IFJ_03-2020_PPE_3MN95 Ken Norberg May 27, 2020 4 Views N95 facemasks have a 95 percent efficiency at filtering out contaminants down to a size of 0.3 microns. Photo courtesy of 3M N95 facemasks have a 95 percent efficiency at filtering out contaminants down to a size of 0.3 microns. Photo courtesy of 3M