ASTM_E_1837_-_96_2014.pdf

Designation:E183796(Reapproved 2014)Standard Test Method toDetermine Efficacy of Disinfection Processes for ReusableMedical Devices(Simulated Use Test)1This standard is issued under the fixed designation E1837;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.INTRODUCTIONWhen special tests designed to register or validate a disinfection process currently are used,theprocedures,their statistical considerations(usually all negatives at a given time point),and thephysical problems of applying organisms to surfaces,such as sutures and unglazed porcelain carriers,may cause inaccurate and confusing results.Practical,in-use testing of reprocessing techniques andconditions are needed.Exaggerated conditions for testing can be achieved with the use of actualinstruments contaminated with high numbers of organisms.The addition of serum as an organic loador hard water minerals as an inorganic load can be made to enhance worst-case conditions.When theseelements are coupled with the processing,as actually performed,the result is a structured test that isa simulated-use procedure.This test method is designed to incorporate several elements ofreprocessing,including cleaning,rinsing,and disinfection(including optional treatment of the internalchannels of devices,such as endoscopes)with a terminal alcohol rinse rather than examining only theeffectiveness of the entire disinfection process.A simulated-use test to examine the effectiveness ofreprocessing procedures is valuable because several incidents of contamination of instruments in usehave been recorded with vegetative cells of bacteria,for example,Pseudomonas and the mycobacteria.When this procedure is performed with a representative mycobacterial culture,it is necessary to usea nonpathogenic strain such as Mycobacterium terrae(isolated from soil)that can be manipulated onan open bench.This strain is used in tuberculocidal testing in Europe,and published informationshows comparable resistance to antimicrobials as that displayed by human tuberculosis strains ofMycobacterium tuberculosis.This organism can be handled easily and grows faster than other teststrains,such as M.bovis(1-5).2Because contamination of the surfaces of instruments has occurred from rinsing with tap water,bacteria-free water should be used for all rinsing during reprocessing in this test procedure when awater rinse step is part of the reprocessing directions.1.Scope1.1 This test method is intended to describe a procedure fortesting the effectiveness of a disinfection process for reprocess-ing reusable medical devices when it is tested with a challengeof vegetative cells including mycobacteria.Disinfection nor-mally deals with testing activity against vegetative cells ofbacteria,viruses,and fungi.Since this test method is processoriented,the user may wish to examine a variety of testorganisms.1.2 This test method is designed to provide a reproducibleprocedure to verify the effectiveness of a previously validateddisinfectant or disinfection procedure for reusable medicalinstruments and devices.1.3 This test method is not meant to define the effectivenessof or validation of the particular disinfection process used or itskinetics,but rather,it is devised to confirm the effectiveness ofthe disinfection process by simulating use situations with aparticular test process using medical devices and instruments.Either manual or machine reprocessing can be tested.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.1,2014.Published December 2014.Originallyapproved in 1996.Last previous edition approved in 2007 as E1837 96(2007).DOI:10.1520/E1837-96R14.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 1.4 This test method is intended for use with reusablecleaned and previously sterilized or disinfected(high level)medical instruments and devices.Endoscopes are described inthis test method as a worst-case example for contamination andsampling.The selected sterilization or disinfection processes,or both,should have been validated previously,as well as theeffectiveness of rinsing for residual sterilant/disinfectant re-moval determined.1.5 An inoculum with high numbers of selected microor-ganisms is applied to both test and control,cleaned andsterilized,or disinfected medical instruments.Strains of mi-croorganisms with a recorded resistance to disinfectants areused to contaminate the instrument sites known or suspected tobe the most difficult to reproce