Designation:D6692–01StandardTestMethodforDeterminingtheBiodegradabilityofRadiolabeledPolymericPlasticMaterialsinSeawater1ThisstandardisissuedunderthefixeddesignationD6692;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestisusedtodeterminethedegreeofaerobicbiodegradationofpolymericcompoundsutilizedinplasticmaterialsbydeterminingthelevelofrespirationofsuchradiolabeledcarboncompoundstoradiolabeledcarbondiox-ide.1.2Thetestisdesignedtoutilizethenaturallyoccurringmicrobesinseawaterastheinoculumfortheenrichmentandsubsequentmineralization(biodegradation)ofthetestpolymerusingitasacarbonandenergysourceresultinginacarbondioxideasanendproduct.1.3Thetestmethodrequiresthatthepolymerstobeassayedaresynthesizedusingtheradioisotope,carbon-14,andthatthecompoundorplasticmaterialbeuniformlylabeledwithcarbon-14.1.4Ascontrols,knownbiodegradablecompounds,suchasglucoseorstarch,alsouniformlylabeledwithcarbon-14,areruninordertodeterminethebiologicalactivityofthenaturalpopulation.1.5Theconcentrationofaddedpolymersshallbekeptlowsoasnottocauselimitationbyoxygen,andtheseawaterinoculumisamendedwithnitrogenandphosphoruscom-poundstoensurethatgrowthinnotlimitedbythesenutrients.1.6Thesafetyproblemsandregulationsassociatedwithworkingwithradioactivematerialsarenotaddressedinthemethod.Itistheresponsibilityoftheindividualuserstoestablishandensureadherencethepropersafety,health,monitoringandallregulatorypracticesassociatedwiththeuseofradioactivecompounds.1.7ThereisnosimilarorequivalentISOstandard.2.ReferencedDocuments2.1ASTMStandards:D883TerminologyRelatingtoPlastics2D5296TestMethodforMolecularWeightAveragesandMolecularWeightDistributionofPolystyreneByHighPerformanceSizeExclusionChromatography3D6340DeterminingAerobicBiodegradationofRadiola-beledPlasticMaterialsinanA)AqueousorB)Compo...
