Protective face masks made from non-woven material and feature elastic earloops for comfort. Not made with natural rubber latex. Bacterial Filtration Efficiency (BFE) is the effectiveness of a material to filter bacteria of a specified particle size, 3.0 µm (micron) ± µm. This expressed as a percentage of a quantity that does not pass through the material Particle Filtration Efficiency (PFE) is the effectiveness of a material to filter aerosol particles in the size range 0.1 µm to 5.0µm. This is expressed as a percentage of a quantity that does not pass through the material.