1、Designation: E2720 10Standard Test Method 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 immediately following th
2、e 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 communicable diseas
3、es 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 (particle size and
4、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 effectiveness of surface d
5、econtaminants. This test method is designed to simulate thedeposition of droplet nuclei from human respiratory secretions onto and into air-permeablemembranes. It is primarily focused on influenza viruses but other respiratory viruses or surrogateviruses could be used. Protocols for assessing the mi
6、crobicidal activity of disinfectants are alsodescribed.1. Scope1.1 This test method is designed to evaluate decontamina-tion methods (physical, chemical, self-decontaminating mate-rials) when used on air-permeable materials contaminated withvirus-containing droplet nuclei.1.2 This test method define
7、s the conditions for simulatingrespiratory droplet nuclei produced by humans.1.3 The method is specific to influenza viruses but could beadapted for work with other types of respiratory viruses orsurrogates (Appendix X6).1.4 This test method is suitable only for air-permeablematerials.1.5 This test
8、method does not address the performance ofdecontaminants against microbes expelled via blood splatter,vomit, or fecal contamination.1.6 This test method should be performed only by thosetrained in bioaerosols, microbiology, or virology, or combina-tions thereof.1.7 The values stated in SI units are
9、to be regarded asstandard. No other units of measurement are included in thisstandard.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices a
10、nd determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1052 Test Method for Efficacy of Antimicrobial AgentsAgainst Viruses in SuspensionE2197 Quantitative Disk Carrier Test Method for Determin-ing the Bactericidal, Virucidal, Fungicidal, M
11、ycobacteri-cidal and Sporicidal Activities of Liquid Chemical Germi-cidesE2721 Test Method for Evaluation of Effectiveness ofDecontamination Procedures for Surfaces When Chal-lenged with Droplets Containing Human Pathogenic Vi-ruses2.2 IEST Standards:IEST-RP-CC003.3 Garment System Considerations for
12、Clean Rooms and Other Controlled Environments31This 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, 2010. Published February 2011. D
13、OI: 10.1520/E272010.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Institute of Environmenta
14、l Sciences and Technology (IEST),Arlington Place One, 2340 S. Arlington Heights Rd., Suite 100, Arlington Heights,IL 60005-4516, http:/www.iest.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.3 Department of Defense Standards:C
15、A06PRO411 Method for EvaluatingAir Purification Tech-nologies for Collective Protections Using Viable Micro-bial Aerosols42.4 EPA Standards:EPA 600/4-84/013 (N16) USEPA Manual of Methods forVirology52.5 WHO Standards:WHO Manual on Animal Influenza Diagnosis and Surveil-lance63. Terminology3.1 Defini
16、tions:3.1.1 aerosol, na suspension of solid or liquid particles ina gas medium.3.1.2 air-permeable material, nno standard definition isavailable; for the purpose of this test method, air-permeablematerial is described as any membrane that has a pressure drop#twice that of high efficiency particulate
17、 air (HEPA) media inthe same test environment.3.1.3 biological aerosol, naerosol comprising particles ofbiological origin or activity which may affect living thingsthrough infectivity, allergencity, toxicity, or pharmacologicaland other processes.3.1.4 influenza, nan infectious disease of birds and
18、mam-mals caused by RNA viruses of the family Orthomyxoviridae.3.1.5 protective factor, nsoluble or insoluble materialco-deposited with microorganisms that directly protects themicroorganism from environmental stresses or decontami-nants.3.1.6 respiratory droplet nuclei, nevaporatively con-densed, pa
19、thogen-containing particles of respiratory secretionsexpelled into the air by coughing, sneezing, or talking, whichcan remain airborne for long periods of time.3.1.7 self-sanitizing material, na substrate containing anantimicrobial agent that collectively acts as a germicide.4. Summary of Test Metho
20、d4.1 The test method describes the steps required to depositdroplet nuclei onto air-permeable membranes and quantita-tively assess decontamination efficiency.4.1.1 Using an aerosol device capable of meeting the dataquality objectives set for in this test method, influenza virus orsurrogates are aero
21、solized to form droplet nuclei that aresubsequently applied to air-permeable materials.4.1.2 The virus-contaminated carriers are subjected to dis-infection protocols and incubated for the specified time andconditions. Control samples are incubated under identicalconditions but are not exposed to the
22、 disinfection protocols.NOTE 1Carriers with incorporated microbicides do not receive anyadditional disinfection treatment. An untreated control is needed to assessantimicrobial efficacy.4.1.3 Virus particles are eluted from the test and controlcarriers and viability is assessed by tissue culture 50
23、%infectious dose assay (log10TCID50).NOTE 2Nonviable quantification techniques for viral enumerationsuch as polymerase chain reaction (PCR) or hemagglutination cannot beused.4.1.4 The virucidal activity of the decontamination proce-dure is determined from the log difference in viability betweentreat
24、ed and control carriers.5. Significance and Use5.1 The efficacy of disinfection technologies can be evalu-ated on finished products, as well as on developmental items.5.2 This test method defines procedures for validation of theaerosol generator, preparation of the test specimen, applicationof the c
25、hallenge virus, enumeration of viable viruses, assessingdata quality, and calculation of decontamination efficacy.5.3 This test method provides defined procedures for creat-ing droplet nuclei that approximate those produced by humanrespiratory secretions with particular emphasis on particle sizedist
26、ribution and aerosolization media.5.4 Safety concerns associated with aerosolizing microbialagents are not addressed as part of this test method. Individualusers should consult with their local safety authority, and adetailed biological aerosol safety plan and risk assessmentshould be conducted prio
27、r to using this method. Users areencouraged to consult the manual Biosafety in Microbiologicaland Biomedical Laboratories7published by the U.S. Centersfor Disease Control and Prevention (CDC).5.5 This test method differs from Test Methods E1052 andE2197 in the presentation of the virus to surface. T
28、he afore-mentioned test methods use liquid inoculum to contaminatecarrier surfaces, whereas this test method presents the virus inthe absence of water as droplet nuclei.5.6 This test method differs from Test Method E2721because (1) smaller particles are being formed, (2) the dropletswill be dried, t
29、hus forming droplet nuclei, prior to applicationto air-permeable materials, and (3) unique equipment is re-quired to create the droplet nuclei.4Foarde, K., Heimbuch, B. K., Maxwell, A., VanOsdell, D., “Method forEvaluating Air Purification Technologies for Collective Protection Using ViableMicrobial
30、 Aerosols,” Test Operating Procedure (TOP) Under the Army Test andEvaluation Command (ATEC), Edgewood Chemical and Biological Center, Edge-wood, Md., 2010 in press.5Available from United States Environmental Protection Agency (EPA), ArielRios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460,
31、http:/www.epa.gov.6Webster, R., Cox, N., Stohr, K. WHO Manual on Animal Influenza Diagnosisand Surveillance. World Health Organization, Department of Communicable Dis-ease Surveillance and Response. WHO/CDS/CDR/2002.5 Rev. 1.7CDC-NIH, Biosafety in Microbiological and Biomedical Laboratories, 5thEdit
32、ion, U.S. Department of Health and Human Services, Washington, D.C., 2009.E2720 1026. Apparatus6.1 Biological Aerosol GeneratorsThe apparatus to loadmicroorganisms onto a substrate is composed of severalcommercially available components and can be readily con-structed (see IEST-RP-CC003.3).4,8,9The
33、overall design of theapparatus can take various forms and can be fashioned indifferent dimensions while meeting the validation requirementsand data quality objectives listed below. Appendix X1 andAppendix X2 contain the description of a prototypical devicethat can be used to load droplet nuclei onto
34、 surfaces. However,it is the responsibility of the user of this standard to validate theperformance of the device prior to use.6.1.1 Validation requirements and baseline testing.6.1.1.1 Environmental ConditionsGenerator must be ca-pable of delivering air with a relative humidity of 70 6 10 %.6.1.1.2
35、 Leak TestThe device must maintain a positivepressure of 50 cm of water for at least 10 min.6.1.1.3 Flow Rate ConsistencyAll ports containing speci-men holders must maintain a constant flow with a coefficient ofvariation (CV) # 10 % over the duration of the samplingperiod.6.1.1.4 Loading uniformity
36、across the diameter of the testspecimen is required to ensure the even distribution of thedroplet nuclei over the surface of the carrier. A standarddeviation of 60.5 log10TCID50is desired.6.1.1.5 Sample-to-Sample VariationThe variability of vi-rus loading for multiple samples loaded for a single tes
37、t musthave a standard deviation of 60.5 log10TCID50.6.1.1.6 Droplet Nuclei CharacteristicsThe droplet nucleigenerated for this method will have a count median diameter(CMD) of 0.8 m. The virus will be aerosolized in a salivasubstitute (Table 1) that will add the appropriate “protectivefactors.” This
38、 test method would be suitable for simulatingother fluids of interest; however, if a different fluid is used, theformulation and recipe listing the protective factors and par-ticle size must be reported.6.2 Other EquipmentThe list is specific for influenzavirus. Other equipment may be needed if a di
39、fferent virus isused.6.2.1 Autoclave, capable of maintaining 121 to 123C and15 to 17 lbs per in.2gauge (psig).6.2.2 CO2Incubator, capable of maintaining 35 to 37C and5 6 0.5 % CO2.6.2.3 Vortex Mixer.6.2.4 Analytical Balance, capable of weighing 0.001 g.6.2.5 Refrigerator, capable of maintaining 2 to
40、 8C.6.2.6 Stopwatch or Electronic Timer.6.2.7 Pipettor, with a precision of 0.001 mL.7. Reagents and Materials7.1 ReagentsThe list is specific for influenza use. Otherreagents may be needed if a different virus is used.7.1.1 Influenzavirus (H1N1; A/PR/8/34)cell cultureadapted, ATCC VR-146.7.1.1.1 Th
41、e WHO Manual on Animal Influenza Diagnosisand Surveillance contains specific procedures for preparinginfluenza virus and titering samples. Appendix X3 also hasspecific information on titrating viable influenza viruses. Otherviruses may be used, but conditions for propagation andenumeration are not p
42、rovided in this method.7.1.2 MadinDarby Canine Kidney (MDCK) Cell Line,ATCC CRL-34.7.1.3 Artificial Saliva, see Table 1.7.1.4 Minimal Essential Medium With Earles BalancedSalts (EMEM).7.1.5 Heat-Inactivated Fetal Bovine Serum (45 min at56C).7.1.6 Penicillin/Streptomycin, 10 000 units penicillin and
43、10mg streptomycin per mL.7.1.7 L-Glutamine, 200 mM in 0.85 % 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 mMEDTA in Hanks balanced salts solution without sodium b
44、icar-bonate, calcium, and magnesium.7.1.14 Distilled Water and Purified Water.7.1.15 Ethanol, laboratory grade.7.1.16 Bleach.7.2 MaterialsThe list is specific for influenza use. Otherreagents may be needed if a different virus is used.7.2.1 Tissue Culture Treated FlasksT-25, T-75, T-175,24-well plat
45、e.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 accu-rately 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.8Heimbuc
46、h B. K., Wallace, W. H., Kinney, K., Lumley, A. E., Wu, C-Y, Woo,M-H, Wander, J. D., “A Pandemic Influenza Preparedness Study: Use of EnergeticMethods to Decontaminate Filtering Facepiece Respirators Contaminated withH1N1 Aerosols and Droplets,” American Journal of Infection Control, 2010, DOI10.101
47、6/j.ajic.2010.07.004.9Fisher E, Rengasamy S, Viscusi DJ, Vo E, Shaffer R., Development of a testsystem to apply virus-containing particles to filtering facepiece respirators for theevaluation of decontamination procedures, Appl Environ Microbiol, Vol 75, No. 6,2009, pp. 15001507.TABLE 1 Artificial S
48、alivaReagent AmountMgCl27H2O0.04gCaCl2H213NaHCO30.42 g0.2MKH2PO47.70 mL0.2MK2HPO412.3 mLNH4Cl 0.11 gKSCN 0.19 g(NH2)2CO 0.12 gNaCl 0.88 gKCl 1.04 gMucin 3.00 gDistilled water 1000 mLpH7E2720 1038. Sampling, Test Specimens, and Test Units8.1 Cut test specimens from finished products or fromspecimens
49、that can be documented as representative of finishedproducts. The configuration of the particular aerosol devicedictates the size and type of each specimen. Seal specimensinto the sample holder in the proper orientation. In some casesthe complete finished product may be used, which obviates theneed for cutting “coupons.” An airtight seal is required toprevent leakage of the aerosol around the sample.9. Experimental Design9.1 A minimum of three independent test and controlsamples must be evaluated so that fundamental statisticalanalysis of the
