So, which type of mask is best to prevent the spread of COVID-19? Last week the Cheyenne River Sioux Tribe delivered packets of KN-95 masks free to local businesses. The Topic asked Marcia O’Leary, director of Missouri Breaks Industries, part of the team that assists the CRST on the pandemic, whether those are the best ones. Do all the 95 masks filter what’s going in and what’s going out as we breathe? Here’s what she said:
Yes, they are the best. The KN-95 masks (Chinese standard) and the N-95 masks (US standard) filter both in and out. The N-95 is the best - it filters out 95% - thus the name. The KN-95 is an offshoot of the N-95 and is very good.
But these high grade masks are typically reserved for health care workers who are at a much higher level or risk. Although all masks are not created equal something is better than nothing. Layers and fit are important elements in a surgical or homemade mask. The better the fit the better the filtration is both in and out.
The cloth masks are probably the least effective and the surgical (of which there are a variety) are in the middle. The issue to consider when deciding on the mask that will be needed is the amount of virulence and the amount of time that one will potentially be exposed. Other factors to consider include existing ventilation systems, inability to distance from others (such as if you are a clinician) and risk factors for individuals wearing the masks.