ASTM_F_838_-_15a.pdf

Designation:F83815aStandard Test Method forDetermining Bacterial Retention of Membrane FiltersUtilized for Liquid Filtration1This standard is issued under the fixed designation F838;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.NOTEFig.1 was editorially updated and the year date changed on Sept.30,2015.1.Scope1.1 This test method determines the bacterial retentioncharacteristics of membrane filters for liquid filtration usingBrevundimonas diminuta as the challenge organism.This testmethod may be employed to evaluate any membrane filtersystem used for liquid sterilization.1.2 This test method is not intended to be used in perfor-mance of product-and process-specific validation of thebacterial retention characteristics of membrane filters to beused in pharmaceutical or biopharmaceutical sterilizingfiltration,or both.Process-and product-specific bacterialretention validation should be carried out using the intendedproduct manufacturing process parameters and the productsolution or surrogate as the carrier fluid.1.3 The values stated in SI units are to be regarded asstandard.1.3.1 ExceptionThe inch-pound values given for units ofpressure are to be regarded as standard;SI unit conversions areshown in parentheses.1.4 This standard may involve hazardous materials,operations,and equipment.This standard does not purport toaddress all of the safety concerns,if any,associated with itsuse.It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent Water3.Terminology3.1 Definitions:3.1.1 log reduction valuethe logarithm to the base 10 ofthe ratio of the number of microorganisms in the challenge tothe number of organisms in the filtrate.4.Summary of Test Method4.1 After sterilization,the test filter is challenged with asuspension of B.diminuta(ATCC 191463)at a concentration of107organisms per cm2of effective filtration area(EFA)at amaximum differential pressure across the test filter of 30 psig(206 kPa)and a flow rate of 2 to 4 103LPM per cm2ofeffective filtration area.The entire filtrate is then filteredthrough an analytical membrane filer disc,which is subse-quently incubated on a solidified growth medium.Microorgan-isms that are not retained by the filter being tested will developinto visible colonies on the analysis membrane and can then beenumerated.5.Significance and Use5.1 This test method is designed to assess the retentivity ofa sterilizing filter under standard challenge conditions.5.1.1 A challenge of 107bacteria per cm2of effectivefiltration area is selected to provide a high degree of assurancethat the filter will be challenged uniformly across the mem-brane surface to assure it will quantitatively retain largenumbers of organisms.The model challenge organism,B.diminuta,is widely considered to be a small bacterium and isrecognized as an industry standard for qualifying sterilizingfilters.Other species may represent a worst-case test in termsof ability to penetrate a filter.This test does not provideassurance that filters can completely retain such bacteria.5.1.2 The analytical procedure utilized in this test methodprovides a method to assign a numerical value to the filtrationefficiency of the filter being evaluated under standard filtrationconditions.For the purpose of product sterility assurance,additional process-specific studies should be performed.1This test method is under the jurisdiction of ASTM Committee E55 onManufacture of Pharmaceutical and Biopharmaceutical Products and is the directresponsibility of Subcommittee E55.03 on General Pharmaceutical Standards.Current edition approved Sept.30,2015.Published October 2015.Originallyapproved in 1983.Last previous edition published in 2015 as F838 15.DOI:10.1520/F0838-15A.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American Type Culture Collection(ATCC),10801 UniversityBoulevard,Manassas,VA 20110,http:/www.atcc.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Apparatus6.1 Assemble the apparatus described below as in Fig.1:6.1.1 Stainless Steel Pressure Vessel,12-L capacity(orlarger),fitted with a 0 to 50-psi(0 to 350-kPa)pressure gauge.6.1.2 Air Regulator.6.1.3 47-mm142-mm Analysis Disc Filter Assemblies,twoor more,with hose or sanitary connections as applicable.6.1.4 Diaphragm-Protected 0 to 50-psi(0 to 350-kPa)Pressure Gauge,for upstream pressure reading.6