N95 masks just need to filter 95% to get that certification. They don’t filter as much as FFP3 masks but only as much as FFP2 masks. They aren’t equipment that keeps out all the smaller particles.
Davis et al 2013 suggests ~90% filtration for surgical masks. I read somewhere in the literature that in cases where studies found similar effects for protection by surgical masks and N95 masks it’s likely because the N95 masks didn’t fit correctly.
Davies et al is encouraging as regards the benefits of surgical masks. Still, letting 10% in is a lot worse than letting 5% in, and the fact that the Wikipedia page about N95 masks says “Collection efficiency of surgical mask filters can range from less than 10% to nearly 90% for different manufacturers’ masks when measured using the test parameters for NIOSH certification” suggests that maybe Davies et al got lucky in which surgical masks they tested.
N95 masks just need to filter 95% to get that certification. They don’t filter as much as FFP3 masks but only as much as FFP2 masks. They aren’t equipment that keeps out all the smaller particles.
Davis et al 2013 suggests ~90% filtration for surgical masks. I read somewhere in the literature that in cases where studies found similar effects for protection by surgical masks and N95 masks it’s likely because the N95 masks didn’t fit correctly.
Davies et al is encouraging as regards the benefits of surgical masks. Still, letting 10% in is a lot worse than letting 5% in, and the fact that the Wikipedia page about N95 masks says “Collection efficiency of surgical mask filters can range from less than 10% to nearly 90% for different manufacturers’ masks when measured using the test parameters for NIOSH certification” suggests that maybe Davies et al got lucky in which surgical masks they tested.