ASTM_E_2783_-_11.pdf

Designation:E278311Standard Test Method forAssessment of Antimicrobial Activity for Water MiscibleCompounds Using a Time-Kill Procedure1This standard is issued under the fixed designation E2783;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 measures the changes of a populationof aerobic and anaerobic microorganisms within a specificsampling time when tested against antimicrobial test materialsin vitro.The organisms used are standardized as to growthrequirements and inoculum preparation and must grow underthe conditions of the test.The primary purpose of this testmethod is to provide a set of standardized conditions and testorganisms to facilitate comparative assessments of antimicro-bial materials miscible in aqueous systems.1.2 This test method allows the option of using a test samplesize of 10 mL or 100 mL.1.3 Knowledge of microbiological techniques is requiredfor this procedure.1.4 Aseptic technique should be practiced at all times.1.5 In this test method,SI units are used for all applications,except for distance in which case inches are used and SI unitsfollow in parentheses.1.6 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 MethodE1054 Test Methods for Evaluation of Inactivators of Anti-microbial Agents3.Terminology3.1 Definitions:3.1.1 antimicrobial,ndescribes an agent that kills orinactivates microorganisms or suppresses their growth orreproduction.3.1.2 drug,narticles intended for use in the diagnosis,cure,mitigation,treatment,or prevention of disease in man orother animals.Drugs are intended to affect the structure or anyfunction of the body of man or other animals.3.1.3 initial microbial population,nbacterial count(CFU/mL)in the final volume of test material.Also known as initialbacterial population,numbers control or control.3.1.4 inoculum,nthe viable microorganisms used to con-taminate a sample,device or surface,often expressed as tonumber and type.3.1.5 microbiocide,na physical or chemical agent thatkills microorganisms.3.1.6 neutralization,nthe process for inactivating orquenching the activity of a microbiocide.Often achievedthrough chemical or physical means(for example,filtration ordilution).3.1.7 room temperature,ntemperature in the range of 20to 30C(68 to 85F).3.1.8 test material,na formulation which incorporatesantimicrobial ingredient(s).Also known as test formulation.3.1.9 total test volume,nthe volume of test material plusthe volume of inoculum suspension.4.Summary of Test Method4.1 A dilution/aliquot of the test material is brought intocontact with a known population of test organisms for specifiedperiods of time,at a specified temperature.The activity of thetest material is quenched at specified sampling intervals(example 15,30,and 60 s,or any range covering severalminutes or hours)with an appropriate neutralizing technique.The test material is neutralized at the sampling time and thesurviving microorganisms enumerated.The percent and log10reduction,from an initial microbial population is calculated.1This test method is under the jurisdiction of ASTM Committee E35 onPesticides,Antimicrobials,and Alternative Control Agents and is the directresponsibility of Subcommittee E35.15 on Antimicrobial Agents.Current edition approved Oct.1,2011.Published October 2011.Originallyapproved in 2010.Last previous edition approved in 2010 as E2783 10.DOI:10.1520/E278311.2For 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 5.Significance and Use5.1 This procedure may be used to assess the in vitroreduction of a microbial population of test organisms afterexposure to a test material.6.Apparatus6.1 Adjustable or Fixed Volume PipetCapable of dispens-ing 0.1 mL and 1.0 mL.6.2 Anaerobic Jar or IncubatorAny incubator or appara-tus in an incubator that creates an environment having a levelof oxygen that does not support the growth of oxygen-requiringmicroorganisms.Required only for organisms that need ananaerobic environment to grow.6.3 BalanceAny suitable laboratory balance with a mini-mum readability of 0.01 g.6.4 Beakers and Magnetic Stir BarsFor 100 mL samplesize.A 250 mL beaker containing a 51