Designation:D6691−09StandardTestMethodforDeterminingAerobicBiodegradationofPlasticMaterialsintheMarineEnvironmentbyaDefinedMicrobialConsortiumorNaturalSeaWaterInoculum1ThisstandardisissuedunderthefixeddesignationD6691;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodisusedtodeterminethedegreeandrateofaerobicbiodegradationofplasticmaterials(includingfor-mulationadditives)exposedtopre-grownpopulationofatleasttenaerobicmarinemicroorganismsofknowngeneraortheindigenouspopulationexistinginnaturalseawater.Thetestmethodisconductedundercontrolledlaboratoryconditions.1.2Thistestmethodisdesignedtoindexpolymermaterialsthatarepossiblybiodegradable,relativetoapositivereferencematerial,inanaerobicenvironment.1.3Thistestmethodisapplicabletoallpolymermaterialscontainingatleast20%carbonthatarenotinhibitorytothemicroorganismspresentinamarineenvironment.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.5ThereisnosimilarorequivalentISOstandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D618PracticeforConditioningPlasticsforTestingD883TerminologyRelatingtoPlasticsD1193SpecificationforReagentWaterD2593TestMethodforButadienePurityandHydrocarbonImpuritiesbyGasChromatographyD4129TestMethodforTotalandOrganicCarboninWaterbyHighTemperatureOxidationandbyCoulometricDetection3.Terminology3.1DefinitionsofTermsSpecifictoThisStandard—DefinitionsoftermsapplyingtothistestmethodappearinTerminologyD883.4.SummaryofTestMethod4.1Thistestmethodconsistsofthefollowing:4.1.1Selectingandcharacterizing(carboncontent,molecu-larweight)plasti...
