ASTM_G_21_-_15.pdf

Designation:G2115Standard Practice forDetermining Resistance of Synthetic Polymeric Materials toFungi1This standard is issued under the fixed designation G21;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()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 practice covers determination of the effect of fungion the properties of synthetic polymeric materials in the formof molded and fabricated articles,tubes,rods,sheets,and filmmaterials.Changes in optical,mechanical,and electrical prop-erties may be determined by the applicable ASTM methods.1.2 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses are forinformation only.1.3 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:2D149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD150 Test Methods for AC Loss Characteristics and Permit-tivity(Dielectric Constant)of Solid Electrical InsulationD257 Test Methods for DC Resistance or Conductance ofInsulating MaterialsD495 Test Method for High-Voltage,Low-Current,Dry ArcResistance of Solid Electrical InsulationD618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD747 Test Method for Apparent Bending Modulus of Plas-tics by Means of a Cantilever BeamD785 Test Method for Rockwell Hardness of Plastics andElectrical Insulating MaterialsD882 Test Method for Tensile Properties of Thin PlasticSheetingD1003 Test Method for Haze and Luminous Transmittanceof Transparent PlasticsD1708 Test Method for Tensile Properties of Plastics by Useof Microtensile SpecimensE96/E96M Test Methods for Water Vapor Transmission ofMaterialsE308 Practice for Computing the Colors of Objects by Usingthe CIE System2.2 TAPPI Standard:Test Method T 451-CM-484 Flexural Properties of Paper32.3 Federal Standards:FED STD 191 Method 5204 Stiffness of Cloth,Directional;Self Weighted Cantilever Method4FED STD 191 Method 5206 Stiffness of Cloth Drape andFlex;Cantilever Bending Method43.Summary of Practice3.1 The procedure described in this practice consists ofselection of suitable specimens for determination of pertinentproperties,inoculation of the specimens with suitableorganisms,exposure of inoculated specimens under conditionsfavorable to growth,examination and rating for visual growth,and removal of the specimens and observations for testing,either before cleaning or after cleaning and reconditioning.NOTE1Since the procedure involves handling and working withfungi,it is recommended that personnel trained in microbiology performthe portion of the procedure involving handling of organisms andinoculated specimens.4.Significance and Use4.1 The synthetic polymer portion of these materials isusually fungus-resistant in that it does not serve as a carbon1This practice is under the jurisdiction ofASTM Committee G03 on Weatheringand Durability and is the direct responsibility of Subcommittee G03.04 onBiological Deterioration.Current edition approved June 1,2015.Published July 2015.Originally approvedin 1961.Last previous edition approved in 2013 as G21 13.DOI:10.1520/G0021-15.2For 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.3Available from Technical Association of the Pulp and Paper Industry(TAPPI),15 Technology Parkway South,Norcross,GA 30092,http:/www.tappi.org.4Available from Standardization Documents Order Desk,DODSSP,Bldg.4,SectionD,700RobbinsAve.,Philadelphia,PA19111-5098,http:/dodssp.daps.dla.mil.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 source for the growth of fungi.It is generally the othercomponents,such as plasticizers,cellulosics,lubricants,stabilizers,and colorants,that are responsible for fungus attackon plastic materials.To assess materials other than plastics,useof this test method should be agreed upon by all partiesinvolved.It is important to establish the resistance to microbialattack under conditions favorable for such attack,namely,atemperature of 2 to 38C(35 to 100F)and a relative humidityof 60 to 100%.4.2 The effects to be expected are as follows:4.2.1 Surface attack,discoloration,loss of transmission(optical),and4.2.2 Removal of susceptible plastici