1、Designation: E2720 10E2720 16Standard Test Method Practice forEvaluation of Effectiveness of Decontamination Proceduresfor Air-Permeable Materials when Challenged with BiologicalAerosols Containing Human Pathogenic Viruses1This standard is issued under the fixed designation E2720; the number immedia
2、tely 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.INTRODUCTIONMany co
3、mmunicable diseases are often spread through the aerosol route of exposure. The dropletnuclei formed in these aerosols may infect susceptible individuals directly or contaminate environ-mental surfaces and render them fomites for further spread of disease. The characteristics of thedroplet nuclei (p
4、article size and composition) will influence the viability of microorganisms whenexposed to environmental stresses but may also shield them from physical and chemical decontami-nants. The wide variations in the types and levels of such protective/shielding ingredients can haveimpact on the effective
5、ness of surface decontaminants. This test method practice is designed tosimulate the deposition of droplet nuclei from human respiratory secretions onto and into air-permeable membranes. It is primarily focused on influenza viruses but other respiratory viruses orsurrogate viruses could be used. Pro
6、tocols for assessing the microbicidal activity of disinfectants arealso described.1. Scope1.1 This test method is designed to evaluate decontamination methods (physical, chemical, self-decontaminating materials)when used on air-permeable materials contaminated with virus-containing droplet nuclei.1.
7、2 This test method defines the conditions for simulating respiratory droplet nuclei produced by humans.1.3 The method is specific to influenza viruses but could be adapted for work with other types of respiratory viruses orsurrogates (Appendix X6).1.4 This test method is suitable only for air-permea
8、ble materials.1.5 This test method does not address the performance of decontaminants against microbes expelled via blood splatter, vomit,or fecal contamination.1.6 This test method should be performed only by those trained in bioaerosols, microbiology, or virology, or combinationsthereof.1.7 The va
9、lues stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.8 This 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
10、 safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1052 Test Method to Assess the Activity of Microbicides against Viruses in Suspension1 This test method practice is under the jurisdiction ofASTM Committee E
11、35 on Pesticides,Antimicrobials, andAlternative ControlAgents and is the direct responsibilityof Subcommittee E35.15 on Antimicrobial Agents.Current edition approved Oct. 1, 2010April 1, 2016. Published February 2011May 2016. Originally approved in 2010. Last previous edition approved in 2010 as E27
12、2010.DOI: 10.1520/E272010.10.1520/E272016.2 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 ASTM website.This document is no
13、t 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 consult prior editions as appropriat
14、e. 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 States1E2197 Quantitative Disk Carrier Test Method for Determining Bacteri
15、cidal, Virucidal, Fungicidal, Mycobactericidal, andSporicidal Activities of ChemicalsE2721 Practice for Evaluation of Effectiveness of Decontamination Procedures for Surfaces When Challenged with DropletsContaining Human Pathogenic Viruses2.2 IEST Standards:IEST-RP-CC003.3 Garment System Considerati
16、ons for Clean Rooms and Other Controlled Environments32.3 Department of Defense Standards:CA06PRO411 Method for EvaluatingAir Purification Technologies for Collective Protections Using Viable MicrobialAerosols42.4 EPA Standards:EPA 6004-84013 (N16) USEPA Manual of Methods for Virology52.5 WHO Standa
17、rds:WHO Manual on Animal Influenza Diagnosis and Surveillance63. Terminology3.1 Definitions:3.1.1 aerosol, na suspension of solid or liquid particles in a gas medium.3.1.2 air-permeable material, nno standard definition is available; for the purpose of this test method, air-permeable materialis desc
18、ribed as any membrane that has a pressure drop twice that of high efficiency particulate air (HEPA) media in the sametest environment.3.1.3 biological aerosol, naerosol comprising particles of biological origin or activity which may affect living things throughinfectivity, allergencity, toxicity, or
19、 pharmacological and other processes.3.1.4 influenza, nan infectious disease of birds and mammals caused by RNA viruses of the family Orthomyxoviridae.3.1.5 protective factor, nsoluble or insoluble material co-deposited with microorganisms that directly protects themicroorganism from environmental s
20、tresses or decontaminants.3.1.6 respiratory droplet nuclei, nevaporatively condensed, pathogen-containing particles of respiratory secretions expelledinto the air by coughing, sneezing, or talking, which can remain airborne for long periods of time.3.1.7 self-sanitizing material, na substrate contai
21、ning an antimicrobial agent that collectively acts as a germicide.4. Summary of Test Method4.1 The test method describes the steps required to deposit droplet nuclei onto air-permeable membranes and quantitativelyassess decontamination efficiency.4.1.1 Using an aerosol device capable of meeting the
22、data quality objectives set for in this test method, influenza virus orsurrogates are aerosolized to form droplet nuclei that are subsequently applied to air-permeable materials.4.1.2 The virus-contaminated carriers are subjected to disinfection protocols and incubated for the specified time and con
23、ditions.Control samples are incubated under identical conditions but are not exposed to the disinfection protocols.NOTE 1Carriers with incorporated microbicides do not receive any additional disinfection treatment. An untreated control is needed to assessantimicrobial efficacy.4.1.3 Virus particles
24、are eluted from the test and control carriers and viability is assessed by tissue culture 50 % infectious doseassay (log10TCID50).NOTE 2Nonviable quantification techniques for viral enumeration such as polymerase chain reaction (PCR) or hemagglutination cannot be used.4.1.4 The virucidal activity of
25、 the decontamination procedure is determined from the log difference in viability between treatedand control carriers.5. Significance and Use5.1 The efficacy of disinfection technologies can be evaluated on finished products, as well as on developmental items.5.2 This test method defines procedures
26、for validation of the aerosol generator, preparation of the test specimen, application ofthe challenge virus, enumeration of viable viruses, assessing data quality, and calculation of decontamination efficacy.3 Available from Institute of Environmental Sciences and Technology (IEST), Arlington Place
27、 One, 2340 S. Arlington Heights Rd., Suite 100, Arlington Heights, IL60005-4516, http:/www.iest.org.4 Foarde, K., Heimbuch, B. K., Maxwell, A., VanOsdell, D., “Method for Evaluating Air Purification Technologies for Collective Protection Using Viable MicrobialAerosols,” Test Operating Procedure (TOP
28、) Under the Army Test and Evaluation Command (ATEC), Edgewood Chemical and Biological Center, Edgewood, Md., 2010 inpress.5 Available from United States Environmental Protection Agency (EPA), Ariel Rios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http:/www.epa.gov.6 Webster, R., Cox, N.
29、, Stohr, K. WHO Manual on Animal Influenza Diagnosis and Surveillance. World Health Organization, Department of Communicable DiseaseSurveillance and Response. WHO/CDS/CDR/2002.5 Rev. 1.E2720 1625.3 This test method provides defined procedures for creating droplet nuclei that approximate those produc
30、ed by humanrespiratory secretions with particular emphasis on particle size distribution and aerosolization media.5.4 Safety concerns associated with aerosolizing microbial agents are not addressed as part of this test method. Individual usersshould consult with their local safety authority, and a d
31、etailed biological aerosol safety plan and risk assessment should beconducted prior to using this method. Users are encouraged to consult the manual Biosafety in Microbiological and BiomedicalLaboratories7 published by the U.S. Centers for Disease Control and Prevention (CDC).5.5 This test method di
32、ffers from Test Methods E1052 and E2197 in the presentation of the virus to surface. The aforementionedtest methods use liquid inoculum to contaminate carrier surfaces, whereas this test method presents the virus in the absence ofwater as droplet nuclei.5.6 This test method differs from Test Method
33、E2721 because (1) smaller particles are being formed, (2) the droplets will bedried, thus forming droplet nuclei, prior to application to air-permeable materials, and (3) unique equipment is required to createthe droplet nuclei.6. Apparatus6.1 Biological Aerosol GeneratorsThe apparatus to load micro
34、organisms onto a substrate is composed of severalcommercially available components and can be readily constructed (see IEST-RP-CC003.3).4,8,9 The overall design of theapparatus can take various forms and can be fashioned in different dimensions while meeting the validation requirements and dataquali
35、ty objectives listed below. Appendix X1 and Appendix X2 contain the description of a prototypical device that can be usedto load droplet nuclei onto surfaces. However, it is the responsibility of the user of this standard to validate the performance ofthe device prior to use.6.1.1 Validation require
36、ments and baseline testing.6.1.1.1 Environmental ConditionsGenerator must be capable of delivering air with a relative humidity of 70 6 10 %.6.1.1.2 Leak TestThe device must maintain a positive pressure of 50 cm of water for at least 10 min.6.1.1.3 Flow Rate ConsistencyAll ports containing specimen
37、holders must maintain a constant flow with a coefficient ofvariation (CV) 10 % over the duration of the sampling period.6.1.1.4 Loading uniformity across the diameter of the test specimen is required to ensure the even distribution of the dropletnuclei over the surface of the carrier. A standard dev
38、iation of 60.5 log10TCID50 is desired.6.1.1.5 Sample-to-Sample VariationThe variability of virus loading for multiple samples loaded for a single test must havea standard deviation of 60.5 log10TCID50.6.1.1.6 Droplet Nuclei CharacteristicsThe droplet nuclei generated for this method will have a coun
39、t median diameter (CMD)of 0.8 m. The virus will be aerosolized in a saliva substitute (Table 1) that will add the appropriate “protective factors.” Thistest method would be suitable for simulating other fluids of interest; however, if a different fluid is used, the formulation and recipelisting the
40、protective factors and particle size must be reported.6.2 Other EquipmentThe list is specific for influenza virus. Other equipment may be needed if a different virus is used.6.2.1 Autoclave, capable of maintaining 121 to 123C and 15 to 17 lbs per in.2gauge (psig).6.2.2 CO2 Incubator, capable of main
41、taining 35 to 37C and 5 6 0.5 % CO2.7 CDC-NIH, Biosafety in Microbiological and Biomedical Laboratories, 5th Edition, U.S. Department of Health and Human Services, Washington, D.C., 2009.8 Heimbuch B. K., Wallace, W. H., Kinney, K., Lumley,A. E., Wu, C-Y, Woo, M-H, Wander, J. D., “APandemic Influenz
42、a Preparedness Study: Use of Energetic Methodsto Decontaminate Filtering Facepiece Respirators Contaminated with H1N1 Aerosols and Droplets,” American Journal of Infection Control, 2010, DOI 10.1016/j.ajic.2010.07.004.9 Fisher E, Rengasamy S, Viscusi DJ, Vo E, Shaffer R., Development of a test syste
43、m to apply virus-containing particles to filtering facepiece respirators for the evaluationof decontamination procedures, Appl Environ Microbiol, Vol 75, No. 6, 2009, pp. 15001507.TABLE 1 Artificial Saliva8Reagent AmountMgCl2 7 H2O 0.04 gCaCl2 H2O 0.13 gNaHCO3 0.42 g0.2 M KH2PO4 7.70 mL0.2 M K2HPO4
44、12.3 mLNH4Cl 0.11 gKSCN 0.19 g(NH2)2CO 0.12 gNaCl 0.88 gKCl 1.04 gMucin 3.00 gDistilled water 1000 mLpH 7E2720 1636.2.3 Vortex Mixer.6.2.4 Analytical Balance, capable of weighing 0.001 g.6.2.5 Refrigerator, capable of maintaining 2 to 8C.6.2.6 Stopwatch or Electronic Timer.6.2.7 Pipettor, with a pre
45、cision of 0.001 mL.7. Reagents and Materials7.1 ReagentsThe list is specific for influenza use. Other reagents may be needed if a different virus is used.7.1.1 Influenzavirus (H1N1; A/PR/8/34)cell culture adapted, ATCC VR-146.7.1.1.1 The WHO Manual onAnimal Influenza Diagnosis and Surveillance conta
46、ins specific procedures for preparing influenzavirus and titering samples. Appendix X3 also has specific information on titrating viable influenza viruses. Other viruses may beused, but conditions for propagation and enumeration are not provided in this method.7.1.2 MadinDarby Canine Kidney (MDCK) C
47、ell Line, ATCC CRL-34.7.1.3 Artificial Saliva, see Table 1.7.1.4 Minimal Essential Medium With Earles Balanced Salts (EMEM).7.1.5 Heat-Inactivated Fetal Bovine Serum (45 min at 56C).7.1.6 Penicillin/Streptomycin, 10 000 units penicillin and 10 mg streptomycin per mL.7.1.7 L-Glutamine, 200 mM in 0.85
48、 % NaCl.7.1.8 Crystal Violet.7.1.9 Glutaraldehyde.7.1.10 TPCKTrypsin.7.1.11 Phosphate Buffered Saline (PBS).7.1.12 Bovine Serum Albumin.7.1.13 TrypsinEDTA Solution, 0.05 % trypsin, 0.53 mM EDTA in Hanks balanced salts solution without sodium bicarbonate,calcium, and magnesium.7.1.14 Distilled Water
49、and Purified Water.7.1.15 Ethanol, laboratory grade.7.1.16 Bleach.7.2 MaterialsThe list is specific for influenza use. Other reagents may be needed if a different virus is used.7.2.1 Tissue Culture Treated FlasksT-25, T-75, T-175, 24-well plate.7.2.2 Pipettes, 1, 5, 10, and 25 mL.7.2.3 Test Tube Rack.7.2.4 Micropipettes, capable of delivering 0.001 mL accurately and consistently.7.2.5 1.7-mL Sterile Microcentrifuge Tubes.7.2.6 15-mL Sterile Centrifuge Tubes.7.2.7 50-mL Sterile Centrifuge Tubes.7.2.8 Air-Permeable Test Materials.8. S
