Results of N-95 Mask with Valves Simulation
In their next setup, the researchers visualized how the vapor will travel if the mannequin is wearing a regular N-95 mask with valves.
Immediately after coughing, some of the droplets escaped through the gaps (top of the mask and bridge of the nose). But what’s alarming is that the majority of the vapor escaped through the valve. Initially, the droplets deflected downward, but soon after, they spread over a wide area.
Now, to compare, the researchers then made the mannequin wear a regular N-95 mask without exhalation valves. The visualization test showed that after coughing, some of the droplets escaped through the gaps as well. However, the researchers stated that “the extent of exposure will be lower compared to that for either face shields or masks with valves.”
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.