1、Designation: E 2314 03Standard 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 designation indicates t
2、he 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 (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONCleaning is acknowledged as the critical first s
3、tep 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 sterilization proce
4、dures. 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 exaggerated to cr
5、eate worst-case conditions for the test.Among these are the amount or type of organic soil or micro-organisms contaminating theinstruments.The test method was developed primarily for large medical instruments or instruments with internalchannels or recesses (for example, flexible endoscopes) but may
6、 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 of organic soil
7、(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 the reduction inthe
8、 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, manual cleaning, a
9、utomatedcleaning 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 procedure for testing
10、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 efficacy of a cleaning
11、 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 represented by exaggerat-
12、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 particular instr
13、ument orgroup of instruments by simulating actual use situations.1This test method is under the jurisdiction of ASTM Committee E35 onPesticides and Alternative Control Agents and is the direct responsibility ofSubcommittee E35.15 on Antimicrobial Agents.Current edition approved Oct. 1, 2003. Publish
14、ed November 2003.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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, manualc
15、leaning, automated cleaning, or rinsing.1.8 The test procedure is normally performed on a numberof external and internal sites, but it may be restricted to oneparticular site on the instrument.1.9 A knowledge of microbiological and aseptic techniquesand familiarity with the instruments is required t
16、o 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 is part of the cleaningdirections.NOTE 2Test methods to determine the effectiveness of cleani
17、ngmedical 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, conditions oracceptance criteria.NOTE 3The total elimination of the target organisms is not the
18、 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. The results of variousclinical and laboratory tests suggest that cleaning processes alone canpr
19、oduce 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 ofthe test procedure.NOTE 4This test protocol employs target spores as indicators ortracers f
20、or 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. Thesealternate approaches would be more practical in those circumstanceswhere microbiological
21、expertise is limited.1.10 This standard may involve hazardous materials, opera-tions, 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 pr
22、actices and deter-mine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 1193 Specifications for Reagent WaterE 1054 Practices for Evaluation of Inactivators of Antimi-crobial Agents used in Disinfectant, Sanitizer, Antiseptic orPreserved ProductsE
23、1766 Test Method for Determination of Efficacy of Ster-ilization Processes for Reusable Medical Devices2.2 Other Source:AAMI, TIR No. 30 A Compendium of Processes, Materials,Test Methods, and Acceptance Criteria for Cleaning Re-usable Medical Devices23. Terminology3.1 Definitions:3.1.1 accessible lo
24、cationa location on a reusable medicalinstrument(s) that may be contacted by bioburden, soil andcleaning agents.3.1.2 automated cleaningthe removal of foreign materialfrom medical instruments by means of a machine.3.1.3 bioburdenthe number and types of viable microor-ganisms that contaminate an inst
25、rument.3.1.4 CFUcolony forming units.3.1.5 cleaningthe removal of foreign materials, includingorganic soil (for example, protein) and microorganisms frommedical instruments.3.1.6 cleaning solutiona solution used to aid in theremoval of foreign matter from medical instruments.3.1.7 manual cleaningthe
26、 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 cleaning effcacythe efficacy of cleaning may becalculated as the log reduction of viable microorganismsrecovered from the test instruments as compared to the co
27、ntrolinstruments.3.2.2 control instrumentsreusable medical instrumentswhich are inoculated but not subjected to the Test Cycle.3.2.2.1 control instrument recoverythe quantity of inocu-lum that can be recovered from the accessible locations (forexample, external surface sites and lumens, if any) of t
28、hecontrol instruments.3.2.3 neutralizera reagent used to stop the antimicrobialactivity of residual cleaning agent(s) that may be present ontest instruments and eluted along with the target microorgan-isms. (See Practices E 1054 for recommended neutralizers.)3.2.4 reusable medical instrumentany medi
29、cal instrumentthat is claimed by the manufacturer to be usable after repro-cessing.3.2.5 test cyclea cleaning process that utilizes all of theparameters selected by the tester.3.2.6 test instrumentsreusable medical instruments whichare inoculated and subjected to the Test Cycle. These instru-ments a
30、re used to determine the efficacy of the cleaningprocess.3.2.6.1 test instrument recoverythe quantity of inoculumthat can be recovered from the accessible locations (forexample, external surface sites and lumens, if any) of the testinstruments.3.2.7 test soila formulation of organic materials used i
31、ntesting the efficacy of cleaning.3.2.8 worst-casethe intentional exaggeration of one ormore parameters of a test compared to the normal condition.For example, this could include exaggerated soil load ordeletion of cleaning steps.4. Summary of Test Method4.1 This test method is performed by inoculat
32、ing interior orexterior surfaces, or both, of reusable medical instruments.4.2 Both control instruments and test instruments are usedin this test method. Prior to inoculation, all instruments arecleaned and reprocessed. An inoculum with high numbers oftarget microorganisms suspended in test soil is
33、applied to bothcontrol and test instruments.2Avaiable from, Association for the Advancement of Medical Instrumentation,(AAMI), 1110 North Glebe Road, Suite 220, Arlington, VA 22201-4795E23140324.3 It is impractical to determine inoculum recovery byimmersion of large medical instruments or instrument
34、s withinternal channels or recesses (for example, flexible endo-scopes) in elution fluid because of their complexity, size, ordeleterious effects from immersion. Therefore, rinsing orswabbing techniques are used to recover target microorganismsfrom these types of inoculated instruments.4.4 Control i
35、nstruments 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, however cleaning is notperformed. An appropriate recovery method (see 4.3) is thenused to determine the level
36、 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 outside surfaces ofthe instrument will be defined as the control instrumentrecovery.4.5 After the Test Cycl
37、e 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 determine thenumber of target microorganisms on the control instruments.By comparing this test instrume
38、nt recovery to the controlinstrument recovery, the efficacy of the cleaning process maybe calculated.5. Significance and Use5.1 This method is designed to evaluate the effectiveness ofcleaning reusable medical instruments using a specified clean-ing process.5.2 This method may be used to determine t
39、he effectivenessof cleaning processes of recesses, hinged sites, lumina, or otherdifficult-to-reprocess areas of reusable medical instruments.5.3 This method may also be used to verify the claims forany portion of the cleaning cycle.5.4 The recovery of surviving microorganisms may beaccomplished usi
40、ng 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 control instruments that have not been subjected to thecleaning process.6. Apparatus6.1 Syringes, 10 to 50 mL, sterile.6.2
41、 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 Sterilization Device, for the medical instruments beingexamined. Alternatively, supplies for high level disinfectionrecommended by
42、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 Bacillus subtilis subspecies niger)or temperature appropriate for selected target organism.6.9 Membrane Filters, 0.45 m, and fi
43、lter 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 Devices, accessories or apparatus to be usedin the Test Cycle and/or for reprocessing between uses asspecified by the manufac
44、turer 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), containingpolysorbate 80. Alternatively, sterile elution fluid solutioncontaining 0.4 g KH2PO4,10.1gNa2HPO4, and 1.0 gisooctylph
45、enoxypolyethoxy 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 of these solutions.7.1.2 Soybean-Casein Digest Broth, USP, with and withoutappropriate neutralizers for the specific test
46、 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 bottles tempered to 48 6 2C.7.1.4 Sterile Saline or Phosphate Buffer, for rinsing mem-brane filters.7.2 Target OrganismsSta
47、ndardized suspensions of Bacil-lus atrophaeus endospores (ATCC 9372) containing nominally108CFU/mL should be used. Standardized bacterial sporesuspensions are commercially available. The origin of thespore strain, production, storage, and expiration dates shouldbe identified. Bacterial endospores ar
48、e 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
49、 or better ASTM Water, for making broth andelution fluids (see Specification D 1193).7.4 Rinse WaterWater prepared by either steam steriliza-tion or by 0.2 m filtration (when a water-rinse step is part ofthe cleaning process).7.5 Test SoilSoil consisting of serum or solutions ofserum proteins. These may be used alone or combined withother types of organic soil.7.6 Cleaning SolutionThe cleaning solution used in theTest Cycle.7.7 Neutralizers (as appropriate)Chemical inactivatorswhich interrupt the killing action of the cleaning agent. (SeePractices E 1054 f
