A challenge testing configuration for an in-situ pharmaceutical installation of an ePTFE filtering media, comprising: a pleated filtering media having a plurality of pleats, wherein said pleated filtering media is positioned within an air stream of an air handling unit in an aseptic pharmaceutical airstream handling system, said filtering media including an upstream support scrim and a downstream support scrim and an ePTFE membrane interposed between said upstream support scrim and said downstream support scrim; wherein said upstream support scrim and said downstream support scrim are a bi-component material and said ePTFE membrane is laminated therebetween; a poly-alpha olefin separator (51, 56) between each of said plurality of pleats of said pleated filtering media; an upstream low volume aerosol generator combined with an aerosol diluter providing less than 0.3 μg aerosol/L air down to 0.01 μg aerosol/L air and below for ultra-low aerosol concentrations into said air stream of said air handling unit; an upstream scanner for detection of the aerosol concentrations for ultra-low volumes at said upstream support scrim of said filtering media; a downstream scanner with a scanning probe inserted into said air handling unit downstream of said pleated filtering media and facing said downstream support scrim, said scanning probe inserted through an access port in said air handling unit of said pharmaceutical airstream handling system for detection of the aerosol concentrations for ultra-low volumes passing through said downstream support scrim of down to 0.01 percent of the aerosol concentrations for ultra-low volumes detected at said upstream scanner. a pleated filtering media having a plurality of pleats, wherein said pleated filtering media is positioned within an air stream of an air handling unit in an aseptic pharmaceutical airstream handling system, said filtering media including an upstream support scrim and a downstream support scrim and an ePTFE membrane interposed between said upstream support scrim and said downstream support scrim; wherein said upstream support scrim and said downstream support scrim are a bi-component material and said ePTFE membrane is laminated therebetween; a poly-alpha olefin separator (51, 56) between each of said plurality of pleats of said pleated filtering media; an upstream low volume aerosol generator combined with an aerosol diluter providing less than 0.3 μg aerosol/L air down to 0.01 μg aerosol/L air and below for ultra-low aerosol concentrations into said air stream of said air handling unit; an upstream scanner for detection of the aerosol concentrations for ultra-low volumes at said upstream support scrim of said filtering media; a downstream scanner with a scanning probe inserted into said air handling unit downstream of said pleated filtering media and facing said downstream support scrim, said scanning probe inserted through an access port in said air handling unit of said pharmaceutical airstream handling system for detection of the aerosol concentrations for ultra-low volumes passing through said downstream support scrim of down to 0.01 percent of the aerosol concentrations for ultra-low volumes detected at said upstream scanner.