According to the latest research from the National Institute of Standards and Technology (NIST), it is explained why face masks having exhalation valves are not effective for slowing the spread of COVID-19.
As we are at the end of the year 2020, it is clear that to prevent COVID-19 infection across the community; facemasks are highly recommended.
On the one hand, specialists are researching what materials in a face mask are generally protective. On the other hand, different researchers are recommending that we need to avoid wearing some particular sorts of masks.
It’s been months that people are using face masks with exhaust valves, but recently a well-known engineer Matthew Staymates at NIST, presented how these sorts of face masks can project small droplets into the air even after wearing them.
“I don’t wear a mask to protect myself,” says Staymates. “I wear it to protect my neighbor because I might be asymptomatic and spread the virus without even knowing it. But if I’m wearing a mask with a valve on it, I’m not helping either.
According to Staymates latest experiments published in the famous journal called Physics of Fluid, he beautifully explained the two most convincing visualization techniques demonstrating precisely these face masks that allow exhaled air to disperse into the environment.
He stressed his mere focus on conveying this message through two videos that these masks are totally useless at controlling the droplets coming from our mouth during this pandemic. “If we compare the video’s side by side, the difference is quite visible,” he notes. “These videos show how the valves allow air to leave the mask without filtering it, which defeats the purpose of the mask.”
Since it is much easier to breathe through these N95 masks, people prefer wearing them instead of a regular surgical face-covering mask. Maybe this can be counted as the only reason why these masks have gained more popularity worldwide. Originally these masks were designed for the workers on the construction site to avoid dust or specifically for hospital staff to keep a distance from infected patients.
The videos linked here do not demonstrate any movement of the small particles. However, the airflow visualizations offer easy to understand the depiction of how small droplets are being escaped from these so-called secure masks.
His only reason for such an experiment was to guide people about choosing the right mask to avoid the spread of this viral disease.
He concluded by saying, “I hope that this work will help inform a large audience that valves on a mask are not helpful as we fight this global pandemic together.”