ASTM_F_1608_-_16.pdf

Designation:F160816Standard Test Method forMicrobial Ranking of Porous Packaging Materials(ExposureChamber Method)1This standard is issued under the fixed designation F1608;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method is used to determine the passage ofairborne bacteria through porous materials intended for use inpackaging sterile medical devices.This test method is designedto test materials under conditions that result in the detectablepassage of bacterial spores through the test material.1.1.1 A round-robin study was conducted with eleven labo-ratories participating.Each laboratory tested duplicate samplesof six commercially available porous materials to determinethe Log Reduction Value(LRV)(see calculation in Section 12).Materials tested under the standard conditions described in thistest method returned average values that range from LRV 1.7 to4.3.1.1.2 Results of this round-robin study indicate that cautionshould be used when comparing test data and rankingmaterials,especially when a small number of sample replicatesare used.In addition,further collaborative work(such asdescribed in Practice E691)should be conducted before thistest method would be considered adequate for purposes ofsetting performance standards.1.2 This test method requires manipulation of microorgan-isms and should be performed only by trained personnel.TheU.S.Department of Health and Human Services publicationBiosafety in Microbiological and Biomedical Laboratories(CDC/NIH-HHS Publication No.84-8395)should be con-sulted for guidance.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:3.1.1 porous packaging material,na material used inmedical packaging which is intended to provide an environ-mental and biological barrier,while allowing sufficient air flowto be used in gaseous sterilization methods(for example,ethylene oxide,steam,gas plasma).4.Summary of Test Method4.1 Samples of porous materials are subjected to an aerosolof Bacillus atrophaeus spores within an exposure chamber.Spores which pass through the porous sample are collected onmembrane filters and enumerated.The LRV is calculated bycomparing the logarithm of the number of spores passingthrough the porous material with the logarithm of the microbialchallenge.4.2 Standard Set of ConditionsThis test method specifiesa standard set of conditions for conducting the exposurechamber test method.Astandard set of conditions is required toenable evaluation of materials between laboratories.The con-ditions stated in this test method were chosen for severalreasons.First,it is difficult to maintain an aerosol of sporesover long periods of time.(Also,if the spore challenge time islong,the cost of the test increases).Second,to determine thedifferences between materials,it is necessary to test thematerials under conditions which allow passage of bacterialspores.If a material does not allow any passage of spores,allthat can be stated is that it has better resistance to penetrationthan the severity of the challenge conditions.Third,it isnecessary to have a large spore challenge level to be able todetect the passage of spores through the entire range of1This test method is under the jurisdiction ofASTM Committee F02 on FlexibleBarrier Packaging and is the direct responsibility of Subcommittee F02.15 onChemical/Safety Properties.Current edition approved May 1,2016.Published June 2016.Originallyapproved in 1995.Last previous edition approved in 2009 as F1608 00(2009).DOI:10.1520/F1608-16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 commercially available porous packaging materials.The stan-dard conditions stated in this test method are based upon thesefactors.(Additional information may be found in the Refer-ences section).However,since many factors influence thedetermination of an appropriate porous material(outlined in5.1.1 5.1.4),each user may modify these conditions(that is,bacterial challenge,time,flow rate)after fir