Requirements

Setting these requirements, we can then evaluate the best design.

Can be 3D printed readily
Has a replaceable filter
Filter holder is modular - and different geometries of filter holder can be used to accommodate different filter material thicknesses and geometries
Mask itself is cleanable
Allows for use of any filter material
Has a gasket around entire perimeter that allows air only through the intended filter material

Deployment:

Likely candidate is plastic body (PETg or washable material) with elastomer (TPU) gasket
Can be deployed to 5000 3D printers at the OSMS site

Advanced Features

Mechanisms for cleaning:
1. For example, extraction of filter and placement in an ozonation chamber?

UV - is shaded by material, so can apply only to surface disinfection, not deep within a material
Ozone - as a gas, it has a chance to permeate a material for thorough cleaning
Alcohol, bleach - can give off powerful vapors to kill germs and permeate 3D prints, but also don't want to kill humans if vapors persist
- don't think doctors would use it for equipment and wounds if it did
- source that this would be bad? Doctors use hydroperoxide and alcohol sanitizers, the vapour goes away quite quickly from surface areas.

Based on these 3 considerations - ozone appears to be the optimal cleaner? Worthwhile to star Open Source Ozone Generator.

- Ozone is not good to breath in either, especially bad for the lungs and airways as it reacts, irritates and damages the inner membranes. Is there a link about ozone against viruses? Read from a virologist who recommended 70% alcohol or 10% bleach for at least 15 minutes.