Designation:D6954−04(Reapproved2013)StandardGuideforExposingandTestingPlasticsthatDegradeintheEnvironmentbyaCombinationofOxidationandBiodegradation1ThisstandardisissuedunderthefixeddesignationD6954;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisguideprovidesaframeworkorroadmaptocompareandrankthecontrolledlaboratoryratesofdegrada-tionanddegreeofphysicalpropertylossesofpolymersbythermalandphotooxidationprocessesaswellasthebiodegra-dationandecologicalimpactsindefinedapplicationsanddisposalenvironmentsafterdegradation.Disposalenviron-mentsrangefromexposureinsoil,landfill,andcompostinwhichthermaloxidationmayoccurandlandcoverandagriculturaluseinwhichphotooxidationmayalsooccur.1.2Inthisguide,establishedASTMInternationalstandardsareusedinthreetiersforacceleratingandmeasuringthelossinpropertiesandmolecularweightbyboththermalandphotooxidationprocessesandotherabioticprocesses(Tier1),measuringbiodegradation(Tier2),andassessingecologicalimpactoftheproductsfromtheseprocesses(Tier3).1.3TheTier1conditionsselectedforthermaloxidationandphotooxidationacceleratethedegradationlikelytooccurinachosenapplicationanddisposalenvironment.Theconditionsshouldincludearangeofhumidityorwaterconcentrationsbasedontheapplicationanddisposalenvironmentinmind.Themeasuredrateofdegradationattypicaloxidationtempera-turesisrequiredtocompareandrankthepolymersbeingevaluatedinthatchosenapplicationtoreachamolecularweightthatconstitutesademonstrablebiodegradableresidue(usingASTMInternationalbiometertestsforCO2evolutionappropriatetothechosenenvironment).Bywayofexample,acceleratedoxidationdatamustbeobtainedattemperaturesandhumidityrangestypicalinthatchosenapplicationanddisposalenvironment,forexample,insoil(20to30°C),landfill(20to35°C),andcompostingfacilities(30to65°C).Forapplicationsinsoi...
