I had a couple of the 'forensic' suits still in their bags up the loft. Never used, meant for digging on biologically dirty/hazardous sites ...recent graves, medieval hospital stuff.....and realising that I'd never use them now, I cut one up for masks. It's a non woven polyester stuff, even proof against nuclear particles says the blurb on the packet !...anyhow, the masks look just like the blue ones the hospitals are using but since mine aren't 'sterile' I wouldn't offer them to the NHS. I still have an arm and a leg though, and if you want some to make a liner for your leather mask, pm me and I'll put some in an envelope. I checked, and have washed mine and they're fine. I just used the same dilution of bleach in water that I use for the teatowels and the sink cloth. I reckon that'll kill anything noxious. So, if you made a couple of liners, that would let you wash and change as required.
Failing that, and for simplicity, coffee filters are supposed to be very good to use too, and they come a muted cafe latte colour so wouldn't look so weird against the colour of the leather as the blue might.
M
