Industrial Health and Safety Criteria for Abrasive Blast ...

1 ' ' , ,fortheDivisionofLaboratoriesandCriteria Development, , (NIOSH)75-122 Singlecopiesareavailablefrom:OfficeofTec hnicalPublicationsNationalInstituteforOc cupationalSafetyandHealthPostOfficeBuild ingCincinnati,Ohio45202-(513/ 684-2723)Pleaseincludea :BethlehemSteelCorporation,Steelton,Penn sylvaniaWestEndIronWorks,Cambridge,Massa chusettsHaarmanSteelCompany,Willimansett ,MassachusettsAbrasiveBlastingandCoating Company,Springfield,MassachusettsBrownan dSharpeManufacturingCompany,Providence,R hodeIslandSanstormCompany,aDivisionofthe BigThreeIndustries,Houston,TexasTennesse ePipelineCompany,Cleveland,TexasBaylorCo mpany,Sugarland,TexasMiddlesexWeldingand SupplyCompany,Somerville,MassachusettsUn itedStatesNavy,Boston,MassachusettsUnite dStatesCoastGuard,Boston,MassachusettsAm ericanNationalStandardsInstitute,Committ eeon:SafetyCodeforExhaustSystemsClemco-C lementina,Ltd.,SanFrancisco, ,Oakland,CaliforniaCycloneAbrasiveBlasti ngEquipmentCompany,Stockton, ,Belmont,CaliforniaPangbornDivision,TheC arborundumCompany,Hagerstown,MarylandWhe elabrator-FryeInc.

2 ,Mishawaka,IndianaBobSchmidtInc.,Houston ,TexasPauli&GriffinCompany,SanFrancisco, CaliforniaHodgeClemco,Ltd.,Sheffield,Eng landPressureBlastManufacturingCo.,Inc.,M anchester,ConnecticutAlexanderSaunders&C o.,Inc.,ColdSpring,NewYorkTritonCorporat ion,Houston, ,Sausalito,CaliforniaWewouldalsoliketoth ankthevariouslabororganizations,privatec ompanies,abrasiveblastcleaningandpersona lprotectiveequipmentmanufacturers, (CONT'D) ~. (UnderHelmet) ' -InstallationsSurveyedAppendixB -TestEquipmentandProcedureviA-IB-1viiLIS TOFFIGURESLISTOFFIGURES(CONT'D) ,Hand-HeldNozzle(InstallationP-l)A-16 BlastOperatorEnvelopedbyDustCloud5623456 78 PortableBlastCleaningUnitwithOperatorInt eriorofBlastCleaningRoomHand-OperatedCab inetTypeBlastCleaningMachineAutomaticSwi ngTableBlastCleaningMachinePortableWetBl astCleaningMachineDustEvaluationForm(Sam ple)232426282954A-2A-3A-4A-SA-6 PortableBlastCleaningUnit(InstallationP- 2)PortableBlastCleaningMachine,Hand-Held NozzleCleaningShipinDrydock(Installation P-4)PortableBlastCleaningMachine,Hand-He ldNozzle(InstallationP-5)PortableBlastCl eaningMachine,Hand-HeldNozzle(Installati onP-6)ExhaustBlowersandDuctingtoOpenYard (InstallationP-9)

3 A-20A-28A-32A-36A-4791011121314 BlastOperatorEnvelopedbyDustCloud57 NeglectedRespiratedHelmet58 UnprotectedWorkerClearingDustCollectionH opper61 ParticleSettlingTime70 OctaveBandMeasurementsatSelectedFaciliti es, (InstallationP-9)AreaSurroundingBlastCle aningApparatus(Installation~-3)GCAC orporationRespirableDustMonitorDatametri csSeries800-VTPA irflowMultimeterSoundLevelMonitoringInst rumentationA-48A-68B-2B-6B-715 Flat,C,andA-WeightingScalesareCommonlyin Use;D2isRecommended9316 Hand-OperatedPortableBlastCleaningMachin e9817 UnguardedBeltDriveforExhaustFan10118 MoundsofAbrasiveWasteMaterial10319 OpenElectricalConnectionBoxandAccumulate dWaste10720 TumbleBlastCleaningMachine10921 OpenWasteContainerandDischargeNearWorkSt ationIIIviiiB-4 MicrophonePositionRelativetoBlastOperato r'sEarforInsideHelmet ,Education,andWelfare,DivisionofLaborato riesandCriteriaDevelopment,NationalInsti tuteforOccupationalSafetyandHealth,Cinci nnati,Ohio, , Safety ,andhealthcriteriaandtosubstantia llyimprovepersonalprotectiveequipmentfor abrasiveblastcleaningoperatorsandotherwo rkerswho,duetoproductionflowrequirements ,spacerestrictions, ~Theywereunstintinginprovidingcatalogs,t echnicalinformation, ,production,andsalesengineersuntilalltea mmemberswerefullyindoctrinatedintopast,p resent, ,rules,andregulationshavebeenlackingform anyyears, ~.

4 Whichincludedbothfederalandprivateindust rialfacilities, , ,during, ~alprotectiveequipmentsuchasshortduratio nheadmasks,self-containedbreathinghelmet s(someofwhichareairconditioned),capes,le ggings,chaps,gloves,breathingairpurifier s, Downdraftandcrossdraftblastingrooms,usin gsteelshotandslagabrasives,providedgoodw orkingvisibilityinallcaseswheretheairflo wratewasatorabove18 Alargehood,withceilingexhaustedairflow, Ashipboardtank,ventilatedat57 CFM/FT2, Enclosed,ventilatedfacilitiessuchasblast ingrooms,wheningoodrepair, Enclosedfacilitiessuchasblastingrooms,in moderatedisrepairwithleakagethroughdoors eals,andthroughholesworninwalls,develope donlylocalnuisancedustconcentrations. Enclosed,ventilatedautomaticandcabinetbl astingmachines,wheningoodrepair, Non-enclosed,portable, , , , , (Hediduseearplugs,however.)Hearingdamage wassubjectivelyobservedatsomefacilities, ,mostmachinesaresoldonabasicor"stripped" , ,suchitemsasdustcollectors,negativepress ureinterlock/sensingcontrolvalves,pneuma ticremotecontrolvalves,compressedairpuri fiers,moistureseparators, ' : affecttheworkers'lifesupportsystem permittheescapeofabrasivefromblastingcha mbers createadirtyanddustyenvironmentintheimme diateandnearbyworkareas , ,suchaswithsilicasand, ,aswithnontoxicabrasivessuchassteelshot, workersshouldberequiredtouserespiratoryp rotection,suchasdustmasksand/orhoods, ,blastoperatorsmustbeprotectedwithwell-m aintained, ,hand-heldblastingnozzles, , contributetothedevelopmentofexcessivenoi selevels preventobservationoftheoperatorfromtheex teriorofacleaningbooth,room,orchamberdis tractfromtheoperatingefficiencyofdustcol lectionsystemsresultinsuddenandaccidenta labrasivehosefailurerestricttheworkers'.

5 However, ,preferably,downdraftventilationsystemss houldbedesignedtoprovideadequatedustclea ranceforvisibilitywithaminimumairflowrat eof-20 ~dpoint,certainmachinesmayhavesuperioror built-insafetyandhealthprotection;howeve r, ,counteractingthenaturaltendencyofdustto settle,providesverypoordustremovalunless unrealisticairvelocities,suchasarefoundw ithinexhaustducting, ,suchasintanksandcabinets, , , ~ ; 'slevel,althoughsomeattentionhasbeengive ntohearingconservationattheuser' , , "pots" ,SectionVIII whichdefinesdesign,materials,andc~ ~ereofcodeconstruction,anumberof"homemad e" ,ifnotallofthe40statesrequi:ethatunfired pressurevesselsbeinternallye~ , ~1ts,f~wofthevesselsviewedhadbeeninterna llyinspected~uring~heent1reper10doftheop erationlife, ;however, (masksandhoodsthatlackbreathingair,breat hing-airpurifiers,protectiveclothing,and metalair-supplyhelmets) , (alltypes)arefrequentlypositionedindense lypopulatedworkareaswherenearbyworkersar eexposedt odustan d noiselevelsthatcouldb e r evaryingdesignsof"deadman" ,tocontinuouspushbutton, , ,nonleakinghelmets, ~~~~= , otherabrasiveblastingoperationisperforme dsoastoallowgenerateddusttospreadtonearb yworkers,suitablemeasuresshouldbetakento protectthoseworkers:(1)Respiratormasksan dsafetyglassesshouldbeusedtoprotectagain stnuisance-typedusts.

6 (2)Whendustlevelsaresufficientlyheavytoc ausemarkeddiscomfort,distractionfromwork ,orahealthhazard(accordingtothebestava~l ablegUidesuchasACGIHTLV's), ~srequiringperformanceofanoperationsucha sairblowing~xcessabras~veordustfromthecl eanedobject, emandatorywhensilicasandisusedasanabrasi verega~ , ,especiallyblastingrooms,booths, , ,combinedwithvelocitiessufficienttoprovi degoodvisibilityduringblasting, (1) ,orbyothermeansof"onground"depression,cu tting,orpinchingbypedestrian, , (Figure14)fromtheFederalRegisterofDecemb er16, 'searmustbemodifiedbytheknownattenuation characteristicsofanyearprotectiondevices used.(2) , , ~ ~ ,aminimumairflowrat~?fapproximately20 ,pastexperiencehasshown80 ~ (preferablyh~gher)butn olowerthant hosefordowndraftsystemsdesignedforidenti ca (3)Onatime-usebasis,allmetalpipelines,jo ints,bends,valvesconnectorsandnozzlessho uldbesubjectedtoregularinternalinspec~io ntodete~ ~ (4)Pressure"pots"orvesselsusedinconjunct ionwitha~rasiveblastcleaningoperationssh ouldbeexaminedforinternaldeteriorat1~ ~perat10n,the"pot"orpressurevesselshould besubjectedtoahydrostat1ctestatapressure of1-1 ,asanASME/NationalBoardCommissionedInspe ctor, "pots" "pots"orvesselsshouldbeconstructedinacco rdancewithASME pressurevesselcoderequirements.

7 (5)Pop-upvalvesusedtopressurizethe"pot" ,anddefectivepartsshouldbepromptlyreplac ed.(6)Pressure"pots"orvesselsshouldbedes ignedinamannerthatwillpermitfreeandeasye ntryoft~eabrasive,reducespillin~, (7)Theinteriorfloors,ledges,andshelfsurf aces(wheneverpracticalthelattertwoitemss houldbeavoided) , (8)Blastcleaningroomsshouldbeinspectedon aregularweeklybasistodetectholes,abraded metalenclosuresurfaces, ,theinteriorofblastcleaningroomsshouldbe rubberlinedtoreduceoperatingnoiseandtopr otectthemetalsidewallsfromabrasivedeteri oration.(9)InasimilarmannertoItem8,split ordividedblastcleaningroomsthatpermitthe entryofworkonanoverheadtravelingcranesho uldhavethedivisionsealsexamined,atleastw eekly,anddefectivesealsshouldbereplacedp romptly.(10)Whenevertheblastcleaningproc essentailsthecleaningofheavyorbulkyobjec ts,anadequatemeansofhandlingsuchitemspri orto,during,andafterblastcleaningshouldb eprovided.(11)Alldoorsofablastingenclosu reshouldbekeptclosedatalltimeswhenblasti ngisbeingdoneandshouldbekeptclosedforare asonabletimeaftertheblastinghasceased.

8 (12)Allmovingmechanicaldevices,conveyorb elts, (13) (14) (15) (1)Allmotorsusedinconjunctionwithabrasiv eblastcleaningequipmentshouldbeoftotally encloseddust-proofdesign.(2)Allelectrica lcontrolsshouldbeconfinedindust-tightenc losuresmeetingthedesigncriteriaofTheNati onalElectricalManufacturersAssociation(N EMA) (3) ,state,municipal,orothersafetyinspectors .(4)Allelectricallightingwithintheconfin esofblastcleaningroomsshouldbe100percent operativeatalltimes, :(1)Anair-suppliedbreathinghelmet, (2)Theuseofhelmetsand/ormaskslackingasel f-containedsourceofbreathingairshouldbep rohibitedsincetheylackanairsealtoprevent dustentryintothehelmetormaskandarefreque ntlyusedforperiodsoftimeinexcessofthedes ignedtemporaryorshort-termuse.(3) ,thebreathingairshouldbeairconditionedan dcooledtoatemperatureintherangeof65 ' ,hishelper, (4)Self-containedbreathinghelmetsshouldb edesignedtoaccommodat~andpermittheuseofs ound-reducingearmuffseitherasb~ilt inprotect~ 'thatthe90dB(A) (5) ~eaningoperator' ~lmsovervisionglassesishighlyrecommended .

9 (6)Abrasiveblastcleaningworkersshouldbep rovidedwithandinstructedtowearsafetyboot sortoeguards.(7)Eachoperatorshouldbeprov idedwithandinstructedtowear~uitablegaunt letglovesandcoverallsthatwillpreventabra sivemater~ ~ (8)Inadditiontothestipulatedpersonalprot ectiveequipmentasuitable,cleanlockerorco ntainershouldbeprovidedforeachoperator' (9)Silicasandasanabrasivecleaningagentsh ouldbeprohibitedfromusewithallhand-helda brasiveblastcleaningmachines.(10)Noworke rthathasbeeninvolvedinextensive(over4hou rs) ~gnetospraypaintoperationswithinthesamew orkday. (1)Theexhaustfansofcabinetmachinesshould beacousticallyengineeredtotheextentthatt heresultingnoiseleveldoesnotexceedthefed erallystipulated90dB(A).(2)Allcabinetmac hines, ; (3)Theuseofopen-frontcabinetmachinesasus edinthesuedepreparationandcleaningindust ryshouldbeprohibited.(3)Al ~gn,andthecontrolboxesshouldb ekeptc losedatalltimesunlessbeingservicedbyacom petAntelectrician.

10 (4) (4). ~lyma~n~ained,andetched shadesorprotection (5)Doorsealsoncabinetunitsshouldbeinspec tedweekly,anddefectivesealsshouldbepromp tlyreplaced.(6) (7) t(1) (2)Eachmachineoperatorshouldbeprovidedwi thandinstructedtowftbearsae yootsortoeguardsduringworking'hours.(3) ;ratorwhileoperatingacabinetmachine,anwh enremovingabras~veresidueanddebrisfromth edustcollectingsystem.(8)Foot-typecontro lsusedtoactivatecabinetmachinesshouldbee quippedwithastirrup-typeguardthatwillpre ventaccidentaloperationofthemachine. (9) (1)Theinternalsurfacesofallautomaticmach inesshouldbeo~aregularweeklybasisduringw hichthefollowingitemsg1venspecialconside rationandpromptcorrectiveaction:(2)Allca binetmachinesshouldbeequippedwiththefoll owingfailsafecontrolprotection: Anegative-pressurecontrolswitchthatwillp reventoperationofthemachineunlessanegati vepressureisevidentwithinthecabinet e d wearpol"ates ,distorted,orotherwisedeterioratedfloorp latesorgratingst hatcancreateatrip,slip, ,steeltorubber, orrubbert orubber doorsealss houl dbe ,casings,orotherenclosuresthatcanresulti ntheescapeofabrasivesordustshouldberepai redorreplaced.