BWC’sDivisionofSafety&HygieneSafetyTalkStaticelectricityhazardsUndercertainconditions,liquids,solidobjectsandpeoplecanbecomechargedwithstaticelectricity.Ifthesechargescannotmoveorflowtoground,thestaticchargescontinuetoaccumulate,andwilleventuallydevelopenoughenergytojumpasasparktoanothernearbyobject.Ifflammablegasorvaporispresentwhenthisoccurs,thissparkcanigniteafireorcauseanexplosion.Everyonehasprobablyexperiencedastaticelectricityspark(andshock)atonetimeoranother.Thisusuallyhappensinthewinterwhenthereisnotmuchmoistureintheair(humidityislow),butcanoccuranytimeofyear.Reviewthesourcesofstaticelectricitywiththegroup.Writethesetermsonawhiteboardorflip-chartforlaterreference.OTriboelectrificationoccurswhentwodifferentmaterialsmakecontactandthenseparate(walkingacrossacarpet).OLiquidshearchargingiscreatedbytheflowofliquidsthroughapipe,hoseorvessel(fillingatanktruckthroughaloadingpipe).Freefallingliquidsthroughaircanalsogeneratestaticcharge.OInductionchargingoccurswhenaneutralungroundedobjectmovesintotheelectricfieldthatsurroundsahighlychargedobject(walkingonawoodfloorandtouchingachargedobject).OCoronachargingiscausedwhenanonconductiveobjectissprayedwithastreamofmaterialthatiselectricallycharged(electrostaticpaintspraying).MethodstopreventstaticelectricitydischargeDiscusswiththegroupeachofthesesevenwaystoreduceoreliminatestaticelectricity.Askthemtoidentifylocationsinthefacilitywhereexamplesmaybefound.OBond–connecttwoormoreconductiveobjectstogetherwithaconductor(likeawire)toequalizethepotentialchargebetweenthem.OGround–connectoneormoreconductiveobjectsdirectlytotheearthwithaconductor(likeawireorsteelrod).OHumidification–moistureintheair(humidityabove60percent)canhelpdissipatestaticchargesonobjects.ByArneLarsonBeforeyoubeginSurveyyourfacilitytoidentifyactivitiesthathavepotentialtocreatestaticelectricitysparking.Reviewsafetyproceduresatyourcompanydesignedtopreventhazardscausedbystaticelectricity.Ifavailable,bringexamplesofbondingandgroundingdevicestodemonstratetheiruse.•Increaseconductivityofaliquidbyusinganti-staticadditives,ormixinginothermoreconductiveliquids(forexample,ethanol,acetone).•In-linemicrofilterscancauserapidchargingoflowconductivityliquids.•Enclosefiltersinagroundedmetalenclosure.•Plasticbagsanddrumlinerscangeneratestaticchargeswhenpulledapartoracrossothermaterials.OStatic-dissipatingsolesonshoesandtreatedorcottonclothingcanhelpreducestaticbuildup.OInspectandrepairgroundingwires,straps,connections,clamps,etc.toensureagoodpathtogroundismaintained.ArneLarsonisasafetyspecialistwiththeLubrizolCorp.’sresearchandtestingfacilityinWickliffe,Ohio.Hehas16yearsofexperienceinsafetyandindustrialhygiene.WealwaysstrivetoimprovetheSafetyLeader’sDiscussionGuide.Yourfeedbackcanhelp.Pleasesendyourcommentsviae-mailtoSafety@ohiobwc.com.ReferencesWebsitesxPublication•RecommendedPracticeonStaticElectricity,NFPA77,NationalFireProtectionAssociation.OAdditives–certainfueladditivescanincreasetheconductivityoftheliquid.OStaticcollectors–highlyconductivedevicesthatcollectstaticchargesfromnon-conductivesourcesandsafelychannelittoground.OMaterials–conductiveflooringandshoesolescanhelpdissipatestaticchargesawayfromtheperson.OMinimizesplashfillingandfree-falloflowconductivityflammableliquids.TypesofstaticdischargesAskthegrouptoidentifysituationsatyourfacilitywherestaticdischargesmayoccur.OCapacitivedischarge–sparksthatoccurbetweenconductiveobjects,suchasametaldrumandametalcontainer.OBrushdischarge–mayoccurwhenagroundedconductorcomesclosetoachargednon-conductiveobject.Forexample,removingasweaterandputtingitonametalhangerrod.ONote:thereareothertypesofdischargesassociatedwithpowdersandpowdercoatingoperations.Seereferencematerialsformoreinformation.PreventingfiresandexplosionsDiscusswiththegroupthesafetyprecautionslistedbelowforworkingwithflammableliquids,gases,vaporsandduststominimizegenerationofstaticelectricity.Askiftheycanthinkofanyotherwaystopreventstaticsparking.OBondandgroundallmetallicequipment.OBondingandgroundingarebothrequiredwhenhandlingflammableliquids.ONon-metallicpipingandcontainerscannotbebondedandgrounded.Ifpossible,thesematerialsshouldnotbeusedtohandleflammableliquids.OSpecialcareisrequiredwhendispensingflammableliquids.•Minimizesplashfillingandfreefallasmuchaspossible.•Reducetheflowrateoftheliquid.Aslowerliquidvelocityhelpsminimizeagitationandturbulence.Fromthe2006SafetyLeader’sDiscussionGuide
优质VIP
