[blam]

Just as a reference for the micron challenged, a micron is real small, for example a normal human (Caucasian ) hair is about 100 microns in diameter.

When I retired from chip-making, we were routinely printing patterns in the .25 micron range.

[Nebullis]

Masks are not really made for virus protection but the coronavirus just happens to be relatively large for a virus so the N95 can be useful. Masks could be made to be more specifically effective for filtrating coronaviruses, i.e. chemicals damaging to the coat proteins could be embedded within the filter material.

[Domestic Church]

"When I retired from chip-making, we were routinely printing patterns in the .25 micron range."

We need to pull you out of retirement.