The role of fit testing N95/FFP2/FFP3 masks: a narrative ...
Sep 15, 2020·N95/FFP2 masks are essentially high‐filtration, negative‐pressure respiratory masks designed to filter at least 94–95%, while N99/FFP3 masks are designed to filter at least 99% of aerosol containing particles (sodium chloride) as small as 0.3–0.6 µm in diameter, with N100 masks having an even higher filtration capacity .