[Fat Charlie]

Originally Posted by Piotrsko

It has to be just my problem: 1 micron filtration is transparent for something that is smaller than 1 micron. Covid is 1/178 micron, riding exhaled breath in a mist it's .5 micron max.

Actually, it looks to be .5 micron minimum.

Published data have suggested that sneezing may produce as many as 40 000 droplets between 0.5–12 μm in diameter that may be expelled at speeds up to 100 m/s, whereas coughing may produce up to 3000 droplet nuclei, about the same number as talking for five minutes. Despite the variety in size, large droplets comprise most of the total volume of expelled respiratory droplets. Further data on the behaviour of droplet dispersion in naturally generated aerosols are needed.