1、Designation: E 2314 03 (Reapproved 2008)Standard Test Method forDetermination of Effectiveness of Cleaning Processes forReusable Medical Instruments Using a MicrobiologicMethod (Simulated Use Test)1This standard is issued under the fixed designation E 2314; the number immediately following the desig
2、nation 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.INTRODUCTIONCleaning is acknowledged as the
3、 critical first step in the reprocessing of reusable medicalinstruments. A test method to examine the efficacy and reproducibility of cleaning procedures wouldbe valuable in optimizing decontamination of medical instruments, as well as increasing the marginof safety of subsequent disinfection and st
4、erilization procedures. This test method is a means ofdetermining the efficacy of the instrument manufacturers cleaning instructions. In this simulated usetest cleaning steps are performed with the instruments in a controlled laboratory environment. Withinthis environment, various parameters may be
5、exaggerated to create worst-case conditions for the test.Among these are the amount or type of organic soil or microorganisms contaminating the instruments.The test method was developed primarily for large medical instruments or instruments with internalchannels or recesses (for example, flexible en
6、doscopes) but may be used for any resuable medicalinstruments. It employs both direct inoculation and sampling methods for external surfaces andindirect inoculation and sampling methods for less accessible internal channels.Cleaning is defined as the removal of foreign materials, most often mixtures
7、 of organic soil (forexample, protein) and microorganisms, from medical instruments. Bacterial endospores are thepreferred microorganisms in this simulated test because they would be more resistant to the potentialmicrobiocidal effects of the cleaning processes and solutions. This method examines th
8、e reduction inthe number of spores as a tracer of foreign materials and not necessarily the reduction in organic soildirectly.This test may be designed to either examine the efficacy of a complete cleaning cycle consisting ofseveral integrated steps or individual cleaning step such as precleaning, m
9、anual cleaning, automatedcleaning or rinsing.1. Scope1.1 This test method is written principally for large medicalinstruments or instruments with internal channels or recesses(for example, flexible endoscopes) but may be used for anyresuable medical instruments.1.2 This test method describes a proce
10、dure for testing theefficacy of a cleaning process for reusable medical instrumentsartificially contaminated with mixtures of microorganisms andsimulated soil.1.3 The test method utilizes bacterial spores as tracers forforeign materials and quantifies their removal as a means ofdetermining the effic
11、acy of a cleaning process.1.4 The test method is designed for use by manufacturers ofmedical instruments and devices. However, it may also beemployed by other individuals who have a knowledge of theinstruments, techniques and access to appropriate facilities.1.5 Worst-case conditions can be represen
12、ted by exaggerat-ing a specific test parameter or otherwise intentionally simu-lating an extreme condition such as performing the test withoutcleaning solutions or utilizing instruments which are not new.1.6 The test procedure is devised to determine the efficacyof a cleaning process as applied to a
13、 particular instrument orgroup of instruments by simulating actual use situations.1.7 The test procedure may be performed on test instru-ments using a complete cleaning cycle or be limited toparticular phases of the cycle such as precleaning, manualcleaning, automated cleaning, or rinsing.1.8 The te
14、st procedure is normally performed on a numberof external and internal sites, but it may be restricted to oneparticular site on the instrument.1This test method is under the jurisdiction of ASTM Committee E35 onPesticides and Alternative Control Agents and is the direct responsibility ofSubcommittee
15、 E35.15 on Antimicrobial Agents.Current edition approved May 1, 2008. Published June 2008. Originallyapproved in 2003. Last previous edition approved in 2003 as E 2314 03.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.1.9 A knowledg
16、e of microbiological and aseptic techniquesand familiarity with the instruments is required to conductthese procedures.NOTE 1Because contamination of the surfaces of instruments mayoccur as a result of rinsing with tap water, bacteria-free water should beused for all rinsing when a water rinse step
17、is part of the cleaningdirections.NOTE 2Test methods to determine the effectiveness of cleaningmedical instruments has only recently been actively debated, and researchefforts are in their infancy. Because published experimental results arescarce, it is premature to dictate experimental reagents, co
18、nditions oracceptance criteria.NOTE 3The total elimination of the target organisms is not the goal ofcleaning. Therefore, there will almost always be a number of microorgan-isms surviving on the test instruments unless one of the solutions orprocesses disinfects or sterilizes the test instrument. Th
19、e results of variousclinical and laboratory tests suggest that cleaning processes alone canproduce a 102to 104log10reduction in bioburden. The exact reductionwill depend upon the precise experimental conditions. The criteria forjudging cleanliness should be determined and recorded before initiation
20、ofthe test procedure.NOTE 4This test protocol employs target spores as indicators ortracers for foreign materials and monitors their removal by the cleaningprocess. It is certainly possible that other particulate target materials, suchas microbeads (latex beads) could be used in place of microbes. T
21、hesealternate approaches would be more practical in those circumstanceswhere microbiological expertise is limited.1.10 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.11 This standard may involve hazardous materials, opera-tio
22、ns, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.
23、 Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterE 1054 Test Methods for Evaluation of Inactivators ofAntimicrobial AgentsE 1766 Test Method for Determination of Effectiveness ofSterilization Processes for Reusable Medical Devices2.2 Other Source:AAMI, TIR No. 30 ACompe
24、ndium of Processes, Materials,Test Methods, and Acceptance Criteria for Cleaning Re-usable Medical Devices33. Terminology3.1 Definitions:3.1.1 accessible locationa location on a reusable medicalinstrument(s) that may be contacted by bioburden, soil andcleaning agents.3.1.2 automated cleaningthe remo
25、val of foreign materialfrom medical instruments by means of a machine.3.1.3 bioburdenthe number and types of viable microor-ganisms that contaminate an instrument.3.1.4 CFUcolony forming units.3.1.5 cleaningthe removal of foreign materials, includingorganic soil (for example, protein) and microorgan
26、isms frommedical instruments.3.1.6 cleaning solutiona solution used to aid in theremoval of foreign matter from medical instruments.3.1.7 manual cleaningthe removal of foreign materialfrom a medical instrument without the aid of a machine.3.2 Definitions of Terms Specific to This Standard:3.2.1 clea
27、ning effcacythe efficacy of cleaning may becalculated as the log reduction of viable microorganismsrecovered from the test instruments as compared to the controlinstruments.3.2.2 control instrumentsreusable medical instrumentswhich are inoculated but not subjected to the Test Cycle.3.2.2.1 control i
28、nstrument recoverythe quantity of inocu-lum that can be recovered from the accessible locations (forexample, external surface sites and lumens, if any) of thecontrol instruments.3.2.3 neutralizera reagent used to stop the antimicrobialactivity of residual cleaning agent(s) that may be present ontest
29、 instruments and eluted along with the target microorgan-isms. (See Practices E 1054 for recommended neutralizers.)3.2.4 reusable medical instrumentany medical instrumentthat is claimed by the manufacturer to be usable after repro-cessing.3.2.5 test cyclea cleaning process that utilizes all of thepa
30、rameters selected by the tester.3.2.6 test instrumentsreusable medical instruments whichare inoculated and subjected to the Test Cycle. These instru-ments are used to determine the efficacy of the cleaningprocess.3.2.6.1 test instrument recoverythe quantity of inoculumthat can be recovered from the
31、accessible locations (forexample, external surface sites and lumens, if any) of the testinstruments.3.2.7 test soila formulation of organic materials used intesting the efficacy of cleaning.3.2.8 worst-casethe intentional exaggeration of one ormore parameters of a test compared to the normal conditi
32、on.For example, this could include exaggerated soil load ordeletion of cleaning steps.4. Summary of Test Method4.1 This test method is performed by inoculating interior orexterior surfaces, or both, of reusable medical instruments.4.2 Both control instruments and test instruments are usedin this tes
33、t method. Prior to inoculation, all instruments arecleaned and reprocessed. An inoculum with high numbers oftarget microorganisms suspended in test soil is applied to bothcontrol and test instruments.4.3 It is impractical to determine inoculum recovery byimmersion of large medical instruments or ins
34、truments withinternal channels or recesses (for example, flexible endo-scopes) in elution fluid because of their complexity, size, or2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume infor
35、mation, refer to the standards Document Summary page onthe ASTM website.3Available from Association for the Advancement of Medical Instrumentation(AAMI), 1110 North Glebe Road, Suite 220, Arlington, VA 22201-4795.E 2314 03 (2008)2deleterious effects from immersion. Therefore, rinsing orswabbing tech
36、niques are used to recover target microorganismsfrom these types of inoculated instruments.4.4 Control instruments are used to determine the number oforganisms which can be recovered from the instruments. Atleast two control instruments are inoculated in the samemanner as the test instruments, howev
37、er cleaning is notperformed. An appropriate recovery method (see 4.3) is thenused to determine the level of inoculum recoverable from theinstruments. At least 106CFU recoverable per instrument arerequired. For an instrument with lumens, the total number oforganisms recovered from both inside and out
38、side surfaces ofthe instrument will be defined as the control instrumentrecovery.4.5 After the Test Cycle has been completed using the testinstruments, the inoculated target microorganisms remainingon these instruments are recovered using the same elution,recovery and quantitation procedures used to
39、 determine thenumber of target microorganisms on the control instruments.By comparing this test instrument recovery to the controlinstrument recovery, the efficacy of the cleaning process maybe calculated.5. Significance and Use5.1 This test method is designed to evaluate the effective-ness of clean
40、ing reusable medical instruments using a specifiedcleaning process.5.2 This test method may be used to determine the effec-tiveness of cleaning processes of recesses, hinged sites, lumina,or other difficult-to-reprocess areas of reusable medical instru-ments.5.3 This test method may also be used to
41、verify the claimsfor any portion of the cleaning cycle.5.4 The recovery of surviving microorganisms may beaccomplished using swabbing, rinsing, or total immersion ofinstruments.5.5 The efficacy of the elution methods or loss of the appliedinoculum may be assessed by recovery of target organismsfrom
42、control instruments that have not been subjected to thecleaning process.6. Apparatus6.1 Syringes, 10 to 50 mL, sterile.6.2 Sterile Cotton or Dacron Swabs.6.3 Sterile Petri Dishes.6.4 Sterile Tubes, to hold 10 mL.6.5 Sterile Bottles, to hold 50 mL and sterile flasks to hold250 to 500 mL.6.6 Steriliza
43、tion Device, for the medical instruments beingexamined. Alternatively, supplies for high level disinfectionrecommended by the instrument manufacturer.6.7 Water Bath, which can maintain temperature from 20 to50 6 2C.6.8 Incubator(s), which maintain 37 6 2C (for B. atro-phaeus, formerly known as Bacil
44、lus subtilis subspecies niger)or temperature appropriate for selected target organism.6.9 Membrane Filters, 0.45 m, and filter supports for thefilters.6.10 Colony Counter.6.11 Disposable Plastic Pipettes, various sizes.6.12 Reusable Medical Instruments, reprocessed prior toeach use.6.13 Cleaning Dev
45、ices, accessories or apparatus to be usedin the Test Cycle and/or for reprocessing between uses asspecified by the manufacturer of the test instrument.6.14 Vortex Mixer and/or Sonicator.6.15 Vacuum Pump.6.16 Shaker and/or Stirrer.7. Reagents7.1 Media:7.1.1 Sterile USP Fluid D (Elution Fluid), contai
46、ningpolysorbate 80. Alternatively, sterile elution fluid solutioncontaining 0.4 g KH2PO4,10.1gNa2HPO4, and 1.0 gisooctylphenoxypolyethoxy ethanol (Triton X-100) prepared in1 L of Type III or better ASTM water adjusted to pH 7.8.Neutralizers appropriate for the cleaning solution may beadded to either
47、 of these solutions.7.1.2 Soybean-Casein Digest Broth, USP, with and withoutappropriate neutralizers for the specific test cleaning chemi-cal(s) in the cleaning solution.7.1.3 Soybean-Casein Digest Agar, USP, single or doublestrength with and without appropriate neutralizers in 10 to 50mL tubes or b
48、ottles tempered to 48 6 2C.7.1.4 Sterile Saline or Phosphate Buffer, for rinsing mem-brane filters.7.2 Target OrganismsStandardized suspensions of Bacil-lus atrophaeus endospores (ATCC 9372) containing nominally108CFU/mL should be used. Standardized bacterial sporesuspensions are commercially availa
49、ble. The origin of thespore strain, production, storage, and expiration dates shouldbe identified. Bacterial endospores are preferred as the targetstrain because they would be more resistant to potentialmicrobiocidal effects of the cleaning solutions. If other micro-organisms are used, appropriate changes in growth media andconditions should be made (also see requirements for ControlExperiments in 9.1.4.1).7.3 Type III or better ASTM Water, for making broth andelution fluids (see Specification D 1193).7.4 Rinse WaterWater prepared by either steam sterili
