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Health and Safety

Executive

Clearing the air Asimpleguidetobuyingandusinglocalexhaustventilation(LEV)

Executive

i l i i i l l il i ( )

Health and Safety

Clearing the air A smpe gude to buyngand usng oca exhaustvent aton LEV

Every year, thousands of people in Great Britain die of lung disease or get asthma

because of airborne contaminants they have breathed in at work. If your work

produces dust (eg flour dust in bakeries), mist (eg paint mist from spraying), fume

(eg from welding), gas (eg carbon monoxide from furnaces) or vapour (eg solvents

from painting), there may be a risk to the health of your employees.

Many employers buy local exhaust ventilation (LEV) to protect workers’ health but it

doesn’t work. This may be because it’s the wrong type or because it’s not properly

installed, used or maintained. This leaflet gives you tips on buying the right LEV and

using and maintaining it properly. This should save you money as well as protecting

your employees.

This is a web-friendly version What is LEV?of leaflet INDG408

LEV is a ventilation system that takes dusts, mists, gases, vapour or fumes out of

the air so that they can’t be breathed in. Properly designed LEV will:

■ collect the air that contains the contaminants;

■ make sure they are contained and taken away from people;

■ clean the air (if necessary) and get rid of the contaminants safely.

Why should I bother with LEV?

The law says you must control the risks from these substances (the Control of

Substances Hazardous to Health (COSHH) Regulations). Installing LEV may help

you to do this. However, this may not be what you need to solve your particular

problem and you should consider other options first, such as:

■ eliminate the source;■ substitute the material being used by something safer;

■ reduce the size of the source;

■ modify the process to reduce the duration or frequency of emission;

■ reduce the number of employees involved with a process;

■ apply simple controls, eg fitting lids to equipment.

For more information about other ways of eliminating or reducing airborne

contamination at work look at HSE’s COSHH website, www.hse.gov.uk/coshh.

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Health and Safety

Executive

What makes up an LEV system?

Hood

Inlet

Ducting

Air mover

Discharge

Air cleaner

system

Figure 1 CommonelementsofasimpleLEV

AtypicalLEVsystemwillhave:

Hood(s) tocollectairbornecontaminantsat,ornear,wheretheyarecreated

(thesource).

Ducts tocarrytheairbornecontaminantsawayfromtheprocess. Air cleaner tofilterandcleantheextractedair.

Fan mustbetherightsizeandtypetodeliversufficient‘suck’tothehood.

Discharge thesafereleaseofcleaned,extractedairintotheatmosphere.

An LEV hood may be tiny and built into a hand-held tool or it may be large

enough to walk into. Here are some examples.

Figure 2 On-toolextraction– Figure 3 On-toolextraction– Figure 4 Fixedcapturing

solderingiron handsander hood

Figure 5 Moveablecapturing Figure 6 Smallbooth Figure 7 Walk-inbooth

hood

How do I make sure I get the right type of LEV?

WhenLEVdoesn’tworkaswellasitshould,acommonreasonisthatthehood

doesn’tcatchorcontainthecontaminantseffectively.Itisimportanttomatchthe

hoodtothesourcethatyouwanttocontrol.

Theremaybeastandard,‘off-the-shelf’systemthatwouldbesuitableforyou.However,itneedstobefitforpurposeandcapableofadequatelycontrollingexposure.

Askyourtradeassociationorcheckindustryguides.HSEhasdevelopedafreeinternet

toolforidentifyinggoodcontrolpractice,includingLEV:www.coshh-essentials.org.uk.

Clearingtheair:Asimpleguidetobuyingandusinglocalexhaustventilation(LEV) 2of9pages

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Executive

Ifyouhavetomakeanychangestoastandardsystem,orifthereisnostandard

systemforyourindustry,gethelptowriteaspecificationofwhatyouwillneed(see

‘Usefullinks’).TakethistoyourLEVsupplierortoaventilationengineertodesigna

systemthatwillworkforyou.

Aclearspecificationwillhelpyougetwhatyouneed,andavoidany

misunderstandingswiththeLEVsupplier.Thespecificationshould:

■ describetheprocess,thecontaminant,itshazardsandthesourcestobe

controlled,andhowstringentthecontrolneedstobe.Theimportantchemical

andflammablepropertiesofsubstancesandproductsappearintheSafetyData

Sheet;

■ requireindicatorstobefittedtoshowthatthesystemisworkingproperly;

■ requiretheLEVtobeeasytouse,check,maintainandclean,takingaccount

ofotherrisks,egaccessibility,skincontamination,andwasteremovalandfilter

changingwithoutspreadingcontamination;

■ specifythatthesupplierprovidestraininginhowtouse,checkandmaintaintheLEVsystem;

■ requirethesuppliertoprovideausermanualthatdescribesandexplainsthe

LEVsystem,howtouse,check,maintainandtestit,alongwithperformance

benchmarksandschedulesforreplacingparts;

■ requirethesuppliertoprovidealogbookforthesystemtorecordtheresultsof

checksandmaintenance.

Remembertoinvolveemployeesandworkers’representativesintheselectionand

designofLEVtomakesureitiseffectiveandpractical.

■ LEVisrarelystraightforward

■ Mistakescanbecostly

■ Useaprofessionalunlessitisobviouswhattodo

How do I select an LEV supplier?

Youareresponsibleformakingsurethatyoursupplieriscompetenttodothejob,

andsoselectingtherightcontractoriscrucial.Followthesesteps:

■ Invitetenders,ideallyfromthreecontractors.

■ Provideadrawingoftheareaandtheprocessestobecontrolled.

■ Provideyourspecificationfortheworktobedone.

■ Tellpotentialcontractorsaboutanyenvironmentalorfireandexplosion

requirements.■ Askpotentialcontractorstovisitthesitetoseetheprocesses.

Onceyouhavethetenders,comparetheplansandquotationswithyour

specification.

Askpotentialsuppliers:

■ WhatexperiencedoyouhaveindesigningandprovidingLEVsystems?

■ Whatareyourprofessionalqualifications,experienceandmemberships?

■ TowhatindustrieshaveyousuppliedLEV?

■ HaveyousuccessfullyappliedLEVtosimilarprocessesoractivitiesinmy

industry?■ Canyouprovidereferences,testimonialsorexamplesshowingsuccessful

installationofLEVsystems?Contactor,preferably,visitpastcustomerstocheck

references.


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■ AreyoutiedtoaparticularrangeofLEVproducts?

■ HowwillyoushowthattheLEVprovidesadequatecontrol?

■ Whattrainingdoyouincludeforusing,checkingandmaintainingtheLEV

system?

■ OnlybuyLEVthatwilladequatelycontrolexposure–askthesupplierhowthey

willprovethis

How do I know the LEV works?

Thesupplier’squotationshouldcoveralltherequirementslaidout inyour

specification.Oninstallation,thesuppliershouldtesttheLEVtoensureitis

workingaccordingtothespecification.Thisiscalled‘commissioning’andshows

thatithasbeeninstalledproperlyandthatitcontrolsexposure.Thiswillneedyour

co-operationbecauseitshouldbedonewhennormalworkingistakingplace.

YouandyouremployeeswillneedtrainingbythesupplierinhowtheLEVworks

andhowtocheckandmaintainit.

What three documents should the supplier give me?

1 A user manual with a general specification of what the LEV system is designed to

control and how it achieves control. It should include:

■ adescriptionofthesystemwithdiagrams;

■ performanceinformationfromcommissioning;

■ adescriptionofchecksandmaintenanceandreplacementschedules,including

frequency;

■ alistingofreplaceableparts(andpartnumbers);

■ adetaileddescriptionofthespecificstatutory‘thoroughexaminationandtest’

requirementsandexposuretargets;

■ signsofwearandcontrolfailure;

■ adescriptionofhowoperatorsshouldusethesystemsoitworkseffectively.

2 A logbook that includes:

■ schedulesforregularchecksandmaintenance;

■ recordsofregularchecks,maintenance,replacementsandrepairs;

■ checksofcompliancewiththecorrectwayofworkingwiththeLEVsystem;

■ thenameofthepersonwhomadethesechecks.

3 A commissioning report that includes:

■ diagramsandadescriptionoftheLEV,includingtestpoints;

■ detailsoftheLEVperformancespecification;

■ results,suchaspressuresandvelocitiesatstatedpoints;

■ calculations;

■ writtendescriptionsofthecommissioning,thetestsundertaken,andthe

outcome.Wherenecessary,thisshouldincludeairsamplingresults;

■ adescriptionofhowoperatorsshouldusethesystemsoitworkseffectively.

■ To keep control you need a user manual, a logbook, a commissioning report and

training


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What do I need to do once the LEV is installed?

Thelawsaysthatyouneedtomakesureitcarriesonworkingproperly.Youwill

needtoregularlycheckandmaintaintheLEVovertheyearandhaveit‘thoroughly

examinedandtested’.Todothisyouwillneedtheusermanual,logbookand

training.Ifyoudon’thaveanyofthese,askyourLEVsupplierforthemorget

professionaladvice.Theworkneedstobedonebycompetentpeople(see

‘Competence’).

IfyouhaveanLEVsystemthathasn’tbeencommissioned,youwillneedtohave

itsperformancetestedtoensurethatitisadequatelycontrollingexposure.Askthe

LEVexaminertoprovideausermanualandlogbook.

Checking and maintenance

HowoftenyoucheckyourLEVandhowyoudoitwilldependonhowcomplicated

thesystemis,howlikelyitistofail,andtheconsequencesifitdoes.ComplicatedLEVthatwillhaveseriousconsequencesifitgoeswrongneedsmorefrequent

checksandmaintenance.

AsyougainmoreexperienceinrunningtheLEVsystem,youmayneedtochange

thefrequencyofyourchecksintheusermanual.

Checksandmaintenancetendtocoverfourtypesofparts:

■ movingpartsthatmaywear,suchasfanbearingsorfiltershakers;

■ non-movingparts,suchashoods,ductworkandseals(whichcansufferphysical

orchemicaldamageandwear);

■ partsthatdeterioratewithuse,suchasfiltersorflexibleducting;

■ itemsthatneedregularattention,suchasfiltersthatneedreplacing,orremoving

sludgefromawetscrubber.

IftheLEVcanbecomecontaminatedwithtoxicsubstances,youmayneedtouse

‘permitstowork’andformalmethodstatementswhenpeopleworkonthesystem.

Givepeopleresponsibilitiesforchecksandmaintenance.Thesemayoverlap,for

example:

Operator Makedailychecks,reportfaults

Safety/workers’

representativeMakeweekly,monthlychecks

Supervisor

Makeweeklychecks,arrangerepairs,correct

deviationsfromthecorrectwayofworking,record

findingsandactions

Section Identifyproblems,receiveregularreportsfromthe

manager supervisor,beresponsibleformaintenanceandtesting

WorksengineerRepairfaults,carryoutmaintenance,arrangethorough

examination


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IfthereisanyobviousdamagetotheLEVoritclearlyisn’tworkingproperly,

employeesshouldreportthisandyoushouldhaveitrepairedstraightaway.

AlsoaskemployeesusingLEV,andanyworkers’representatives,for feedbackand

suggestionsonhowtheLEVandworkingpracticescanbeimproved.

What records do I need to keep?

Inyourlogbook,keeparecordofallLEVchecksandmaintenancetoshowthat

ithasbeendoneandthattheLEVisworkingaswellasitshouldbe.Thiswill

alsohelpyoukeeptrackofrepairsandsortproblemsoutbeforetheygetmore

serious.Keepthelogbookforatleastfiveyears.Youalsoneedtokeepthorough

examinationandtestreportsforatleastfiveyears.

What is the thorough examination and test?

MostLEVsystemsneedathoroughexaminationandtestonceeachyear(legally,

youareallowed14monthsbetweentests)tomakesureitworkswelland

continuestoprotectyouremployees.SomeLEVsystems(suchasthosecontrolling

morecriticalorhigh-hazardprocesses)needmorefrequentthoroughexamination

andtesting.TheCOSHHRegulationsrequiremorefrequenttestingforsome

processes.

ThethoroughexaminationteststheLEVagainsttheperformancerecordedin

thecommissioningreport.Itshouldincludeairflowandpressuremeasurements,

checksoncontroleffectivenessand,possibly,exposuremeasurement.Ifyou

don’thavethedesignperformancedata,youwillnotknowwhetheryoursystem

isworkingcorrectly,soyoumayneedtohaveyoursystemcommissioned.Ifyoursystemhasalreadybeencommissioned,butyouhavechangedtheprocessor

layoutsincethen,youneedtore-commissionit.Aprofessionaladvisorcanhelp

youworkoutwhatyouneedtodo.

Theexaminationandtestneedstobedonebya‘competentperson’.It isn’t

normallysomethingyoucandoyourself.Youandyouremployeeswillneedto

co-operatewiththeexaminer.Givethemthe:

■ LEVcommissioningreport;

■ LEVusermanual;

■ logbookwithdetailsofchecksandmaintenanceactivities.

Theexaminerwillattacha‘tested’labeltoallhoods.Thiswill includethenameoftheexaminerandthedateofthenexttest.Ifahoodhasclearlyfailed,thena

red‘fail’labelwillbeattachedinstead,andurgentactionwillbenecessary.The

examinerwillgiveyouareportoftheexaminationandtest,whichshouldincludea

prioritisedactionplanlistinganythingthatyouneedtodo.

IftheexaminationandtestshowthattheLEVisn’tadequatelycontrollingpeople’s

exposuretoairbornecontaminants,stoptheworkandrepairtheLEV.Ifyouwant

worktocontinuewhileyouarrangerepair,employeeswillneedfurtherprotection,

suchassuitablepersonalprotectiveequipmentandrespiratoryprotection.The

systemshouldcarrythered‘fail’labeluntilithasbeenrepaired.

Ifthethoroughexaminationandtestreportactionplancontainslonglistsofrepairsandpoorperformance,thistellsyouthatyourcheckingandmaintenance

isnotgoodenough.Usethetestreportasanauditofyourproceduresandan

opportunitytoreviewallyourexposurecontrolmeasures.Improvethemifyoucan.


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■ Itisyourresponsibilitytoarrangechecks,maintenanceandthorough

examinationandtest–makesureyouusecompetentpeople

■ ThoroughlyexamineandtesttheLEVagainsttheoriginalcommissioningreport

Competence

Youmustmakesurethatanyonewhodesigns,selects,checksandmaintains

theLEVsystemanddoesthethoroughexaminationandtestiscompetent.They

shouldhavetheknowledge,skillsandexperiencetodothejobproperly.Thereare

relevantcoursesavailable(forexample,seeBOHSandCIBSEin‘Usefullinks’).

What training for operators/supervisors/managers should I provide?

Trainingshouldcoverthebasicsof:

■ theharmfulnatureofthesubstancesyouuse;■ howexposuremayoccur;

■ howtheLEVsystemworks;

■ methodsofworkingthatgetthebestoutoftheLEV;

■ howtochecktheLEVisworking;

■ theconsequencesoftheLEVfailing;and

■ whattodoifsomethinggoeswrong.

Keeptrainingrecordsforeveryone.Thisincludesrefreshertraining.Changesto

theworkprocessmeanthatLEVmayalsoneedtochange,andstaffmayneed

re-training.

LEV checklist for employers

Issue Possiblesolution

Whichsourcesare

causingexposure?

Takeadvicefromsuppliers,tradeassociations,

professionaladvisors,theHSEwebsiteandother

reliablesources.

WhattypeofLEV

systemdoIneed?

Writeaspecification.Ifnecessary,getprofessional

advice.BeveryclearaboutthetypeofLEVhood

needed.Makesurethatyouradvisorhasthe

competenceandexperienceyouneed.

HasmyLEVsystem

beeninstalledandcommissioned

properly?

MakesureyourLEVsystemisinstalledand

commissionedbyacompetentperson.Getafullcommissioningreportandusermanual.Ensuresimple

instrumentationisinstalledtocheckperformance(ega

hoodmanometer).

HaveI,andmystaff,

beenproperlytrained?

IncludetraininginyourLEVspecificationdocument.

Makesureemployeesandthepersonresponsiblefor

checkingandmaintainingthesystemaretrained.Keep

trainingrecords.

HowdoIcheckand

maintainmyLEV

system?

Lookattheusermanualwhichwilllistthechecksand

theirfrequency.Ifyoudon’thaveone,getonewritten.

Appointpeopletodothechecks,maintenanceand

repairs.Recordanycheckingandmaintenancedetailsinthelogbook.


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Issue Possiblesolution

Haveyouchangedthe

wayyouworkorthe

productionprocessbut

nottheLEV?

TreatandplanchangestotheLEVaspartofany

changetotheproductionprocess.Don’tassumeitwill

cope.GettheLEVsystemre-commissioned.

HowdoIarrangea

thoroughexamination

andtestoftheLEV?

Includethoroughexaminationandtestintheyearly

managementcycle.Makesurethatyourexaminerhas

thecompetenceandexperienceyouneed.

WhatdoIdowiththe

report?

Followtherecommendationsinthetestreportand

carryoutnecessaryrepairworkpromptly.

Theexaminerhasput

ared‘fail’labelonan

LEVhood.

Checkthetestreportforactionsneededandarrange

forrepair.Ifnecessary,providefurtherprotectionfor

youremployeesinthemeantime,includingpersonal

protectiveequipmentandrespiratoryprotection.

WhenshouldIreview

exposurecontrol

measures?

TreattheLEVexaminationandtestreportasan

auditonexposurecontrols.Thinkaboutwhatmore

youcandotostopemployeesbreathinginairborne

contaminants.

Find out more

COSHH a brief guide to the Regulations: What you need to know about the

Control of Substances Hazardous to Health Regulations 2002 (COSHH) Leaflet

INDG136(rev3)HSEBooks2005www.hse.gov.uk/pubns/indg136.pdf

(ArevisedCOSHHleafletwillreplacethisversionin2008)

Controlling airborne contaminants at work: A guide to local exhaust ventilation (LEV)

HSG258HSEBooks2008ISBN9780717662982

Time to clear the air! A workers’ pocket guide to local exhaust ventilation (LEV)

PocketcardINDG409HSEBooks2008(Singlecopyfreeorpricedpacksof25

ISBN9780717663002)

Control of substances hazardous to health (Fifth edition). The Control of

Substances Hazardous to Health Regulations 2002 (as amended). Approved Code

of Practice and guidance L5(Fifthedition)HSEBooks2005ISBN9780717629817

SeealsoHSE’sCOSHH essentials atwww.coshh-essentials.org.uk


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Useful links

Chartered Institution of Building Services Engineers (CIBSE) www.cibse.org.

Mainprofessionalengineeringbodyofferingqualificationsandmembershipto

ventilationengineers.

Heating and Ventilating Contractors’ Association (HVCA) www.hvca.org.uk.

Mainrepresentativeorganisationforcompaniesinstallingventilationsystems

includingLEV.

British Occupational Hygiene Society (BOHS) www.bohs.org.Forhelpwith

processandsourceassessmentandLEVdesignandspecification,aswellas

qualificationsindesigningandtestingLEV.

Institution of Occupational Safety and Health (IOSH) www.iosh.co.uk.

ForgeneraladviceonchoosingLEVsystems.

Safety Assessment Federation (SAFED) www.safed.co.uk.

Representsmanyinsurancecompaniesdoingindependentengineeringinspectionand

certificationofmachineryandequipmentincludingLEVsystems.

Independent National Inspection and Testing Association (INITA) www.inita.org.uk.

Representscompaniesdoingindependentengineeringinspectionandcertification

ofmachineryandequipmentincludingLEVsystems.

Solids Handling and Processing Association (SHAPA) www.shapa.co.uk.

RepresentsthemajoremployersinLEVmanufacturing.

Further information

HSEpricedandfreepublicationsareavailablebymailorderfromHSEBooks,POBox

1999,Sudbury,SuffolkCO102WA Tel:01787881165 Fax:01787313995Website:

www.hsebooks.co.uk(HSEpricedpublicationsarealsoavailablefrombookshopsand

freeleafletscanbedownloadedfromHSE’swebsite:www.hse.gov.uk.)

ForinformationabouthealthandsafetyringHSE’sInfolineTel:08453450055

Fax:08454089566Textphone:08454089577 e-mail:[email protected]

writetoHSEInformationServices,CaerphillyBusinessPark,CaerphillyCF833GG.

This leaflet contains notes on good practice which are not compulsory but which you

may find helpful in considering what you need to do.

Thisleafletisavailableinpricedpacksof15fromHSEBooks,ISBN9780717663019.

SinglefreecopiesarealsoavailablefromHSEBooks.

©Crown copyright Thispublicationmaybefreelyreproduced,exceptfor

advertising,endorsementorcommercialpurposes.Firstpublished05/08.

PleaseacknowledgethesourceasHSE.


PublishedbytheHealthandSafetyExecutive INDG408 05/08

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