1、Designation: D8068 18Standard Practice forCollection of Culturable Airborne Fungi or Bacteria on AgarPlates by Inertial Impaction Systems1This standard is issued under the fixed designation D8068; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 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.INTRODUCTIONThis practice was introduced to bring uniformity to the process of sample collection for cul
3、turablefungi or bacteria using inertial impaction samplers for analysis by culture and optical microscopy.1. Scope1.1 The purpose of this practice is to describe procedures forthe collection of culturable airborne fungal spores or fragmentsor bacteria on agar plates using inertial impaction sampling
4、techniques.1.2 This practice does not include collection of culturablefungi or bacteria by devices not using agar plates.1.3 This practice presumes that the user has a fundamentalunderstanding of field investigative techniques related to thescientific process, and sampling plan development and imple
5、-mentation. It is important to establish the related hypothesis tobe tested and the supporting analytical methodology needed inorder to identify the sampling media to be used and thelaboratory conditions for analysis.1.4 This practice does not address the development of aformal hypothesis or the est
6、ablishment of appropriate anddefensible investigation and sampling objectives. It is pre-sumed the investigator has the experience and knowledge baseto address these issues.1.5 This practice does not provide the user sufficient infor-mation to allow for interpretation of the analytical results froms
7、ample collection. It is the users responsibility to seek orobtain the information and knowledge necessary to interpretthe sample results reported by the laboratory.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.7 This sta
8、ndard 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.8 This in
9、ternational standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT
10、) Committee.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD6044 Guide for Representative Sampling for Managementof Waste and Contaminated MediaD3195/D3195M Practice for Rotameter CalibrationE2589 Terminology Relating to Nonsieving Methods
11、 ofPowder CharacterizationF1671 Test Method for Resistance of Materials Used inProtective Clothing to Penetration by Blood-Borne Patho-gens Using Phi-X174 Bacteriophage Penetration as a TestSystem3. Terminology3.1 DefinitionsFor definitions of terms used in thispractice, see Terminology D1356.3.1.1
12、agar, na semisolid culture medium used to supportthe growth of bacteria and other micro-organisms. F16713.1.2 sample, na portion of a population.3.1.2.1 DiscussionA portion of material that is taken fortesting or record purposes. D60443.1.3 sample, representative, na sample collected in sucha manner
13、 that it reflects the characteristics of interest of a1This practice is under the jurisdiction of ASTM Committee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.08 on Assessment, Sampling,and Analysis of Microorganisms.Current edition approved Nov. 1, 2018. Published November
14、2018. DOI:10.1520/D8068-18.2For 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.Copyright ASTM International, 100
15、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Rec
16、ommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1population (as defined) from which it is collected.adapted from D60443.1.3.1 DiscussionA population in the context of thisstandard refers to culturable fungi- or bacteria colony-formingunits that exist a
17、t the time and location of sampling.3.1.4 sampling train, nthe assemblage of equipment nec-essary to sample atmospheres. D13563.1.4.1 DiscussionComplete assembly from the pumpsystem through to the agar plate including any transport tubingand connectors.3.2 Definitions of Terms Specific to This Stand
18、ard:3.2.1 aerodynamic diameter (da), nthe diameter of a unitdensity sphere that has the same inertial properties as theparticle under analysis under the same conditions. E2589 093.2.1.1 DiscussionFor fungal spores, this is generallybased on a water droplet (spherical particle) having a density of1 g
19、/cm3. Aerodynamic diameter has been developed to catego-rize the sizes of particles of different shapes and densities witha single dimension. The aerodynamic diameter is not necessar-ily equal to the physical diameter due to variations in shape ordensity.3.2.2 bacteria, nany of a class of microscopi
20、c prokaryoticorganisms reproducing by fission or by spores.3.2.3 chain of custody (COC), na document that providesfor the traceable transfer of field samples to the analyticallaboratory.3.2.3.1 DiscussionThe COC may or may not be combinedwith the Field Data Sheet.3.2.4 fungus (s), fungi (pl), neukar
21、yotic, heterotrophic,absorptive organisms that usually develop a rather diffuse,branched, tubular body (that is, network of hyphae) and usuallyreproduce by means of spores. adapted from Kendrick33.2.4.1 DiscussionThe terms mold and mildew arefrequently used by laypersons when referring to various fu
22、ngalcolonization.3.2.5 inertial impactor, na device designed for the collec-tion of particles that are separated from the air stream by inertiato force the impact onto an adhesive surface.3.2.5.1 DiscussionInertial impactors are available inmany designs and include both multi-orifice (also known asm
23、ultiple-hole or sieve plate) and slit to agar (also knownas rotating slit) samplers.4. Significance and Use4.1 This practice is intended for the collection of airborneparticles on agar plates using inertial impaction for the purposeof culturing fungi or bacteria.4.2 This practice is valuable when sp
24、ecies level identifica-tion or quantity of culturable aerosolized fungi and bacteria areimportant factors for the indoor air quality investigation.4.3 It is the responsibility of the user to assure that they arein compliance with all local, state, and federal regulationsgoverning the inspection of b
25、uildings for fungal colonizationand the collection of associated samples.4.4 This practice is intended to provide the user with a basicunderstanding of the equipment, materials, and instructionsnecessary to effectively collect air samples on agar plates usingan inertial impactor.4.5 This practice is
26、 intended to minimize systematic sam-pling variations between different data sets.5. Preparation of Sampling Equipment5.1 Equipment List:5.1.1 Sampling TrainThe combination of componentsfrom the pump or fan system through to the agar plateincluding any transport tubing, flow controller, and connecto
27、rs.The configuration may be an integrated assembly or compo-nents that have been configured with an external pump.NOTE 1Rotary vane, diaphragm, linear magnetic, piston, and fandriven devices may have the open flow capacity for specific impactors;however, resistance to flow through the impactor can d
28、ramatically reduceflow rates. Care must be taken to select a pump and calibrator that arecompatible with impactors to set and measure flow rates properly.5.1.1.1 For external pump assemblies, use flexible tubingand connectors appropriate for secure connection of impactorto pump.5.1.2 Primary flow ra
29、te standard, with a measuring rangeappropriate for the system and with a 65 % tolerance of thedesired flow rate.5.1.3 Secondary Flow Rate StandardRotameter or otherdevice used to check system performance in the field.5.1.4 Stop watch, or other timing device capable of measur-ing time in increments o
30、f minutes and seconds (1 secondresolution).5.1.5 Field Data SheetRefer to 6.6.5.1.6 Agar plate.5.1.7 Support stand (optional), for consistent sample collec-tion height.5.1.8 70 % isopropanol technical grade or better.5.1.9 Single use gloves to prevent contamination duringsampling.5.2 Calibration:5.2
31、.1 Calibrate or verify airflow through the assemblyconfiguration that will be used in the field. For example, do notcalibrate with one length of tubing and sample with a differentlength of tubing.5.2.2 Use a primary or secondary flow rate standard toverify the airflow rate passing through the sampli
32、ng assembly.Be aware that it is the airflow rate through the impactor, not thepump or fan that shall be calibrated.5.2.3 Verify the secondary flow rate standard using a pri-mary flow rate standard in accordance with the manufacturersrecommendations.5.2.4 Integrated sampling assemblies may not be cap
33、able ofbeing calibrated by the user. Follow manufacturers instruc-tions when user calibration is not possible.5.2.5 Verify and record the airflow prior to and followingfield sampling. If the result of the post-field verification checkis greater than 610 % of pre-field verification, either (1)discard
34、 any samples collected, re-adjust the sampler asnecessary, and re-sample; or (2) note any airflow rate variations3Kendrick, B., The Fifth Kingdom, Focus Publishing / R. Pullins and Co, 2008.D8068 182in the field notes and any data interpreting documents, record-ing the magnitude of the change and av
35、eraging the airflow rates(Practice D3195/D3195M). Use the average airflow rate tocalculate sample volume.6. Sample Collection6.1 Preliminary Considerations:6.1.1 Inspect the agar plate and discard any that aredamaged, expired or compromised. Allow agar plates toequilibrate to ambient temperature bef
36、ore sampling.6.2 Sample Position and Conditions:6.2.1 Position inertial impactor to allow the free flow of airaround it.6.2.2 Record sampling conditions including time, date, andlocation. If relevant, record other conditions such as;temperature, relative humidity, air movement (i.e. wind, fans,HVAC)
37、, height above ground and occupant activity duringsample collection.6.3 Sampling Time and Sample Flow Rate:6.3.1 Follow manufacturersrecommendations for samplingtime, sample volume, and flow rate.NOTE 2Manufacturers recommendations may incorporate a range insampling time, sample volume, or flow rate
38、. When a range exists in anyof these parameters, the sampling plan objectives shall determine thespecific value within the range to be used.NOTE 3Caution should be taken not to dry out the agar duringsampling.6.3.2 Record the sampling time in minutes and seconds,sample volume in litres, and flow rat
39、e in litres per minute.6.4 Sample Labeling:6.4.1 Label each sample with a unique identifier.6.4.2 Record the type, lot number of the agar plate andexpiration date.NOTE 4Using agar media of a given type, from multiple productionlots should be avoided. Differences between or among production lots cani
40、ntroduce a source of variation to the test data.6.4.3 Record sample unique identifier on a field sheet,logbook, COC record, or a combination of these.6.5 Sample Orientation:6.5.1 Follow manufacturers recommendations.6.6 Field Data Sheet:6.6.1 Record the following on the field data sheet:6.6.1.1 Samp
41、ling date;6.6.1.2 Project name and project location(s);6.6.1.3 Investigators name(s);6.6.1.4 Type of sampling assembly;(1) Assembly pump or fan identifier may be appropriate.6.6.1.5 Pre- and post-verification data, if applicable;6.6.1.6 Unique sample identifiers;6.6.1.7 Sample locations6.6.1.8 Sampl
42、ed air flow rate;6.6.1.9 Sample start time;6.6.1.10 Sample stop time or duration;6.6.1.11 Calculated sample volume; and6.6.1.12 Environmental sampling conditions (refer to 6.2.2).6.7 Sampling Assembly Operation:6.7.1 Prepare the sampling assembly wearing single usegloves.6.7.2 Clean surface of sampl
43、ing assembly air intake areawith 70 % isopropanol or equivalent and let it dry before eachagar plate is situated to minimize contamination.6.7.3 Remove and maintain control of the protective coverfor the agar plate and install agar plate in the samplingassembly. Take precaution to minimize contamina
44、tion of thecover and the agar. For example, when cover is removed leaveit open side down.6.7.4 Minimize influence on the sample collection fromoperator proximity to the sample inlet.6.7.5 Start pump or fan and record start time or durationwhere operation is on a timer.NOTE 5Use of timers may be help
45、ful when operating multiple pumpssimultaneously.6.7.6 After sampling, turn pump or fan off and record stoptime.6.7.7 Replace the protective cover and remove from system.Seal the agar plate to prevent contamination.6.7.8 Place samples in an insulated container and defer tolaboratory recommendations f
46、or packing and temperature con-trol.6.8 Sample Submittal for Analysis:6.8.1 Submit samples for analysis with COC.6.8.2 The COC includes:6.8.2.1 Name and signature of investigator;6.8.2.2 Date, time, and signature of releasing party;6.8.2.3 Name and contact information of responsible party(that is, i
47、nvestigators employer);6.8.2.4 Project identification (that is, project identifier orsite location); and6.8.2.5 List of all samples being submitted.6.8.3 Communicate the following analytical request infor-mation:6.8.3.1 Contact information for analytical report receipt, ifdifferent than submitters i
48、nformation;6.8.3.2 Analytical method requested;6.8.3.3 Type of agar plate submitted;6.8.3.4 Incubation temperature, if different from the labora-tory standard procedure;6.8.3.5 Sample volume or sample time and flow rate; and6.8.3.6 Special or unique instructions, if applicable.6.8.4 Sample transport
49、 for analysis.6.8.4.1 Transport samples in an insulated container. Thesamples should reach the laboratory within 24 hours ofcollection. Samples should be packed for transport with theexposed agar side up.6.8.4.2 Protect samples from damage and temperature ex-tremes.6.8.4.3 Ship samples with a trackable carrier or hand de-liver.D8068 1837. Interferences and Limitations7.1 The investigator must understand the purpose of theproject and consider interferences and limitations. Factors thatinfluence variation in sample collection include, but
