for healthcare workers and first responders. Unfortunately, we’re experiencing a shortage of these masks, and workers on the frontlines are having to improvise and reuse masks to try to stay safe as they help patients.  

As news of the COVID-19 pandemic broke, many people bought masks, and some factories making masks have closed due to the virus spreading, leaving store shelves bare. The demand for masks has gotten so high and the supply so limited that retailers such as Amazon have restricted mask purchases to first responders and healthcare facilities. This is a big reason why the CDC is recommending cloth face masks, and not surgical masks or N95 respirators, for the general public. 

How can I help hospitals and healthcare facilities with mask shortages?

If you have any unused, unexpired masks or respirators at home, those are the most needed and most helpful items to protect our frontline healthcare workers. Consider donating these to your local hospitals and health clinics.

If you work in industries where respirators are common, you might have reusable respirators. Check with your local healthcare facilities to see if they would allow you to loan or donate respirators during this time. Many reusable respirators also protect from contagious diseases like COVID-19 and would be welcome.

Finally, your local healthcare facilities might also be accepting donations of homemade masks. If you like to sew, you can pitch in by making masks. Be sure to check with the facility to see if they have a preferred pattern for you to use, and check any other requirements to be sure they are able to use what you make.