The Truth About Masks with Valves

Cloth, fashion, surgical—it’s easy to feel overwhelmed by the number of mask choices available in the COVID-19 pandemic and confused about which kind is best for you. You may see masks with plastic or rubber valves on them, known as exhalation valves. A common perception is that they add an extra level of protection to masks making them a worthy investment.

However, medical experts say otherwise.

Read on to learn about scientific facts and perspectives on masks with exhalation valves so you can make an informed decision on how to protect yourself and others during this pandemic.


What are exhalation valves?

 First, what is an exhalation valve? As the CDC says, it’s a component of a respirator—a personal protective device that is worn on the face or head and covers the nose and mouth. One category of respirators is the N-95 filtering facepiece respirator (FFR), which removes particles from the air that are breathed through it.  There are N-95 masks with and without exhalation valves, and there are also cloth and disposable masks that have exhalation valves at the front. The valves intend to make it easier to breathe by reducing exhalation resistance. Specifically, the valve reduces excessive dampness and warmth in the mask from exhaled breath. It works by opening to release the exhaled air and closes during inhalation so that the inhaled air comes through the filter.

 According to Oxford Academic, exhalation valves are made up of three main components: a valve membrane, a seat, and a cover. The valve membranes are usually made of natural or silicon rubber or neoprene. The seats have a base with a cross bracket and the valve membrane is attached to the seat.


How do masks with valves work?

The valve sits against the base to block the valve hole during inhalation and lifts from the base with the positive pressure established during exhalation. The air you exhale has no filtration, so unfortunately there’s nothing to stop an infected person from breathing contagious viral particles into the air.


Exhalation valves don’t help stop coronavirus

 The pandemic has caused consumers to “panic buy” masks like the FFR without knowing their effectiveness. Actually, the CDC and other scientific and medical organizations have urged people to avoid masks with exhalation valves. The point of the CDC’s current guidelines for masking is to prevent infected individuals from spreading the highly transmissible coronavirus to others. Valve masks fall short because they only filter air that’s breathed in, not the air that’s breathed out. The exhaled air passes unfiltered into the environment, which means coronavirus droplets can be released with the exhalation.

 Valve masks defeat the purpose of wearing masks during this pandemic: to protect others around you. As Dr. William Schaffner, an MD and professor at Vanderbilt University Medical Center, said to ABC News, “We want to protect you from me. And so, this valved N95 [mask] really doesn’t function appropriately in this COVID-environment, either in the healthcare setting or in the community.”

 Wait a minute—healthcare workers shouldn’t wear them either?

The CDC recommends that respirators with exhalation valves shouldn’t be used in situations where a sterile field must be maintained; for example, in hospitals during an invasive procedure in an operating or procedure room. The valve causes unfiltered air to be exhaled into the sterile field. The masks may actually propel germs further, endangering patients and others. Healthcare workers should choose N-95 masks without the valve, and regular citizens would be best served with a cloth or surgical mask.


Valve masks then and now

It’s interesting to note that N-95 valve masks weren’t even intended for healthcare purposes originally. Fast Company recently covered the origin of N-95 masks and found out that they initially were supposed to be used in factories and coal mines. They were industrial respirators that were supposed to filter dust from the air that would be harmful to breathe in. However, wearing one would be very uncomfortable in an industrial setting because it traps the heat and vapor from your mouth. Valves on the masks helped keep the wearer cooler and more comfortable during long shifts.

If someone with a cold or flu wore them, wearing them in a solitary coal mine would have fewer consequences than wearing them in public. In the 1990s, doctors wanted a new airborne protection method against AIDS and tuberculosis, so they bought into N95 masks and created standards for them. At that time, the medical community mandated that the masks didn’t have valves so healthcare workers wouldn’t get people around them sick. It’s a guideline we should follow today.

The avoidance of masks with exhalation valves is an issue that needs more attention right now. The National Institute of Health calls for increasing awareness to the public, saying, “The risks related to the presence of an exhalation valve are not intuitive for the general population and should not be silenced by institutions and governments.”

California’s Bay Area was one of the early states to ban valve masks on April 17. Violations can be counted as a misdemeanor under the California Health and Safety Code and can result in a fine up to $1,000, imprisonment up to 90 days, or both. Other states are likely to follow suit with implementing their own bans in upcoming months.

The CDC urges that the general public wear cloth masks, but you should invest in ones with extra protection and without valves. Well-designed masks will have a high filtration efficiency but still have methods to control heat and humidity such as moisture-wicking qualities. These features mean that there is no need for an exhalation valve to reduce dampness and warmth. Remember, you should choose masks that are not only comfortable for you but also keep you from spreading germs to others. 


In this pandemic, wearing masks with exhalation valves can facilitate the spreading of coronavirus, not stop it. Therefore, you should stay away from them and urge others around you to do the same. Soon enough, more states will be adopting anti-valve mask regulations, so keep checking with your state’s local health departments and those of any states you’re planning to visit.  

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