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Last updated April 1, 2020. 6 minute read

How useful is a mask in reducing coronavirus transmission?

Linnea Zielinski Written by Linnea Zielinski
Reviewed by Dr. Mike Bohl, MD, MPH

Here‘s what the CDC is recommending regarding personal protective equipment (PPE) including masks and respirators.

“Facial masks are effective, but they do not provide full protection,” says Dr. Patrick Kenney, DO, FACOI. Kenney is double-board certified in Internal Medicine and Infectious Disease and a faculty member of the Cleveland Clinic Florida in Weston, FL in the Department of Infectious Disease. He adds that “masks do help provide a shield from respiratory droplets, but they are most effective when they are fitted to your face to provide an adequate seal.” Although the main function of the mask is to prevent transmission by blocking these droplets, there’s an additional benefit to wearing them: “Face masks also may help a person not touch their face, which is another way viruses can spread if introduced to mucous membranes in the oral cavity, nasal passages, or eyes.”

But it’s also not as easy as simply picking up the first face mask you can find. “Standard flat face masks are effective for pathogens with a heavier molecular weight such as influenza or pertussis,” Kenney explains. But ideally, you want a different type of mask for the coronavirus. “Rounded, fitted masks such as an N95 respirator provide the optimal protection,” he says. There are also different sizes of the N95 respirator available, so it is best to get the right size for you. Additionally, things like having facial hair may disrupt the seal and make the mask less effective. It’s also important to remember that these masks, regardless of type, are not meant for repeated use. Kenney advises disposing of the masks after being in a crowded area or after being in contact with someone coughing or sneezing, because the outside of the mask may be contaminated with pathogens.

The different types of masks

If and when health experts advise United States citizens to wear masks, you need to know what to look for. The U.S. Surgeon General has urged most Americans to not buy face masks to ensure healthcare professionals would have access to them.

Surgical masks

These flat masks, with bands that hook around your ears, do not provide adequate protection from the coronavirus because they do not create a seal. The sides are open, leaving space for pathogens to enter. These masks mostly provide protection for other people from you since they’re directly blocking respiratory droplets that may come from your mouth or nose.


It’s worth noting that there are multiple-use respirators, but this is not the type you want for protection against the coronavirus. Pathogens such as the coronavirus will cover the outside of the mask, meaning you’d need to disinfect the outside of the mask—and do so outside of your home or apartment, since bringing it inside to clean it could infect where you live. The safer option for preventing the spread of coronavirus particles that may be clinging to the outside of these masks is single-use respirators. There is a specific protocol for putting on and taking off these masks to ensure there’s no contamination (more on that below).

Respirators are named with an alphanumeric coding system, so you’ll see one letter with numbers following it. The letter on respirators stands for how resistant to oil it is, and the number stands for what percentage of airborne particles it can filter out in worst-case scenario testing. There are three letters and three numbers you may see on respirators:

  • Letters:
    • N = not oil resistant
    • R = oil resistant
    • P = oil-proof
  • Numbers
    • 95 = 95%
    • 99 = 99%
    • 100 = 99.97%

Make sure your mask is approved by the National Institute for Occupational Safety and Health (NIOSH). There are people attempting to sell surgical masks as N95 respirators on third party retail sites such as Amazon, so always check that you’re buying from a reputable company. The Centers for Disease Control and Prevention (CDC) recommends masks of at least N95 rating for healthcare workers coming into direct contact with people infected by the virus (Frequently Asked Questions about Personal Protective Equipment, 2020). But again, the CDC does not recommend the use of respirators for the general population but rather standard preventative measures such as proper hand hygiene.

Where should you wear a mask?

It is not suggested that most people in America wear masks other than healthcare professionals. People who have confirmed cases or are family members living with someone with confirmed COVID-19 should wear masks to avoid passing the virus to one another. But the Surgeon General urged the general American public to stop buying masks on February 28, 2020, on Twitter, underscoring that continuing to buy masks could prevent healthcare professionals from getting the masks they need in order to care for sick patients safely (Surgeon_General, 2020).

How to safely put on and take off a mask

It’s essential that you remove your mask properly in order to avoid exposure to pathogens that may be on the outside of the mask. When you are ready to take off your mask, be sure to grab the straps that secure the mask to your head or face and release them without touching the front of the mask. You should have the mask fall directly into the waste bin or carry it by the straps to the waste bin. Ideally, you have a trash can outside of your house or apartment where you can dispose of the mask instead of bringing any pathogens clinging to the outside of it into your home. Wash your hands following proper hand hygiene once you’ve disposed of the mask and before touching your face.

Before putting on a new mask, be sure to wash your hands and avoid touching your face. Doing this will give you the best chance of avoiding exposure and contamination. Before you go outside, check to make sure your mask has created a tight seal on your face.

Other measures to take to protect yourself from coronavirus

First and foremost, wash your hands with soap and warm water regularly, as this is the best way to stop the spread of many pathogens, including coronavirus. Avoid touching your eyes, mouth, or nose with unwashed hands. – Dr. Patrick Kenney, DO, FACOI

“First and foremost, wash your hands with soap and warm water regularly, as this is the best way to stop the spread of many pathogens, including coronavirus,” Dr. Kenney advises, adding that you should “avoid touching your eyes, mouth, or nose with unwashed hands.” In order to ensure you’re practicing proper hand hygiene, make sure that you’re washing your hands with warm water and soap for at least 20 seconds after using the restroom, after coughing or sneezing, and before eating.

Dealing with sick people is a little more complicated. “Many respiratory viruses look similar,” Kenney explains, “and about 80% of the coronavirus cases are mild like most upper respiratory infections.” That means it can be hard to tell if your friend or neighbor has coronavirus or another respiratory disease that looks similar, especially since—as Kenney points out—we’re still in influenza (flu) season. But although you want to minimize person-to-person contact, you should still make sure they get the care they need. “Technology is a great way to facilitate care without exposure,” according to Kenney, and many hospitals have established text hotlines for people who think they are or know someone who’s sick with something that may be coronavirus.

If you fall ill, Kenney says you should stay home from work or school and seek medical attention and testing. “Most health care systems have a protocol for screening for potential exposures,” Kenney says, and this is a situation in which you should take advantage of technology-based medical care if it’s available to you. Finally, everyone should stay up-to-date on information about coronavirus since protocols for screening may change as well as areas in which health experts suggest that people wear face masks.

How did we get here?

In December 2019, local health officials in Wuhan, Hubei Province, China reported several cases of pneumonia among a group of people linked to a wholesale market in Wuhan. This coronavirus outbreak began in a highly-populated area, in the winter months, around the time for the celebration of Chinese New Year, Kenney explains. Anxiety about the outbreak kept getting higher as the virus spread beyond China.

To make things more complicated, people infected with coronavirus can be contagious before they show any symptoms, which Kenney explains makes it hard to contain. But “travel restrictions and mandated quarantines are in place to slow down the spread of the virus,” according to Kenney. He adds that “due to heightened awareness and travel restrictions, we have a better handle on limiting exposure.”

How does coronavirus spread?

It is currently believed that coronavirus is spread person-to-person by being in close contact with someone who’s infected because of airborne particles that contain the virus. “The virus is spread via respiratory droplets from coughing or sneezing,” Dr. Kenney explains. “Coronavirus tends to suspend in the air, much like other pathogens such as measles, chickenpox (varicella), and tuberculosis, so if a person is in close proximity to an infected person with respiratory symptoms, there is a high risk for exposure.”

But that’s doesn’t mean the only way to get the virus is to breathe these droplets. Viruses can get into your system through mucous membranes, which can be found in your mouth, nose, and eyes. So even if you block your mouth and nose from breathing air that contains the virus with a mask, the virus can still be transmitted if the virus is on your hands and you wipe your nose, rub your eyes, or eat without washing them.