1、Designation: D7855/D7855M 13Standard 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 immediately following the
2、 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 test method covers a
3、n 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 so it can be easil
4、y 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 duringinstallation in a
5、n 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 evaluation ofsurfaces des
6、igned 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 as standard. The
7、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 any, associated wi
8、th its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D16 Terminology for Paint, Related Coatings, Materials, andApplica
9、tionsD1193 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 inASTM Test MethodsE691 Practice for Conducting an Interl
10、aboratory 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 appro-priate agar to demonstrate viability of fungal organis
11、ms 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 thin layer onto a building fabric.3.2.3 interior, nany surf
12、ace not exposed to exterior envi-ronments in end use.3.2.4 interior finish, ninterior wall and ceiling finish andinterior floor finish.3.2.5 material control, nuntreated representative sub-strate.3.2.6 sample, na portion of material taken from a largerquantity for the purpose of estimating propertie
13、s or composi-tion of the larger quantity.3.2.7 sample tests, na group of samples (one or more).1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.28 on Biodeterioration.Curren
14、t edition approved Oct. 1, 2013. Published November 2013. DOI:10.1520/D7855_D7855M13.2For 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
15、page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.8 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
16、 unit needed toobtain a single test determination.4. Summary of Test Method4.1 This test method is an indirect inoculation to a coatedinterior building product of two fungal organisms, Aspergillusniger and Penicillium citrinum. Test specimens are placed in anenvironmental chamber maintained at 30 6
17、2C 86 6 3.6Fand at greater than 90 % relative humidity for four weeks.Humidity is maintained by adding sufficient sterile DI water tothe bottom of the covered test chamber. A continuous fungalinoculation is provided by open Petri dishes supporting sevenday cultures of the two test organisms placed o
18、n a rack belowthe test pieces. Test specimens are removed from the chamberafter four weeks exposure and examined for fungal growth.The evaluation is a macroscopic inspection of the test pieceswith indirect lighting.5. Significance and Use5.1 An accelerated test for determining the resistance ofinter
19、ior coated building products to mold growth is useful inestimating the relative performance for use in interior environ-ments under conditions favorable to fungal growth.5.2 Static or environmental chambers provide controlledlaboratory micro-environment conditions. These chambers arenot intended to
20、duplicate room conditions, and care must betaken when interpreting the results. Static chambers are not asubstitute for dynamic chambers or field studies.6. Interferences6.1 Proper lab ventilation, hygiene, and aseptic techniquemust be followed to ensure fungal cultures are pure and nocross contamin
21、ation of fungal strains or growth media occurs.6.2 The exposure of test specimens to environmental con-ditions including temperature, humidity, and light can impacttest results. To minimize variability of test results consistenthandling and storage of test specimens is important.7. Apparatus7.1 Envi
22、ronmental ChamberA non-corrosive covered boxcontaining standing water placed in an incubator at 30 6 2C86 6 3.6F will expose the test specimens to a controlledenvironment of temperature and humidity. Containers foundsuitable include glass, polycarbonate3or other plastic storagecontainers which are g
23、enerally available. For example anineteen liter container measuring approximately 460 mm longby 300 mm wide by 230 mm high 18 in. long by 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 p
24、ort that permitsobservation of chamber controls. Chamber shall permit tem-perature and humidity monitoring without opening the cham-ber 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 o
25、nto the testspecimens. For stand-alone chambers, this can be accom-plished by designing the top so that the interior surface is at anangle 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 polycarbona
26、te attached to theunderside of the lid will direct the condensation away from thetest samples. Condensation inside the test chamber is not 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 sup
27、porting 100 by 15mm 4 by58 in. sterile Petri dishes alternating the two fungalorganisms. See Fig. 1 for non-corroding open grid example.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 s
28、pecimens by suspending them fromrods using plastic cable ties. Samples must be 50 to 100 mm 2to 4 in. above the inoculated Petri dishes. 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 ra
29、cks shall be non-corroding and of sufficient strength to support specimensthroughout the duration of the test. Use of engineered plasticssuch 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
30、 rods.7.2 Measurement Instruments, capable of accurate and pre-cise measures of temperature and humidity. See Section 12.7.3 Incubator or Controlled Temperature Room maintainedat 30 6 2C 86 6 3.6F.3The 5.0 Gallon Rectangular Food Storage Containers from various suppliershave been found to work well.
31、FIG. 1 Non-corroding Open Grid for Placement in Bottom of theEnvironmental ChamberD7855/D7855M 1328. Reagents and Materials8.1 CulturesAspergillus niger, ATCC46275 or IMI/CABIBioscience545551, Penicillium citrinum ATCC 9849 or IMI/CABI Bioscience 321326.8.1.1 Selection of the appropriate test organi
32、sms is ex-tremely important and must be representative of the types oforganisms found or likely to be found on the interior coatedbuilding products being tested. The organisms named in 8.1 arenot representative of all potential fungal organisms that may befound growing on interior coated building pr
33、oducts. Otherfungal organisms may also be used in separate evaluations, butthe specified organisms in 8.1 shall be used and reported. Thepotential for interferences between non-specified fungal testorganisms shall be considered when using organisms otherthan those named in 8.1.NOTE 1Subcommittee D01
34、.28 reviewed the published study listed inthe Reference section of this document and determined the organisms in8.1 as appropriate.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
35、 ReagentsWater shall be distilled water orhigher purity. See Specification D1193.8.5 Sabouraud Dextrose Agar or media appropriate 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 indiv
36、iduals inlaboratories specially equipped for conducting microbiologicaltests.10. Sampling and Test Specimens10.1 Sampling shall be 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
37、to be evaluated.The number of test specimens will be reported in the results.10.2.2 Additional replicates should be available to 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
38、to the bottomof the container. Ensure the water level is sufficient to providehumidity through the duration of the test. If the test 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
39、 duration of the test. Thewater level should be at least 25 mm 1 in. below the racksupporting the Petri dishes of the fungal test 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 lo
40、ggerinto the environmental chamber and set in an incubator or othertemperature controlled chamber set at 30 6 2C 86 6 3.6Fto equilibrate 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
41、 in 4.1, results shall be discarded and testing restarted withnew test pieces. Temperature and humidity measurements shallbe included 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
42、.1 may not occur at the same rate.Penicillium citrinum typically takes longer to sporulate thanAspergillus niger so cultivation should 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
43、 to 50F.11.3.1 To prepare the inoculum, dislodge fungal spores fromagar by rolling a sterile cotton-tipped swab moistened withsterile distilled water across the sporulating fungi. Transfer thespores from the cotton tipped swab to a test tube containing 54Cultures can be obtained from American Type C
44、ulture 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 Set UpFIG. 3 Cable Ties used to Hang Test Spe
45、cimens from Rods Insideof the Environmental ChamberD7855/D7855M 133ml of sterile distilled water and a nontoxic wetting agent 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 eac
46、h fungalorganism used.11.4 Pour 25 mL 1.0 oz. of Sabouraud Dextrose orappropriate agar for test organisms named in 8.1 into 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. F
47、or 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 3
48、0C 82 to 86F for 7 to 14 days or untildense sporulating fungal growth is present. Prepare an equalnumber of Petri dishes for both test organisms in sufficientquantity to cover the rack placed at the bottom of theenvironmental chamber.11.6 If growth is sparse or absent after 14 days, preparefresh ino
49、culums as discussed in 11.3 and repeat inoculation ofnew agar plates.11.7 Place the sporulating agar plates on the rack of theequilibrated environmental chamber referenced in 11.2 andremove covers. Place Petri dishes alternating between the twotest organisms to ensure equal exposure of the test specimensto both fungal strains. Fig. 4 shows the alternating pattern ofagar plates on the rack at the bottom of the environmentalchamber.12. Calibration and Standardization12.1 Instruments for temperature measurement shall me
