Designation:D6340−98(Reapproved2007)StandardTestMethodsforDeterminingAerobicBiodegradationofRadiolabeledPlasticMaterialsinanAqueousorCompostEnvironment1ThisstandardisissuedunderthefixeddesignationD6340;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thesetestmethodsdirectlydeterminetherateanddegreeofbiologicaloxidationofcarboninplasticmaterialswhenplacedinacompostingenvironmentcontainingsimu-latedmunicipalsolidwasteoranaqueousenvironmentunderlaboratoryconditions.1.2TestMethodAutilizesamixedculturederivedfromthetargetenvironment(wastewater,sewagesludge,composteluant,andotherenvironmentalsources).Temperature,mixing,andaerationaremonitoredandcontrolled.1.2.1Thismethodhasthesensitivitytodeterminebiodeg-radationatconcentrationscommonlyfoundintheseenviron-ments.1.3TestMethodBstartswithfreshcompostandproceedsthroughthenormalcompostingprocesstoanearlymaturestage.Temperature,aeration;andmoisturearemonitoredandcontrolled.1.3.1Thismethodcandeterminebiodegradationatlevelsoftheplasticcommonlyexpectedinmunicipalsolidwaste.1.4Thesetestmethodsrequirethatthetargetcomponentoftheplasticmaterialbesynthesizedusingtheradioactiveisotopecarbon-14.Dependingupontheobjective,eitheraportionofthecomponentsoftheplasticorallofthecarboncanbeuniformlylabeledwithcarbon-14.Thetestmethodwilldeter-minehowthatlabeledportionwillbemetabolizedandbio-logicallyoxidizedbythemicroorganismsinthesystemtested.1.5Thesetestmethodscanbeappliedtoanycarbon-14labeledcompoundaswellasforplasticmaterialsthathavebeenformulatedtobiodegradeinanaturalaerobicenviron-ment.1.6Thesynthesisandpreparationoftheradiolabledplasticisbeyondthescopeofthesemethods.Carbon-14labeledpolymersmaybepurchasedfromanumberofcommerciallabs.1.7TherearenoISOtestmethodsthatareequivalenttothetestmethodsinthisstandard.1.8Thesafetyprobl...
