1、Designation: D7855/D7855M 13 (Reapproved 2017)Standard Test Method forDetermination of Mold Growth on Coated Building ProductsDesigned for Interior Applications Using an EnvironmentalChamber and Indirect Inoculation1This standard is issued under the fixed designation D7855/D7855M; the number immedia
2、tely following the designation indicates theyear of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This te
3、st method covers an environmental chamber andthe conditions of operation to evaluate in a 4-week period therelative resistance to mold growth and microbial surfacedefacement on coated building products designed for interiorapplication using an indirect inoculation method. The appara-tus is designed
4、so it can be easily built or obtained by anyinterested party.1.2 This test method can be used to evaluate the compara-tive resistance of coated building products to accelerated moldgrowth. Ratings do not imply a specific time period that thecoated building product will be free of fungal growth durin
5、ginstallation in an interior environment.1.3 This test method is not intended for use in the evaluationof public health claims.1.4 The test method is intended for the accelerated evalua-tion of mold growth on a coated building product designed forinterior use. This method is not intended for evaluat
6、ion ofsurfaces designed for exterior applications or uncoated sur-faces. Use of this test method for evaluating exterior perfor-mance has not been validated, nor have the limitations for suchuse been determined.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately
7、 as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.6 This standard does not purport to address all of thesafety concerns, if
8、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.1.7 This international standard was developed in accor-dance with internati
9、onally 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) Committee.2. Referenced Documents2.1 ASTM Standards:2D16 Termi
10、nology for Paint, Related Coatings, Materials, andApplicationsD1193 Specification for Reagent WaterD6329 Guide for Developing Methodology for Evaluatingthe Ability of Indoor Materials to Support MicrobialGrowth Using Static Environmental ChambersE177 Practice for Use of the Terms Precision and Bias
11、inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 DefinitionsFor definitions of terms refer to Terminol-ogy D16.3.2 Definitions of Terms Specific to This Standard:3.2.1 chamber control, nopen Petri dish containing app
12、ro-priate agar to demonstrate viability of fungal organisms withinthe environmental chamber.3.2.2 coated building product, na building material hav-ing a liquid, liquefiable or mastic composition that is convertedto a solid protective, decorative, or functional adherent filmafter application as a th
13、in layer onto a building fabric.3.2.3 interior, nany surface not exposed to exterior envi-ronments in end use.3.2.4 interior finish, ninterior wall and ceiling finish andinterior floor finish.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, a
14、nd Applications and is the direct responsibility ofSubcommittee D01.28 on Biodeterioration.Current edition approved Dec. 1, 2017. Published December 2017. Originallyapproved in 2013. Last previous edition approved in 2013 as D7855/D7855M-13.DOI: 10.1520/D7855_D7855M13R17.2For referenced ASTM standar
15、ds, 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 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1
16、9428-2959. 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 Recommendations issued by the World Trade Organization Tec
17、hnical Barriers to Trade (TBT) Committee.13.2.5 material control, nuntreated representative sub-strate.3.2.6 sample, na portion of material taken from a largerquantity for the purpose of estimating properties or composi-tion of the larger quantity.3.2.7 sample tests, na group of samples (one or more
18、).3.2.8 test run, nthe evaluation of coated building productsin accordance with the procedure outlined in this test method.3.2.9 test specimen, na portion of a test unit needed toobtain a single test determination.4. Summary of Test Method4.1 This test method is an indirect inoculation to a coatedin
19、terior building product of two fungal organisms, Aspergillusniger and Penicillium citrinum. Test specimens are placed in anenvironmental chamber maintained at 30 6 2C 86 6 3.6Fand at greater than 90 % relative humidity for four weeks.Humidity is maintained by adding sufficient sterile DI water tothe
20、 bottom of the covered test chamber. A continuous fungalinoculation is provided by open Petri dishes supporting sevenday cultures of the two test organisms placed on a rack belowthe test pieces. Test specimens are removed from the chamberafter four weeks exposure and examined for fungal growth.The e
21、valuation is a macroscopic inspection of the test pieceswith indirect lighting.5. Significance and Use5.1 An accelerated test for determining the resistance ofinterior coated building products to mold growth is useful inestimating the relative performance for use in interior environ-ments under cond
22、itions favorable to fungal growth.5.2 Static or environmental chambers provide controlledlaboratory micro-environment conditions. These chambers arenot intended to duplicate room conditions, and care must betaken when interpreting the results. Static chambers are not asubstitute for dynamic chambers
23、 or field studies.6. Interferences6.1 Proper lab ventilation, hygiene, and aseptic techniquemust be followed to ensure fungal cultures are pure and nocross contamination of fungal strains or growth media occurs.6.2 The exposure of test specimens to environmental con-ditions including temperature, hu
24、midity, and light can impacttest results. To minimize variability of test results consistenthandling and storage of test specimens is important.7. Apparatus7.1 Environmental ChamberA non-corrosive covered boxcontaining standing water placed in an incubator at 30 6 2C86 6 3.6F will expose the test sp
25、ecimens to a controlledenvironment of temperature and humidity. Containers foundsuitable include glass, polycarbonate3or other plastic storagecontainers which are generally available. For example anineteen liter container measuring approximately 460 mm longby 300 mm wide by 230 mm high 18 in. long b
26、y 12 in. wideby 9 in. high can accommodate fifteen 75 by 100 mm 3 by 4in. test specimens suspended from rods using cable ties.Opaque chambers shall have a viewing port that permitsobservation of chamber controls. Chamber shall permit tem-perature and humidity monitoring without opening the cham-ber
27、lid. Examples would include wireless or wired probes.7.1.1 The test chamber shall be designed so that no conden-sate forming on the top interior surface will drip onto the testspecimens. For stand-alone chambers, this can be accom-plished by designing the top so that the interior surface is at anang
28、le of at least 30 degrees, relative to the plane of the bottomof the chamber. A sheet of polycarbonate secured at an angle,or hinged or joined sheets of polycarbonate attached to theunderside of the lid will direct the condensation away from thetest samples. Condensation inside the test chamber is n
29、ot aconcern as it indicates that humidity is being maintained.7.1.1.1 A non-corrosive open grid is placed at the bottom ofthe test chamber above the water level supporting 100 by 15mm 4 by58 in. sterile Petri dishes alternating the two fungalorganisms. See Fig. 1 for non-corroding open grid example.
30、Place sufficient Petri dishes on the rack to fill the grid. Theplastic grid designed to cover recessed ceiling fixtures orsimilar works well.7.1.1.2 Position test specimens by suspending them fromrods using plastic cable ties. Samples must be 50 to 100 mm 2to 4 in. above the inoculated Petri dishes.
31、 The minimumdistance between adjacent specimens and between test speci-mens and chamber walls shall be at least 25 mm 1 in.Materials used as the rods or mounting racks shall be non-corroding and of sufficient strength to support specimensthroughout the duration of the test. Use of engineered plastic
32、ssuch as polycarbonate has been found suitable. Fig. 2 shows aphoto of typical chamber construction. Fig. 3 illustrates use ofcable ties to hang test specimens from rods.7.2 Measurement Instruments, capable of accurate and pre-cise measures of temperature and humidity. See Section 12.3The 5.0 Gallon
33、 Rectangular Food Storage Containers from various suppliershave been found to work well.FIG. 1 Non-corroding Open Grid for Placement in Bottom of theEnvironmental ChamberD7855/D7855M 13 (2017)27.3 Incubator or Controlled Temperature Room maintainedat 30 6 2C 86 6 3.6F.8. Reagents and Materials8.1 Cu
34、lturesAspergillus niger, ATCC46275 or IMI/CABIBioscience545551, Penicillium citrinum ATCC 9849 or IMI/CABI Bioscience 321326.8.1.1 Selection of the appropriate test organisms is ex-tremely important and must be representative of the types oforganisms found or likely to be found on the interior coate
35、dbuilding products being tested. The organisms named in 8.1 arenot representative of all potential fungal organisms that may befound growing on interior coated building products. Otherfungal organisms may also be used in separate evaluations, butthe specified organisms in 8.1 shall be used and repor
36、ted. Thepotential for interferences between non-specified fungal testorganisms shall be considered when using organisms otherthan those named in 8.1.NOTE 1Subcommittee D01.28 reviewed the published study listed inthe Reference section of this document and determined the organisms in8.1 as appropriat
37、e.8.2 Chamber ControlsOpen PDA plates placed on thebottom of the chamber at opposite corners and near the center.8.3 Material Controls, if available, see 3.2.8.4 Purity of ReagentsWater shall be distilled water orhigher purity. See Specification D1193.8.5 Sabouraud Dextrose Agar or media appropriate
38、 forfungi selected.8.6 Sterile Disposable Cotton-tipped Swabs.8.7 Sterile 100 by 15 mm (4 by58 in.) Petri Dishes.9. Hazards9.1 This test must be performed by trained individuals inlaboratories specially equipped for conducting microbiologicaltests.10. Sampling and Test Specimens10.1 Sampling shall b
39、e representative of the product beingevaluated.10.2 Test Specimens:10.2.1 A minimum of three test specimens shall be cut fromeach sampled coated interior building product to be evaluated.The number of test specimens will be reported in the results.10.2.2 Additional replicates should be available to
40、rerun thetest if necessary.11. Preparation of Apparatus and Inoculum11.1 Clean and sanitize the environmental chambers prior touse. Add approximately 25 mm 1 in. of water to the bottomof the container. Ensure the water level is sufficient to providehumidity through the duration of the test. If the t
41、est specimensabsorb the water or water is lost through the seal of the lid,additional water must be added to ensure the relative humidityremains at 90 % or greater for the duration of the test. Thewater level should be at least 25 mm 1 in. below the racksupporting the Petri dishes of the fungal test
42、 organisms.NOTE 2Petroleum jelly or similar product may be used between thelid and the container to improve the seal.11.2 Insert the temperature/humidity sensor or data loggerinto the environmental chamber and set in an incubator or othertemperature controlled chamber set at 30 6 2C 86 6 3.6Fto equi
43、librate for 24 h before starting the test. Record thetemperature and humidity not less than every 7 days. Iftemperature and humidity readings are outside the parametersset in 4.1, results shall be discarded and testing restarted withnew test pieces. Temperature and humidity measurements shallbe incl
44、uded in the final report.11.3 Prepare spore suspensions of each test fungi from 7 to14 day old well sporulating cultures. Maturation of the fungalorganisms designated in 8.1 may not occur at the same rate.Penicillium citrinum typically takes longer to sporulate thanAspergillus niger so cultivation s
45、hould begin earlier assuringboth organisms are sporulating when placed in the environ-mental chamber. Stock cultures may be kept for no more thanfour months at 3 to 10C 37 to 50F.11.3.1 To prepare the inoculum, dislodge fungal spores fromagar by rolling a sterile cotton-tipped swab moistened with4Cu
46、ltures can be obtained from American Type Culture Collection, P.O. Box1549, Manassass, VA 20108 or Mycological Services, P.O. Box 1056,Crawfordsville, IN 47933.5Cultures can be obtained from IMI/CABI Bioscience, Nosworthy Way,Wallingford, Oxfordshire, OX108DE UK.FIG. 2 Typical Environment Chamber Se
47、t UpFIG. 3 Cable Ties used to Hang Test Specimens from Rods Insideof the Environmental ChamberD7855/D7855M 13 (2017)3sterile distilled water across the sporulating fungi. Transfer thespores from the cotton tipped swab to a test tube containing 5ml of sterile distilled water and a nontoxic wetting ag
48、ent foreach test organism. Blend the fungal spore suspension on thevortex mixer for 10 s to liberate spores from hyphae and tobreak up spore clumps. Repeat this procedure for each fungalorganism used.11.4 Pour 25 mL 1.0 oz. of Sabouraud Dextrose orappropriate agar for test organisms named in 8.1 int
49、o 100 by 15mm 4 by58 in. sterile Petri dishes and allow the agar tosolidify. Prepare sufficient Petri dishes to fill the rack placed atthe bottom of each environmental chamber. For the chambersize referenced in 7.1, twelve 100 by 15 mm 4 by58 in. Petridishes are appropriate.11.5 Transfer 200 to 300 L (microlitres) of a single sporesuspension to each Petri dish. Spread the inoculum across thesurface of the agar with a cell spreader or equivalent, cover andincubate at 28 to 30C 82 to 86F for 7 to 14 days or untildense
