Electrospun nylon 6 fiber mats were deposited on woven 50/50 nylon/cotton fabric with the motive of making them into protective material against submicron-level aerosol chemical and biological threats. Polymer solution concentration, electrospinning voltage, and deposition areal densities v,,ere varied to establish the relationships of processing-structure-filtration efficiency of electrospun fiber mats. A high barrier efficiency of greater than 99.5%, was achieved on electrospun fiber mats without sacrificing air permeability and pressure drop. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 2181-2187, 2010