This product is not intended for medical, healthcare, or laboratory personnel.
Making this for kids for whom breathability is a bit more important.
I then placed the elastic at the top and sewed down one side, across the bottom, then up the other side.
Schaffer , so it doesn't look pretty.
Steam looks promising, but cleaning method depends on the materials you use.
I found filter material that would filter 1 µm particles; I cut out part of a furnace filter.