Designation:E1231−15StandardPracticeforCalculationofHazardPotentialFiguresofMeritforThermallyUnstableMaterials1ThisstandardisissuedunderthefixeddesignationE1231;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoversthecalculationofhazardpotentialfiguresofmeritforexothermicreactions,including:(1)Time-to-thermal-runaway,(2)Time-to-maximum-rate,(3)Criticalhalfthickness,(4)Criticaltemperature,(5)Adiabaticdecompositiontemperaturerise,(6)Explosionpotential,(7)Shocksensitivity,(8)Instantaneouspowerdensity,and(9)NFPAinstabilityrating.1.2Thekineticparametersneededinthiscalculationmaybeobtainedfromdifferentialscanningcalorimetry(DSC)curvesbymethodsdescribedinotherdocuments.1.3Thistechniqueisthebestapplicabletosimple,singlereactionswhosebehaviorcanbedescribedbytheArrheniusequationandthegeneralratelaw.Forreactionswhichdonotmeettheseconditions,thistechniquemay,withcaution,serveasanapproximation.1.4Thecalculationsandresultsofthispracticemightbeusedtoestimatetherelativedegreeofhazardforexperimentalandresearchquantitiesofthermallyunstablematerialsforwhichlittleexperienceandfewdataareavailable.Comparablecalculationsandresultsperformedwithdatadevelopedforwellcharacterizedmaterialsinidenticalequipment,environment,andgeometryarekeytotheabilitytoestimaterelativehazard.1.5Thefiguresofmeritcalculatedasdescribedinthispracticeareintendedtobeusedonlyasaguidefortheestimationoftherelativethermalhazardpotentialofasystem(materials,container,andsurroundings).Theyarenotintendedtopredictactualthermokineticperformance.Thecalculatederrorsfortheseparametersareanintimatepartofthispracticeandmustbeprovidedtostressthis.Itisstronglyrecommendedthatthoseusingthedataprovidedbythispracticeseektheconsultationofqualifiedpersonnelforproperinterpretation.1.6ThevaluesstatedinSIunitsa...
