3Ply Surgical Face Mask : The design of the surgical masks depends on the mode; usually, the masks are three–ply (three layers). This three–ply material is made up of a melt-blown polymer, most commonly polypropylene, placed between non-woven fabric. … The masks are secured to the head with ear loops, head ties, or elastic straps. Mask should be secured with an ear loop to be placed behind the ears. > 99% Bacterial Filtration Efficiency (BFE) at 5 micron capacity; >95% Bacteria Filtration Efficiency (BFE) at 3 micron capacity.