With a standard N95 or N100 filter, you can use them till they are hard to breath through. For a prefilter, well I typically don’t use them as the bayonet filters are disposable. It wouldn’t do much good anyway unless it is N95 or better. I know of hospitals making their own N95 masks using HEPA furnace filters.
https://www.unitypoint.org/filesimages/COVID-19/UnityPointHealth-OlsonMask-Instructions.pdf
Using furnace filters MAY help.
For length of use... Well I once work some pink N95 filters for 90 days with out changing out. They were for crystalline silica, and not a “hot” zone so I would pull the filters before cleaning the mask, inspect the seals, and then reassemble. DO NOT wash with the filters on. Bleach destroys the filter material. In a Cl gas cartridge, you have layers to stop the chlorine, then the particulate.
In a “hot” zone, the outer layer of the filter will be the hottest. I have reused cartridges in known hot zones, but they had to be pulled while wearing PPE, and reattached while wearing the same. If you can, since this is a biologic, let the cartridges sit some place till the bug is assumed dead if you have to reuse. Not sure how long, but assume it is the same length of time as exposed fabric. You can do a quick clean with an alcohol wipe, but I would not use to much.
Again, we typically never tried to reuse the cartridges from a hot zone. Just threw them away as part of the decon process. Looking back, that was a hell of a luxury
OK, Gotcha and thanks!
I got to digging around and it appears that I have 3 sets for an older 3M 7200 and 3 sets for the North.
If I resupply every 10 - 12 days they should last to at least the end of the summer.
Perhaps by then cartridges will be available to non-First Responders.
I do not go into stores at all, just Sam’s early opening days and get what I can.
I am in the middle of Dallas and the DFW area is at 1,617 confirmed and 29 dead as of this afternoon.
According to the “experts” we are not going to peak until about May 2-3rd.
Gonna be a lot of `rona floating around and my next trip out I am tacking in my GI issue goggles with the vents taped off.
I start my decon as soon as I have everything loaded into the back of the truck.
91% alcohol soaked paper towels in a zip-lock sticking out of my shirt pocket is easy for cleaning my hands and forearms before I get the keys out of my pocket, I leave the respirator on for the drive home.
Unload truck onto picnic table by back door and spray down everything with 70% alcohol and will soon switch to the dilute bleach solution mixed before I leave for the Sam’s.
Shoes and shirt are dropped at the back door, respirator just inside, clothes off and directly into the washer and walk straight to the shower, dress and bring in the supplies.
I just can’t fathom at least not fighting back against this with a few inconvenient but simple procedures.
Thanks again.
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