With the outbreak of the coronavirus, many people are wondering if masks capture coronavirus particles. It’s a lot to ask billions of people around the world to become mask experts overnight.
How Big Are Coronavirus Particles?
First things first: we need to know how big the coronavirus is. Scientists have already used electron microscopes to measure how big the corona virus is. Coronavirus particles (fancy scientific name “virions”) are spheres with diameters of approximately 0.125 microns (125 nm). The smallest particles are 0.06 microns, and the largest are 0.14 microns.
The scientific test:
Researchers from the University of Edinburgh tested different common masks by running a diesel generator (to mimic car exhaust) and piping the exhaust through the masks. They used a particle counter to see how many particles made it through the mask. Here’s my super scientific rendering of the setup:
One important detail: the particle counter they used measured particles as small as 0.007 microns. That’s over 10 times smaller than the coronavirus particle diameter. We’re talking about truly tiny particles here!
They tested a whole range of masks, and here’s what they found:
3M industrial filters were able to capture over 95% of particles down to 0.007 micron. Given that news outlets have claimed surgical masks can’t capture nanoparticles, it’s particularly surprising that the surgical mask was able to capture 80% of the tiny particles.
OK, but that was car exhaust. Maybe there’s something different about virus particles? In another study, researchers shot actual virus particles at N95 masks. The masks captured over 95% of virus particles.