Even the CDC recommends that we do not use masks with valves because, while it can protect the wearer, it does a poor job of protecting the people around the wearer. This is because the one-way valve releases the exhaled air, unfiltered. This can allow exhaled respiratory droplets to spread to others.
Results of Surgical Masks Simulation
After their simulation with plastic face shields for COVID-19 and mask with valves, the researchers proceeded in testing commercially available surgical masks.
In this setup, they used 2 different brands of plain surgical face masks. Both of which, according to the manufacturers, were “not recommended for medical use.”
As these masks are widely available to the public, researchers wanted to know the extent by which they can reduce COVID-19 spread.
Brand A seems to be highly effective in stopping the “forward progression” of the vapor. There was leakage from the gaps, but it was “not excessive.” In fact, the researchers noted that “it is comparable qualitatively to leakage from the regular N95-rated mask.”
Brand B, on the other hand, didn’t fare too well. Not only did the vapor escape through the gaps, but there was also significant leakage through the material itself.
The conclusion is that while many masks appear to be superficially similar, there are still underlying differences. And these differences could affect their overall quality. The findings of this study hopefully help to enlighten the public about the wearing of masks and plastic face shields for COVID-19.
The Study’s Conclusion
After assessing the effectiveness of plastic face shields for COVID-19 and masks with valves, researchers came to the conclusion that face shields or masks with valves may not be as effective as a regular face mask when it comes to reducing the spread of aerosolized droplets.