Designation:E2625−09(Reapproved2017)StandardPracticeforControllingOccupationalExposuretoRespirableCrystallineSilicaforConstructionandDemolitionActivities1ThisstandardisissuedunderthefixeddesignationE2625;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONSilicondioxide(silica,SiO2)isencounteredinnatureandindustryinawidevarietyofforms.Theserangefromessentiallyanhydroustypeswithorwithoutaveryhighdegreeofcrystallinity,tohighlyhydroxylatedorhydratedtypeswhichareamorphousbyX-raydiffractionexamination.Crystallinesilica2existsinanumberofformsorpolymorphs.Thethreemajorforms,quartz,cristobalite,andtridymite,pertaintothispractice.Quartz(oralphaquartz)isthemorecommonformencounteredasairborneparticulates.Twoofthepolymorphs,cristobaliteandtridymite,areformedatelevatedtemperaturesandaremuchlesscommoninnature,butmightbeencounteredinseveraloccupationswheresilicasarefired(calcined)athightemperatures.3Thesesilicamaterialshaveabroadrangeofphysicalandchemicalproperties.1.Scope1.1Thispracticedescribesseveralactionstoreducetheriskofharmfuloccupationalexposuresinenvironmentscontainingrespirablecrystallinesilica.Thispracticeisintendedfortheuniqueconditionsduringconstructionanddemolitionactivi-ties.1.2HealthrequirementsrelatingtooccupationalexposuretorespirablecrystallinesilicanotcoveredinthispracticefallunderthejurisdictionofPracticeE1132.1.3Nothinginthispracticeshallbeinterpretedasrequiringanyactionthatviolatesanystatuteorrequirementofanyfederal,state,orotherregulatoryagency.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.5Thisinternationalstandardwasdevelopedinac...
