ASTM_E_3031_-_15.pdf

Designation:E303115Standard Test Method forDetermination of Antibacterial Activity on Ceramic Surfaces1This standard is issued under the fixed designation E3031;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 method is designed to quantitatively evaluate theantibacterial activity of glazed ceramic surfaces that have beenspecifically designed to contain an antibacterial treatment aspart of the glaze.This test method is meant to compare theefficacy of one ceramic surface to another ceramic surfaceusing the stated conditions and is not meant to be extrapolatedto other conditions.1.2 Knowledge of microbiological techniques is requiredfor this test.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:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1054 Test Methods for Evaluation of Inactivators of Anti-microbial AgentsE2180 Test Method for Determining the Activity of Incor-porated Antimicrobial Agent(s)In Polymeric or Hydro-phobic MaterialsE2756 Terminology Relating to Antimicrobial and AntiviralAgents2.2 ISO Standard:3ISO 22196 Measurement of Antibacterial Activity on Plas-tics and Other Non-porous Surfaces3.Terminology3.1 For definitions of terms used in this test method refer toTerminology E2756.4.Summary of Test Method4.1 This test method is used for evaluating the antibacterialeffect of antimicrobials incorporated into a ceramic glaze.Thisstandard does not seek to imitate all possible real worldscenarios but to provide a standardized method to comparemultiple antimicrobial technologies that can be incorporated orcoated on a ceramic surface.The inherent nature of the ceramictile allows for desiccation,therefore each ceramic specimen isequilibrated to the testing environment for 18-24 h.Once thetiles are equilibrated,bacteria are inoculated onto the surfacefollowed by a 24-h exposure time.Bacteria are recovered in aneutralizer broth and enumerated according to a validatedmethod.Log reductions are calculated for a treated versus anuntreated sample.5.Significance and Use5.1 Current solid surface test methodologies,such as theTest Method E2180 and ISO 22196,do not take into accountthe complexities associated with a ceramic surface.Thisincludes,but is not limited to,differing chemistries incorpo-rated into the glaze and desiccation due to water absorptionthrough the bisque body.Each point will be elaborated below:5.1.1 The glaze composition of ceramic tiles can varybetween manufacturers,lots,and product lines.Some glazechemistries such as tin,silver and copper can negatively impactthe testing conditions.Therefore,an untreated tile from thesame lot is not always suitable for comparison.The control tileproposed herein is capable of supporting growth over theindicated time frame and nutrient level(see Section 9).5.1.2 Desiccation is a common problem when testing tilesurfaces.This can be overcome by pre-hydrating the tile byplacing the specimen on a moistened wipe and allowing1This 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.15,2015.Published December 2015.DOI:10.1520/E3031152For 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 International Organization for Standardization(ISO),ISOCentral Secretariat,BIBC II,Chemin de Blandonnet 8,CP 401,1214 Vernier,Geneva,Switzerland,http:/www.iso.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 incubation for 18 to 24 h before beginning the test.Thisreduces the number of false positive results and more accu-rately measures the ability of the antimicrobial to inhibitgrowth.5.2 This test method utilizes a low inoculum load andrequires growth on the control substrate to demonstrate a validtesting environment.In addition,while some antimicrobialsdemonstrate activity against static cultures,others requiregrowth of the bacteria to maintain activity.A low inoculumlevel will allow for both