Designation:D3273−21StandardTestMethodforResistancetoGrowthofMoldontheSurfaceofInteriorCoatingsinanEnvironmentalChamber1ThisstandardisissuedunderthefixeddesignationD3273;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thistestmethoddescribestheuseofanenvironmentalchamberandoperatingconditionstoevaluatetherelativeresistanceofinteriorcoatingstosurfacefungalgrowthinasevereinteriorenvironmentduringa4-weekperiod.1.2Thistestmethodcanbeusedtoevaluatethecompara-tiveresistanceofinteriorcoatingstoacceleratedmoldgrowth.Performanceatacertainratingdoesnotimplyanyspecificperiodoftimeforafungalfreecoating.However,abetterratedcoatingnearlyalwaysperformsbetterinactualenduse.NOTE1—Thistestmethodisintendedfortheacceleratedevaluationofaninteriorcoatings’resistancetofungaldefacement.Useofthistestmethodforevaluatingexteriorcoatings’performancehasnotbeenvalidated,norhavethelimitationsforsuchusebeendetermined.Ifthistestmethodistobeusedforthetestingofanexteriorcoatingsystem,aprecautionarystatementregardinginterpretationofresultsasbeingoutsideofthescopeofthistestmethodmustbeincludedinthetestreport.Anyacceleratedweathering(leaching,weatheringmachineexposure,etc.)shouldbereportedandshouldalsobearreferencetothefactthatitisbeyondthecurrentscopeofthistestmethod.1.3Temperatureandhumiditymustbeeffectivelycon-trolledwithintherelativelynarrowlimitsspecifiedinorderforthechambertofunctionreproduciblyduringtheshorttestperiod.Severityandrateofmoldgrowthonafilmisafunctionofthemoisturecontentofboththefilmandthesubstrate.Arelativehumidityof>93%atatemperatureof32.561°C(9062°F)isnecessarytoinitiateandmaintainmoldgrowthandfortestpanelstodeveloprapidlyandmaintainanadequatemoistureleveltosupportmoldgrowth.1.4Thevalues...
