1、Designation: E3135 18Standard Practice forDetermining Antimicrobial Efficacy of Ultraviolet GermicidalIrradiation Against Microorganisms on Carriers withSimulated Soil1This standard is issued under the fixed designation E3135; the number immediately following the designation indicates the year ofori
2、ginal 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.1. Scope1.1 This practice will define test conditions to evaluateultraviol
3、et germicidal irradiation (UVGI) light devices (mer-cury vapor bulbs, light-emitting diodes, or xenon arc lamps)that are designed to kill/inactivate microorganisms depositedon inanimate carriers.1.2 This practice defines the terminology and methodologyassociated with the ultraviolet (UV) spectrum an
4、d evaluatingUVGI dose.1.3 This practice defines the testing considerations that canreduce UVGI surface kill effectiveness, that is, presence of asoiling agent.1.4 This practice does not address shadowing.1.5 This practice should only be used by those trained inmicrobiology and in accordance with the
5、 guidance provided byBiosafety in Microbiological and Biomedical Laboratories (5thedition), 2009, HHS Publication No. (CDC) 21-1112.1.6 This practice does not recommend either specific testmicrobes or growth media. Users of this practice shall selectappropriate test microbes and growth media based o
6、n thespecific objectives of their UV antimicrobial performanceevaluation test plan.1.7 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.8 WarningMercury has been designated by many regu-latory agencies as a hazardous substance
7、that can cause seriousmedical issues. Mercury, or its vapor, has been demonstrated tobe hazardous to health and corrosive to materials. Cautionshould be taken when handling mercury and mercury-containing products. See the applicable product Safety DataSheet (SDS) for additional information. Users sh
8、ould be awarethat selling mercury or mercury-containing products, or both,may be prohibited by local or national law.1.9 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-priat
9、e safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.10 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopm
10、ent of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E1053 Test Method to Assess Virucidal Activity of Chemi-cals Intended for Disinfection of Inanimate, NonporousEnvir
11、onmental SurfacesE1153 Test Method for Efficacy of Sanitizers Recommendedfor Inanimate, Hard, Nonporous Non-Food Contact Sur-facesE1316 Terminology for Nondestructive ExaminationsE2756 Terminology Relating to Antimicrobial and AntiviralAgentsE2721 Practice for Evaluation of Effectiveness of Decon-ta
12、mination Procedures for Surfaces When Challengedwith Droplets Containing Human Pathogenic VirusesG130 Test Method for Calibration of Narrow- and Broad-Band Ultraviolet Radiometers Using a Spectroradiometer2.2 ISO Standards:39370 Plastics - Instrumental Determination of Radiant Ex-posure in Weatherin
13、g Tests - General Guidance and BasicTest Method1This practice 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 May 1, 2018. Published Ju
14、ly 2018. DOI: 10.1520/E3135182For 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 International Or
15、ganization for Standardization (ISO), ISOCentral Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,Geneva, Switzerland, http:/www.iso.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was
16、developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.121348 Space En
17、vironment (Natural and Artificial) Processfor Determining Solar Irradiances2.3 AOAC Methods:4961.02 Germicidal Spray Products as Disinfectants3. Terminology3.1 For Definitions of Terms used in this practice, refer toTerminologies in E1316, E2756, and ISO 21348:3.2 Definitions:3.2.1 carrier, na surro
18、gate surface or matrix that facili-tates the interaction of test microorganisms and treatment(s).3.2.2 irradiance (E), na radiometric term for the radiantflux that is incident upon a surface (Wm-2).3.2.3 joule (J), na unit of work or energy in the SI systemof units.3.2.3.1 DiscussionOne Joule is one
19、 watt-second.3.2.4 light-emitting diode (LED), na solid-state electronicdevice or transistor which emits light.3.2.4.1 DiscussionAn LED is a p-n junction diode, whichemits light when activated. When a suitable voltage is appliedto the leads, electrons are able to recombine with electron holeswithin
20、the device, releasing energy in the form of photons.3.2.5 mercury vapor lamp, na gas discharge lamp thatuses electric arc through vaporized mercury to produce light.3.2.6 radiometer, na device for measuring the radiantpower that has an output proportional to the intensity of theinput power.3.2.7 sha
21、dowing, vcreating a dark area or shape byblocking light rays.3.2.8 soiling agent, nsubstance applied either along withor on top of the test microorganism that can reduce theeffectiveness of the antimicrobial technology.3.2.9 ultraviolet germicidal irradiation (UVGI), namethod that uses short-wavelen
22、gth ultraviolet (UV-C) light tokill or inactivate microorganisms primarily by forming pyrimi-dine dimers, leaving them unable to perform vital cellularfunctions.3.2.10 ultraviolet (UV) light, nradiation having wave-lengths shorter than wavelengths of visible light (400 nm) andlonger than those of X-
23、rays (100 nm).3.2.11 UV-A, nradiation within the ultraviolet spectrumthat extends from approximately 315 to 400 nm in wavelength.3.2.12 UV-B, nradiation within the ultraviolet spectrumthat extends from approximately 280 to 315 nm in wavelength.3.2.13 UV-C, nradiation within the ultraviolet spectrumw
24、hich extends from approximately 100 to 280 nm in wave-length.3.2.14 xenon arc lamp, na specialized type of gas dis-charge lamp, an electric light that produces light by passingelectricity through ionized xenon gas at high pressure.4. Summary of Practice4.1 This practice describes the steps required
25、to depositmicroorganisms onto carriers.4.2 This practice defines the process for adding soilingagents on top of microorganisms, which can reduce theeffectiveness of UV antimicrobial activity.4.3 This practice defines a protocol for quantifying the dosea UVGI device delivers to a surface.4.4 This pra
26、ctice defines the process for exposure of micro-organisms to UVGI.4.5 This practice defines protocols for extraction of viablemicrobes from carriers followed by enumeration.5. Significance and Use5.1 This practice determines the effectiveness of UVGIdevices for reducing viable microorganisms deposit
27、ed oncarriers.5.2 This practice evaluates the effect soiling agents have onUVGI antimicrobial effectiveness.5.3 This practice determines the delivered UVGI dose.6. Hazards6.1 UV light becomes increasingly hazardous as the wave-length decreases, shifting from longer wavelengths (UV-A,UV-B) to shorter
28、 wavelengths (UV-C). UV-A and UV-B arepart of the normal solar spectrum found in our atmosphere andare responsible for UV-related aging, sunburns, and mutageniceffects. UV-C radiation is filtered out by the Earths atmosphereand is not part of the received solar spectrum. UV-C is highlymutagenic and
29、is harmful to all life forms.NOTE 1This practice is not designed to evaluate safety concernssurrounding UV exposure.6.2 Some UVGI bulbs produce ozone, which is harmful toall life forms. Consult the manufacturer of the UVGI bulbs orthe device, or both, to determine if ozone is produced. If so,you mus
30、t follow Occupational Safety and Health Administra-tion (OSHA) regulations to ensure worker safety.NOTE 2This practice is not designed to evaluate safety concernssurrounding ozone production by UVGI devices.6.3 Safety measures are required to ensure workers are notexposed to UV light during testing,
31、 especially UV-B andUV-C. Safety glasses with appropriate UV protection andappropriate lab attire shall be used at all times when workingwith UV devices.6.4 Signage shall be posted on the laboratory when UVlights are in use to prevent accidental exposure to coworkers.7. Reagents and Materials57.1 Mi
32、croorganismsselected by user based on the overallapplication.4Available from AOAC International, 2275 Research Blvd., Suite 300,Rockville, MD 20850-3250, http:/www.aoac.org.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the
33、testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.E3135 1827.2 Soiling Agentsselected by user
34、based on the overallapplication.7.3 50-mL Centrifuge Tubessterile, with caps.7.4 Growth Media and Supplemental Reagentsselected byuser based on the overall application.7.5 Cell Spreadersdisposable, plastic triangular 60mm,sterile.7.6 Petri Dishes100 15 mm, sterile; glass or plastic.7.7 Carriers2.5 c
35、m in diameter composed of any material.8. Equipment8.1 UV Exposure DeviceUVGI light source that is astandalone bulb or contained within an exposure system.8.2 Radiometercalibrated to measure 254-nm irradiationin accordance with Test Method G130 or ISO 9370.8.3 Spectrophotometercalibrated to measure
36、wavelengthsranging from at least 200 315 nm. Typically, a cosinecorrector is used that will allow light to be collected from 180field of view.8.4 Vortex Mixer.8.5 Thermometer or Thermocoupleaccuracy of 60.5 Cand range of 10 100 C.8.6 Hygrometeraccuracy of 65% RH and a range of 1 99 % RH.8.7 Analytic
37、al Balancecapable of weighing 0.001 g and arange of up to 500 g.8.8 Refrigeratorcapable of maintaining28C.8.9 Electronic Timer.8.10 Autoclave (steam)capable of maintaining 121 123C and 103 117 kPa.8.11 Pipettorcapable of a volume up to 1 mL and aprecision of 0.001 mL.8.12 Incubatoraccuracy of 62 C.8
38、.13 Biological Safety CabinetClass II, A2.9. UV Dose Determination9.1 Turn on the UVGI light source and allow it to stabilizeas indicated by the manufacturer.9.2 Measure and record air temperature and humidity in theUV exposure device. If the UVGI light source is unshielded,measure and record air te
39、mperature and humidity in the room.NOTE 3Some UVGI light sources will generate heat during operation.The delivered dose of UV light can be reduced due to elevated tempera-ture. It is important to quantify changes in air temperature over the courseof the exposure and measure the effect it has on UVGI
40、 dose.NOTE 4The delivered dose of UVGI light can be reduced due toelevated relative humidity. It is important to quantify humidity over thecourse of the exposure and measure the effect it has on UVGI dose.9.3 Measure output from mercury vapor or LED UVGI lightusing a calibrated radiometer. If using
41、a xenon arc lamp, referto 9.4.9.3.1 Radiometers are normally set to measure a band ofwavelengths surrounding the peak intensity wavelength, whichwill vary among manufacturers.9.3.2 The peak intensity for UV-C is 254 nm, and thiswavelength should be used as the reference point for UVoutput from the U
42、VGI light source and for measurement withthe radiometer.9.3.3 The irradiance is measured at the distance the carrierwill be positioned away from the UVGI light source.9.3.3.1 The irradiance measured by most radiometers isgenerally provided in power per square centimeter.9.3.3.2 Irradiance is represe
43、nted as a unit of watts (forexample, microwatt, milliwatt, etc.) resulting in a unit descrip-tion of xW/cm2.9.3.3.3 Delivered dose is a function of irradiance and time,which is expressed as J/cm2(W/cm2 Time (seconds ofexposure).9.3.3.4 Final dose should be expressed in J/cm2.NOTE 5The intensity of U
44、VGI will vary significantly over the lengthof the bulb, with the highest irradiance being generated from the center ofthe bulb. Therefore, UV output must be defined at the distance along thelength of the UVGI light source where the carrier will be positioned.NOTE 6UVGI bulbs have a finite service li
45、fe and delivered UV outputwill diminish with use. It is important to quantify the UVGI dose deliveredfor each experiment and not rely on historical measurements or manufac-turer dose information.9.4 Measure irradiance from the xenon arc lamp using aspectrophotometer fitted with a cosine corrector se
46、t to measureall wave lengths ranging from 200 320 nm.NOTE 7Xenon lamps are different from mercury vapor or LED bulbsbecause they produce UVGI irradiation over a wider array of wavelengths.Thus, measurement at a single wave length is not adequate to understandtotal dose.9.4.1 Follow guidance provided
47、 by the spectrophotometermanufacturer to ensure the spectrophotometer is properlycalibrated and set up to measure UVGI doses.9.4.2 The irradiance is measured at the distance the carrierwill be positioned away from the UVGI light source.9.4.3 The irradiance provided by the spectrophotometer willbe in
48、 the same units described in 9.3, but a value will beprovided for each wavelength.9.4.4 Final dose for each wavelength should be expressed inJ/cm2.NOTE 8The dose for all wavelengths can be summed to determine anoverall exposure dose. However, all wavelengths do not have equivalentmicrobicidal activi
49、ty, and thus comparison of the summed dose to otherdevices and products may not be meaningful.10. Test Procedure10.1 Prepare microorganisms using standard microbiologi-cal practices.10.1.1 For viral studies, reference Test Method E1053,Section 8.10.1.2 For bacterial and fungal studies, reference AOAC961.02 section A(b)NOTE 9Impurities in the media and intrinsic organic load act assoiling agents and reduce the microbicidal effectiveness of the UVGIdevice.10.2 Prepare round carriers that are 2.5 cm in diameter.
