Designation:D6974−20StandardPracticeforEnumerationofViableBacteriaandFungiinLiquidFuels—FiltrationandCultureProcedures1ThisstandardisissuedunderthefixeddesignationD6974;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticecoversamembranefilter(MF)procedureforthedetectionandenumerationofHeterotrophicbacteria(HPC)andfungiinliquidfuelswithkinematicviscosities≤24mm2·s-1atambienttemperature.1.2ThisquantitativepracticeisdrawnlargelyfromIPMethod385andTestMethodD5259.1.3Thistestmaybeperformedeitherinthefieldorinthelaboratory.1.4Theabilityofindividualmicrobestoformcoloniesonspecificgrowthmediadependsonthetaxonomyandphysi-ologicalstateofthemicrobestobeenumerated,thechemistryofthegrowthmedium,andincubationconditions.Consequently,testresultsshouldnotbeinterpretedasabsolutevalues.Rathertheyshouldbeusedaspartofadiagnosticorconditionmonitoringeffortthatincludesothertestparameters,inaccordancewithGuideD6469.1.5Thispracticeoffersalternativeoptionsfordeliveringfuelsamplemicrobestothefiltermembrane,volumesordilutionsfiltered,growthmediausedtocultivatefuel-bornemicrobes,andincubationtemperatures.Thisflexibilityisofferedtofacilitatediagnosticefforts.Whenthispracticeisusedaspartofaconditionmonitoringprogram,asingleprocedureshouldbeusedconsistently.1.6ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.7Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.8Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelop...
