ASTM_D_3273_-_12.pdf

Designation:D327312Standard 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 a small environmental cham-ber and the conditions of operation to evaluate reproducibly ina 4-week period the relative resistance of paint films to surfacemold fungi,mildew growth in a severe interior environment.The apparatus is designed so it can be easily built or obtained2by any interested party and will duplicate results obtained in alarge tropical chamber.1.2 This test method can be used to evaluate the compara-tive resistance of interior coating to accelerated mildewgrowth.Performance at a certain rating does not imply anyspecific period of time for a fungal free coating.However,abetter rated coating nearly always performs better in actual enduse.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.Any acceleratedweathering(leaching,weathering machine exposure,etc.)should bereported and should also bear reference to the fact that it is beyond thecurrent 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 95 6 3%at a temperature of 32.5 6 1C(90 6 2F)is necessary for test panels to develop rapidly andmaintain an adequate moisture 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3E177 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 95 6 3%at a temperature of 32.5 6 1C(906 2F)while providing a continuous inoculation of the surfaceof exposed panels with mold spores.The chamber should bekept in a room controlled to no less than 21C(75F)so thatheat loss from the cabinet is insignificant and that 92 to 98%relative humidity is readily obtained at the test temperature.Alternatively the cabinet must be insulated with suitablematerials to minimize heat loss.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 Feb.1,2012.Published March 2012.Originallyapproved in 1973.Last previous edition approved in 2005 as D3273 00(2006).DOI:10.1520/D3273-12.2Additional specifications for construction of a chamber that has been foundsuitable for this method may be obtained from New Jersey Industrial Controls,P.O.Box 601,Rockaway,NJ 07866.3For 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 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.2 Cabinet,suitable to accommodate the desired number oftest panels,typically a minimum of twenty-five 75 by 100-mm(3 by 4-in.)panels under the