An interesting find

Some time ago, when all of this COVID-19 business began and masks were in short supply, I wondered about the possibility of making a mask that used extremely simply pieces of material as a filter; for example, the discs of filter paper commonly used in laboratories. I was wondering about it in the general sense, not just as regards this particular pandemic. Well, one thing led to another, and the idea went on the back burner. Today, looking around at various masks, I came across a "flu pandemic kit" by Sundstrom Safety (a Swedish PPE company). Their kit contains a mask, a P100 filter cartridge, and a large number of "pre-filters" (just simple paper discs). They claim that the pre-filters can just be changed once a week and the main filter can be disinfected with a 5-minute soak in rubbing alcohol, so that the kit (and presumably at least a few gallons of rubbing alcohol) can last one person 18 months of daily use at a 99.97% effective filtration rate.

Also interesting to me is the filter connection. The filters are squat cylinders, or thick discs, whichever you like; they simply pop into a rubber ring the same diameter as they are. They have the inhalation valve built in (so it gets replaced whenever you replace the filters). Also, since the connection is the full diameter of the filter, you're not putting up with the flow restriction of a narrower connection (some gas masks have connections as small as one inch in diameter). For someone sitting at a desk or whatever, it wouldn't make a lot of difference. But for someone trying to have a brisk walk, do exercise, or perform manual labor, that extra flow could be very useful. I hope to order a few kits once they again become available, and send them to family members. For some reason, I'm about the only person in my immediate family with no respiratory problems.

For myself, I ordered a Moldex 8000-series respirator, which accepts two such plug-in canisters. I also ordered a few filter pads and the necessary retaining rings for them. Hopefully, they will give better performance than the neoprene exercise mask I've been using while exercising. We'll see.