At the same time, if you are interested in particles around 1 micron size, you would not even think of getting a MERV 8 filter. Not that they would not filter anything at 1 micron. Just that the values are not of practical interest and MERV 8s don't get rated at that size 7/

To be fair, even your handkerchief will filter some 0.3 micron particles. That does not mean you will use it to protect against asbestos dust. Things have to be "fit for purpose" 8/