(08-12-2020, 11:49 AM)36654 Wrote: There's a whole world of devoted fans to certain Kirby HEPA vacuum bags for masks.Perhaps an inappropriate comment..., but, with all due respect, didn't I tell you guys to avoid PP (personal protection) envy?
I think a MERV13 filter approximates 95% BFE
And, from my days as an ER doc, I'll simply remind you that mixing PP and a vacuum cleaner never ends well.
(Right. Only jokes about farts are more universal.)
By the way, if you add filter material, it has to fill the whole mask and then the mask has to fit well.... Sound like a lot of work. (Or, it sounds like a project an old bike mechanic and machinist would find relaxing.)
Also - BFE is tested for 3.0 micron particles and germs. N95 is tested for smaller particles - 0.3 micron. As noted, most cloth masks without filters will meet 95% bacterial filtration efficiency without adding a filter. If you're going to add a full-mask filter, aim for N95 or better....
If you want to save money and time worrying about whether you have statistically sufficient protection, simply order a bunch of Chinese KN95 masks from Amazon, and you'll have a mask that when used with a little common sense, will keep your risk for sucking up some viral particles acceptably low. If you want to keep your risk at zero..., well..., good luck. We'll see you in a few years.)
"A good man always knows his limitations...."