ASTM_D_3273_-_21.pdf

Designation:D327321Standard Test Method forResistance to Growth of Mold on the Surface of InteriorCoatings in an Environmental Chamber1This standard is issued under the fixed designation D3273;the number immediately following the 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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method describes the use of an environmentalchamber and operating conditions to evaluate the relativeresistance of interior coatings to surface fungal growth in asevere interior environment during a 4-week period.1.2 This test method can be used to evaluate the compara-tive resistance of interior coatings to accelerated mold growth.Performance at a certain rating does not imply any specificperiod of time for a fungal free coating.However,a better ratedcoating nearly always performs better in actual end use.NOTE1This test method is intended for the accelerated evaluation ofan interior coatings resistance to fungal defacement.Use of this testmethod for evaluating exterior coatings performance has not beenvalidated,nor have the limitations for such use been determined.If thistest method is to be used for the testing of an exterior coating system,aprecautionary statement regarding interpretation of results as beingoutside of the scope of this test method must be included in the test report.Any accelerated weathering(leaching,weathering machine exposure,etc.)should be reported and should also bear reference to the fact that it isbeyond the current scope of this test method.1.3 Temperature and humidity must be effectively con-trolled within the relatively narrow limits specified in order forthe chamber to function reproducibly during the short testperiod.Severity and rate of mold growth on a film is a functionof the moisture content of both the film and the substrate.Arelative humidity of 93%at a temperature of 32.5 6 1 C(906 2 F)is necessary to initiate and maintain mold growth andfor test panels to develop rapidly and maintain an adequatemoisture level to support mold growth.1.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international 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)Committee.2.Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Significance and Use3.1 An accelerated test for determining the resistance ofinterior coatings to mold growth is useful in estimating theperformance of coatings designed for use in interior environ-ments that promote mold growth and in evaluating compoundsthat may inhibit such growth and the aggregate levels for theiruse(see also Note 1).3.2 This test method should preferably be used by personswho have had basic microbiological training.4.Apparatus4.1 Environmental Chamber,capable of maintaining a rela-tive humidity of 93%at a temperature of 32.5 6 1 C(90 62 F)while providing a continuous inoculation of the surfaceof the exposed test panels with mold spores.The chambercould be a stand-alone unit3that maintains the specifiedtemperature and humidity and can accommodate the sampleholding tank(Fig.1)or an environmental room that fits one ormultiple sample holding tanks.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.Current edition approved Nov.1,2021.Published December 2021.Originallyapproved in 1973.Last previous edition approved in 2016 as D3273 16.DOI:10.1520/D3273-21.2For 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.3An example of this equipment is Model Hastest HST-800B-LJS.Copyright ASTM International,100 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 e