1、Designation: E1766 95 (Reapproved 2007)E1766 15Standard Test Method forDetermination of Effectiveness of Sterilization Processes forReusable Medical Devices1This standard is issued under the fixed designation E1766; the number immediately following the designation indicates the year oforiginal adopt
2、ion 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 covers a reproducible procedure for testing processes us
3、ed to sterilize reusable medical devices(instruments). This test method is not designed to validate a sterilization process, but tests an established sterilization cycle orprocess. It is a practical test of the effectiveness of a sterilization process applied to reusable medical devices. Bacterial s
4、pores moreresistant to the test sterilant than the natural bioburden of the instrument are used as the test organisms. Commercially availableliquid suspensions of bacterial spores are used to inoculate the instruments.1.2 This test method is intended for reusable medical devices cleaned in accordanc
5、e with the device manufacturers instructionsand prepared for sterilization in accordance with the instructions for the sterilization process being used.1.3 This test method assumes that cleaned, reusable medical devices will be free of visible soil but may have remaining adherentbioburden. A worst-c
6、ase bioburden can be represented by suspensions of bacterial endospores, which are commercially availablefor monitoring chemical or physical sterilization processes. These endospores should have a verifiable resistance (D value) to thespecific process and sterilant being evaluated.21.4 It is impract
7、ical to test for the sterility of some devices by immersion in growth medium because of their complexity, size,and availability (for long-term incubation) or adverse effects on the devices from long-term immersion. Therefore, elution, rinsing,or swabbing techniques are used to recover test organisms
8、 from inoculated devices.1.5 A recovery control will be included by inoculation of a test device and use of the elution methods without applying thesterilization process being tested.Aminimal recovery of 106 colony-forming unit (CFU)/mLper device is required for the recoverycontrol.1.6 Results of th
9、e recovery control and process test cycle are compared to determine the effectiveness of the sterilizationprocess.1.7 Results of the recovery control and applied inoculum are compared to determine the recovery efficiency, if desired.1.8 The procedure should reveal that tested devices are free of rec
10、overable microorganisms when five or more consecutive testsare conducted.1.9 A knowledge of microbiological techniques is required to conduct these procedures.1.10 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.1.11 This
11、standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1
12、 ASTM Standards:3D1193 Specification for Reagent Water1 This test method is under the jurisdiction of ASTM Committee E35 on Pesticides, Antimicrobials, and Alternative Control Agents and is the direct responsibility ofSubcommittee E35.15 on Antimicrobial Agents.Current edition approved Nov. 1, 2007M
13、ay 1, 2015. Published November 2007December 2015. Originally approved in 1995. Last previous edition approved in 20022007as E1766 95 (2002).(2007). DOI: 10.1520/E1766-95R07.10.1520/E1766-15.2 Oxborrow, G. S., and Berube, R., “Sterility TestingValidation of Sterilization Processes, and Sporicide Test
14、ing,” Disinfection, Sterilization, and Preservation, Block,S. S., 4th Edition, Lea and Febiger, Philadelphia, PA, 1991, pp. 10471058.Oxborrow, G. S., and Berube, R., “Sterility TestingValidation of Sterilization Processes, andSporicide Testing,” Disinfection, Sterilization, and Preservation, Block,
15、S. S., 4th Edition, Lea and Febiger, Philadelphia, PA, 1991, pp. 10471058.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the
16、ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users cons
17、ult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E1054 Test Methods for Evaluation o
18、f Inactivators of Antimicrobial Agents2.2 Other:ASTM Poster Presentation : “Use Verification of a Proposed Draft ASTM Standard to Determine the Efficacy of SterilizationTechniques for Reusable Medical Instruments” Presented at the E35.15 Subcommittee meeting in Montreal, Canada3. Terminology3.1 Defi
19、nitions:3.1.1 bioburdenthe number and types of viable microorganisms that contaminate a device.3.1.2 CFUcolony-forming unit.3.1.3 inoculumthe number (usually specified as CFUs) and type (genus and species) of viable microorganisms used tocontaminate a given sample or device.3.1.4 sporicidal agentany
20、 chemical or physical agent that kills spores.3.1.5 sterilantany sterilizing agent.3.1.6 sterilea state of being free of living organisms.3.1.7 sterilization cycle or processa physical or chemical process that has been demonstrated to meet applicable criteria forsterilization as defined by AAMI.43.1
21、.8 sterilizerany device using a chemical or physical process that produces sterile materials.3.2 Definitions of Terms Specific to This Standard:3.2.1 applied inoculumthe estimated count of the suspension of bacterial spores expressed as CFU/mL used to inoculate thetest devices. This value may be use
22、d if the efficiencies of the recovery methods are determined.3.2.2 process test cyclea complete sterilization cycle that uses all parameters of the sterilization process as dictated by themanufacturer.3.2.3 recovery controlthe CFU recoverable from a device following inoculation and optional drying o
23、f the spore suspensionin or on the unprocessed device. The recovery of 106 CFUs per device is required.3.2.4 recovery effciencya measure of the recovery of inoculated organisms from a device may be determined when necessary.The recovery efficiency may be expressed as the ratio of the CFU from the re
24、covery control compared to the CFU of the appliedinoculum. This value is multiplied by 100 to express efficiency as a percent. It is recommended that a minimum of three tests beperformed when estimating recovery efficiency.3.2.5 reusable medical devicesany medical device that is claimed to be usable
25、 after reprocessing.3.2.6 sporea bacterial endospore. (Strain identification and the means used to identify whether the vegetative or spore stateis present should be indicated.)3.2.7 worst-casethe intentional exaggeration of one or more parameters of a test compared to normal clinical conditions.4.
26、Summary of Test Method4.1 Percent recovery of inoculum may be used to ensure reproducible inoculation and recovery techniques.4.2 The test method is performed by contaminating the cleaned reusable medical device with a bacterial endospore suspension.4.3 After inoculation, and drying, if required, th
27、e device is prepared and processed according to the sterilant or sterilizermanufacturers instructions.4.4 Following the sterilization process, the test devices are sampled using specified elution techniques to recover any survivingspores.5. Significance and Use5.1 The test method is designed to demo
28、nstrate that all accessible surfaces and internal recesses or lumina of previously cleaned,reusable medical devices can be rendered free of recoverable microorganisms when processed in a specified sterilizer cycle.5.2 Surviving spores are recovered by swabbing, brushing, or irrigating with an elutio
29、n fluid. Recovery methods may beenhanced by mechanical action, sonication, and repeated flushing with elution fluid.NOTE 1The spore inoculation technique described in this test method is only one of the available procedures for testing the sterilization of devices.Spores on paper strips (biological
30、indocators) are a traditional tool used to develop and monitor sterilization cycles and are also appropriate for theevaluation of sterilization of medical devices.54 See “Guideline for Industrial Ethylene Oxide Sterilization of Medical Devices” (ST27), AAMI, Arlington, VA, 1992, for typical criteria
31、.5 United States Pharmacopeia, XXIII, Rand McNally, Taunton, MA, 1995, pp. 200206.United States Pharmacopeia, XXIII, or current edition, Rand McNally, Taunton,MA, 1995, pp. 200206.E1766 1526. Apparatus6.1 Syringes, 10 to 50 mL, sterile.6.2 Sterile Cotton Swabs.6.3 Sterile Petri Dishes.6.4 Sterile Te
32、st Tubes, to hold 10 mL.6.5 Sterile Glass Bottles, to hold 50 mL.6.6 Steam Sterilizer.6.7 Water Bath, 48 6 2C.6.8 Incubator(s), 35 6 2C and 55 6 2C.6.9 Colony Counter.6.10 Medical Device, precleaned in accordance with the manufacturers instructions.6.11 Disposable or Reusable Membrane Filter Apparat
33、us, sterile, 0.45-m pore size.6.12 Micropipette, calibrated to dispense 5 to 20 L.6.13 Other devices or apparatus specified by the sterilant, medical device, or sterilizer manufacturer.7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it
34、 is intended that allreagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where suchspecifications are available.6 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purityto permit its use wi
35、thout lessening the accuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water as defined byType III of Specification D1193.7.3 Media:7.3.1 Type III or Better ASTM Water, for making broths and elution fluids.7.3.2 Steril
36、e USP Fluid D7(elution fluid), containing polysorbate 80 or stripping solution8 containing 0.4 g KH2PO4, 10.1 gNa2HPO4, and 1.0 g.7.3.3 Isooctylphenoxypolyethoxy Ethanol (Triton X-100), in 1-L distilled water adjusted to pH 7.8.7.3.4 Soybean-Casein Digest Broth, USP, single or double strength, with
37、neutralizers for the test sterilant, as appropriate, anda volume acceptable for each test.7.3.5 Soybean-Casein Digest Agar, USP, single or double strength, with neutralizers for the test sterilant, if appropriate; 10 to50 mL in tubes or bottles, tempered to 48 6 2C.7.4 Test Organisms/Spore Suspensio
38、n:7.4.1 For moist heat sterilization, standardized spore suspensions of BacillusGeobacillus stearothermophilus containingnominally 108 CFU/mL and meeting USP resistance criteria for steam sterilization should be used.97.4.2 For chemical or dry heat sterilization, standardized spore suspensions of Ba
39、cillus subtilisatrophaeus containing nominally108 CFU/mL and meeting USP resistance criteria for ethylene oxide or dry heat sterilization should be used.87.4.3 For sterilants in which either of the above organisms may be inappropriate, other indicator organisms may be substituted,provided there is s
40、ubstantial evidence evidence, and experimental data to indicate that they are more appropriate.7.4.4 The origin of the spore strain, production, storage, and expiration dates should be identified.7.5 Neutralizers (as appropriate)See Practices E1054 for recommended neutralizers.6 Reagent Chemicals, A
41、merican Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalForm
42、ulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD.7 United States Pharmacopeia, XXII, “Sterility Tests, Diluting and Rinsing Fluids,” Rand McNally, Taunton, MA, 1990, p. 1484.United States Pharmacopeia XXII, orcurrent edition, “Sterility Tests, Diluting and Rinsing Fluids,” Rand McNa
43、lly, Taunton, MA, 1990, p. 1484.8 Williamson, P., “Quantitative Estimation of Cutaneous Bacteria,” Skin Bacteria and Their Role in Infection, Marbac, H. I., and Hildick-Smith, G., eds., McGraw-Hill,New York, NY, 1965.Williamson, P., “Quantitative Estimation of Cutaneous Bacteria,” Skin Bacteria and
44、Their Role in Infection, Maibach, H. I., and Hildick-Smith, G., eds.,McGraw-Hill, New York, NY, 1965.9 United States Pharmacopeia, XXII, “Sterilized Instruments,” pp. 14861487; “Biological Indicator for Ethylene Oxide Sterilization, Paper Strip,” pp. 171173; and“Biological Indicator for Steam Steril
45、ization, Paper Strip,” pp. 173175, Rand McNally, Taunton, MA.United States Pharmacopeia XXII, or current edition, “SterilizedInstruments,” pp. 14861487; “Biological Indicator for Ethylene Oxide Sterilization, Paper Strip,” pp. 171173; and “Biological Indicator for Steam Sterilization, PaperStrip,” p
46、p. 173175, Rand McNally, Taunton, MA.E1766 1538. Procedure8.1 Select the devices to be evaluated.8.2 Read the cleaning instructions for each medical device to be tested, and ensure that all required accessories are available.Clean and dry the device according to the device manufacturers instructions
47、.8.3 Inoculate the device and include the sites most difficult to sterilize. The number of sites may vary with the complexity ofthe medical device. The rationale used to identify and verify the most difficult to sterilize sites must be documented. Inoculationprocedures producing a recoverable count
48、of 106 CFU spores per instrument should be used.8.4 Specific procedures are used for inoculation, elution, control testing, neutralization, growth promotion, and sterility testing.8.5 Inoculation of Devices to Determine the Applied InoculumThese paragraphs describe the steps for enumerating the CFUo
49、f spores inoculated onto the medical device being tested. The spores are not subjected to drying or other treatments, as they mightbe when determining the recovery control (see 8.6).8.5.1 Surface Site Inoculation:8.5.1.1 Micropipetter MethodInoculate the surface directly by introducing a volume of spore suspension containing 107spores to the site(s), and distribute over the inoculated site(s) with the tip of the pipet. Immerse the device in elution fluid or rinseimmediately, or swab the inoculum into a test tube or other sterile con
