ASTM_D_4196_-_05_2011.pdf

Designation:D419605(Reapproved 2011)Standard Test Method forConfirming the Sterility of Membrane Filters1This standard is issued under the fixed designation D4196;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 describes a test to confirm the sterilityof either manufacturer presterilized or user-sterilized analyticalmembrane filters.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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:2D1129 Terminology Relating to WaterD1193 Specification for Reagent Water2.2 Other Standard:The United States Pharmacopeia,Current Edition3(Sec-tions on Sterilization and Sterility Testing)3.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology D1129.4.Summary of Test Method4.1 The membrane filters are immersed in sterile culturemedia and incubated at temperatures that are suitable forgrowth of viable bacteria,fungi,and yeasts.Growth oforganisms is evidence that the filter has failed the test.5.Significance and Use5.1 This test method may be employed to check the sterilityof commercially procured sterile membrane filters.The testalso confirms that sterilized filters have not been contaminated.Additionally,this test may be used to monitor the efficacy ofin-house sterilization procedures.Filter packages that haveobvious packaging defects should not be tested because steril-ity may have been compromised.6.Reagents and Materials6.1 Purity of Water Unless otherwise indicated,referenceto water shall be understood to mean Type II reagent gradewater in accordance with Specification D1193.6.2 MediaUse commercially available dehydrated media.Dissolve and sterilize by autoclaving,in accordance with themanufacturers directions.6.2.1 Fluid Thioglycollate Medium(Note)Dispense40-mL aliquots into suitable-sized vessels with screw-capclosure,providing a ratio of surface area to depth of medium sothat no more than the upper half of the medium has initiallyundergone a color change indicative of oxygen uptake.Whenready for use,not more than the upper one tenth of the mediumshould be pink.The medium may be restored once by heatingin free-flowing steam until the pink color disappears.The pH ofthe medium,after autoclaving,should be 7.1 6 0.2.NOTE1If stored at 2 to 5C in sealed containers,the media may beused for 1 year provided they are tested for the growth-promotingproperties every 3 months.6.2.2 Soybean-Casein Digest Medium(Note)Dispense40-mL aliquots into suitable vessels with screw-cap closure.The pH after autoclaving should be 7.3 6 0.2.6.2.3 Perform a sterility test on each lot of autoclavedmedium by incubating ten representative containers of eachmedium,for not less than 10 days,at the specified testtemperature.6.2.4 Perform a growth-promotion test,as described below,on each lot of autoclaved medium.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.08 on Membranes and IonExchange Materials.Current edition approved May 1,2011.Published June 2011.Originallyapproved in 1982.Last previous edition approved in 2005 as D4196 05.DOI:10.1520/D4196-05R11.2For 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.3Mack Publishing Co.,Easton,PA 18042.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2.4.1 Inoculate duplicate test containers of each mediumseparately with less than 100 of each of the below listedmicroorganisms.Incubate 7 days at the temperatures listedbelow:MediumTest OrganismsATemperature,CFluid thioglycollateBacillus subtilis(ATCC 6633)B30 to 35Candida Albicans(ATCC 10231)30 to 35Soybean-caseinBacillus subtilis(ATCC 6633)B20 to 25Candida albicans(ATCC 10231)20 to 25AAvailable from the American Type Culture Collection,12301 Parkview Drive,Rockville,MD 20852.BIf a non-spore-forming organism is desired,use Micrococcus Luteus(ATCC9341).6.2.4.2 The media are satisfactory if growth of the micro-organisms is apparent within 7 days.The growth-promotiontest may be performed simultaneously with the sterility test ofthe media.However,the media sterility test will be consideredinvalid if the growth promotion test shows no growth.7.Sterility Test