OHSCO Heat Stress Awareness Guide

HEAT STRESS AWARENESS GUIDE

Included in this guide:

HEAT STRESS AWARENESS TOOL & POSTER

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Heat stress can harm or even kill people working under very hot conditions.

To help employers and workers learn how to prevent heat stress, this guide

summarizesthecauses,symptoms,andtreatmentofheat-relatedillness

presentsafive-stepapproachforusingtheHumidextoassessheatstresshazards

outlinesspecificactionsformanagingandcontrollingheatstress

KeyinformationpresentedinthisguideissummarizedintheHeat Stress Awareness Tool(seepage7).


EXCERPT FROM CORONER’S REPORT –

…when the college student started his summer job

as a garbage collector. His second day on the job,

he was overcome by heat stress symptoms. He wasn’t

trained to recognize the warning signs. As a

result, he kept working until he collapsed and fell

into a coma. He died 17 days later. This Inquest

concludes that death could have been prevented

if the employer had a heat stress program that

included training to recognize the symptoms…

The appendices include:

aself-auditchecklist

anexampleofaheatstresspolicy

anoutlineoftheessentialelementsofaheatstressprogram

someusefulcontactinformation

YourHealth and Safety Association,theWorkers Health and Safety Centre,andtheOccupational Health Clinics for Ontario Workerscanprovideyouwith:

technicalsupport

workplace-specificinformation

trainingoninjuryandillnessprevention

consultingservices


Table of contents

Isheatstressaconcerninyourworkplace?. . . . . . 3

Thelaw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Factorsinfluencingheatstress. . . . . . . . . . . . . . . . 4

Canyougetusedtoheat?. . . . . . . . . . . . . . . . . . . 4

Causes,symptoms,andtreatment. . . . . . . . . . . . . 5

Howisheatstressmeasured?. . . . . . . . . . . . . . . . . 6

Fivestepstoreduceheatstress. . . . . . . . . . . . . . . 6

Instructionsforuseoftheawarenesstool. . . . . . . 7

Heatstressacclimatization. . . . . . . . . . . . . . . . . . . 8

Managingheatstress. . . . . . . . . . . . . . . . . . . . . . . 8

Controlmeasures: General,job-specific,andpersonal. . . . . . . . . . 9

Appendices

A Sampleheatstresspolicy. . . . . . . . . . . . . . . . 11

B Heatstressreferencechart . . . . . . . . . . . . . . 12 TwoHumidexguidelines. . . . . . . . . . . . . . . . . 13

C Self-auditchecklist . . . . . . . . . . . . . . . . . . . . . 14

D Essentialsforasuccessful heatstressprogram . . . . . . . . . . . . . . . . . . . . 16

E Researchandsupport (includingwebsitecontacts). . . . . . . . . . . . . . 18

F EnvironmentCanadacontacts. . . . . . . . . . . . 19

Disclaimer

Thematerialcontainedinthismanualisforinformationandreferencepurposesonlyandnotintendedaslegalorprofessionaladvice.Theadoptionofthepracticesdescribedinthismanualmaynotmeettheneeds,requirements,orobligationsofindividualworkplaces.

Use,reproduction,andduplicationofthismanualisrecommendedandencouraged.

OccupationalHealthandSafetyCouncilofOntario(OHSCO)

XX%

5252A CSAO (04/07) © 2007, WSIB Ontario. Printed in Canada

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About this guide

TheHeat Stress Awareness GuidewasdevelopedbythemembersoftheOccupationalHealthandSafetyCouncilofOntario(OHSCO)*toprovideinformationandadviceonmanagingandcontrollingheatstressintheworkplace.

TheaudienceforthisGuideincludesemployers,managers,supervisors,workers,jointhealthandsafetycommittee(JHSC)members,healthandsafetyrepresentatives,andworkplaceunionrepresentatives.Unions,employerassociations,andhealthandsafetyprofessionalsmayalsofindtheinformationinthisGuideuseful.

*ForalistofOHSCOmembersseeAppendixE.

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Is heat stress a concern in your workplace? Hasanyonebeenaffectedbyheatinyourworkplace?

Arefansneededtokeepworkerscool?

Isworkdoneindirectsunlight?

Arethereheat-producingprocessesorequipmentintheworkplace?

Doworkerswearextraclothing/protectiveequipmentthatcanmakethemhot(e.g.,overalls,respirators,hardhats,etc.)?

Haveworkerseverexpressedconcernaboutheatintheworkplace?

Chancesarethatyouanswered“yes”toatleastoneofthesequestions.Actually,heatstressissomethingmostworkplacesmustdealwith—notjustthosewithworkersworkinginthehotsunorbesidehotfurnacesormachinery.

Thepurposeofthisheatstresstoolkitistoprovideworkplacepartieswithstrategiesfor:

recognizingthesymptoms

assessingtherisk

puttingtogetheraneffectivecontrolprogram

The law

EmployershaveadutyunderSection25(2)(h)oftheOccupational Health and Safety Acttotakeeveryprecautionreasonableinthecircumstancesfortheprotectionofaworker.Thisincludesdevelopingpoliciesandprocedurestoprotectworkersinhotenvironmentsduetohotprocessesorhotweather.Forcompliancepurposes,theMinistryofLabourrecommendsthecurrentthresholdlimitvalue(TLV)forheatstressandheatstrain,publishedbytheAmericanConferenceofGovernmentalIndustrialHygienists(ACGIH).Thesevaluesarebasedonpreventingunacclimatizedworkers’coretemperaturesfromrisingabove38°C.SeeMinistryofLabourwebdocument“Heatstresshealthandsafetyguideline”fordetails.

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HEAT RASH

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pluggedsweatglands

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severeitching

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SUNBURN

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Toomuchexposuretothesun

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andpeelingskin

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Iftheskinblisters,seekmedicalaid,useskinlotions(avoidtopicalanaesthetics)andworkintheshade

HEAT CRAmpSC

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Heavysweatingdrainsaperson’sbodyofsalt,whichcannotbereplacedjustbydrinkingwater

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Painfulcrampsinarms,legs,orstomachthatoccursuddenlyatworkorlaterathome

Heatcrampsareseriousbecausetheycanbeawarningofothermoredangerousheat-inducedillnesses

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Movetoacoolarea;loosenclothinganddrinkanelectrolyte-replacementbeverage,ifthecrampsaresevereordon’tgoaway,seekmedicalaid

Can you get used to heat?

Yes.Thebodywillgetusedtoworkinginahotenvironmentgraduallyovertime.Thisprocessofthebodybecomingmoreefficientatcoolingitselfdownisknownas“acclimatization”:

Thebodyredirectsbloodtotheskin’ssurface

Theheartbecomesmoreefficient

Sweatingstartssooner,andthereismoreofit

Sweatcontainslesssalt

Duringthisadjustmentperiod,symptomsoffatigue,dizziness,heatrash,andstomachdiscomfortarecommon.Acclimatizationtakestime—aruleofthumbforassumingyouhaveacclimatizediswhenthelastfiveofsevendayshaveworkplacetemperaturesintheheatstressrange.Itshouldbenoted,however,thatdehydrationcancancelthebenefitsofacclimatization.Acclimatizedworkerswillgenerallybeabletoworklongerinahotenvironmentthanunacclimatizedworkers.

Factors influencing heat stress

Theheatingandcoolingbalanceinthebodydependsonthefollowingfactors:

airtemperature

humidity(moistureintheair)

radiantheatload(sun,furnaces,moltenmaterial,steam,etc.)

physicalactivity(howhardyou’reworking)

cooling(bytheevaporationofsweat)

bodyadjustments(acclimatization)

Therearetwosourcesofheatexposure,theoutsideenvironmentandinternalmuscleactivity.(80%ofmuscleenergyisturnedintobodyheat.)Hightemperaturesandhighlevelsofphysicalworkcreateheatstress.Thebodycoolsitselfbyevaporatingsweat.Highhumidityhinderssweatfromevaporating.

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FAINTING

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Suddenfaintingafteratleasttwohoursofwork;coolmoistskin;weakpulse

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GET mEDICAL ATTENTIONAssessneedforCPR;movetoacoolarea;loosenclothing;makepersonliedown;andwhen the person is conscious,offersipsofcoolwater.

Faintingmayalsobeduetootherillnesses.

HEAT ExHAUSTION

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Fluidlossandinadequatesaltandwaterintakecausesthebody’scoolingsystemtostarttobreakdown

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Heavysweating;cool,moistskin;bodytemperatureabove38°C;weakpulse;normalorlowbloodpressure;tiredandweak,nauseaandvomiting;verythirsty;pantingorbreathingrapidly;blurredvision

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GET mEDICAL AID Thisconditioncanleadtoheatstroke,whichcankill;movethepersontoacoolshadedarea;loosenorremoveexcessclothing;providecoolwatertodrink;fanandspraywithcoolwater

Causes, symptoms, and treatment

Heatstresssymptomsareasetofnaturalsignalstellingyouthatsomethingneedstobedonetobalanceyourbody’sheatingandcooling.Asyourbodyheatsup,ittriestoriditselfofexcessheatthroughtheevaporationofsweat.Ifitisunabletocoolitselfthisway,yourbodytemperaturewillincrease.Whenbodytemperaturegetsabove38-39°C,thebrainstartstooverheat,leadingtoashutdownofyourbody’scoolingsystem(sweatingstops).Yourtemperaturenowrisesevenfaster,leadingtoheatstrokeandpossiblydeath.Thecauses,symptoms,andtreatmentofvariousheat-relatedillnessesarelistedbelow.

HEAT STROkE

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Ifaperson’sbodyhasusedupallitswaterandsaltreserves,itwillstopsweating,whichcancausebodytemperaturetorise;heatstrokemaydevelopsuddenlyormayfollowfromheatexhaustion

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Highbodytemperature(above41°C)andanyofthefollowing:thepersonisweak,confused,upset,oractingstrangely;hashot,dry,redskin;afastpulse;headacheordizziness;inlaterstages,apersonmaypassoutandhaveconvulsions

THIS IS AN ImmEDIATE mEDICAL EmERGENCY. pROmpT ACTION mAY SAVE THE pERSON’S LIFE

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CALL AN AmBULANCEThisconditioncankillapersonquickly;removeexcessclothing;fanandspraythepersonwithcoolwater;offersipsofcoolwater,if the person is conscious

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� Steps toStep 1 Training Measurementsbythemselvescannotguaranteeworkerprotectionfromheatstress.Itisessentialthatworkerslearntorecognizetheearlysignsandsymptomsofheatstressandknowhowtopreventthem!(SeeAppendixEonpage18fortrainingresources.)

Ifit’spossible,workersneedtobeabletoaltertheirpaceofwork,takerestbreaks,anddrinkinresponsetoearlysymptoms(acupofwaterevery20minutes).Theidealheatstressresponseplanwouldletworkersregulatetheirownpaceby“listening”totheirbodies.

Step � Clothing TheHeatstressactionchartontheawarenesstool(page7)assumesworkersarewearingregularsummerclothes(lightshirtandpants,underwear,and,socksandshoes).

Ifworkerswearadoublelayerofwovenclothing(e.g.,cottonoverallsontopofsummerclothes),add5ºofHumidextotheworkplacemeasurement(usingtheHeatstressreferencechartinAppendixB,onpage12).

Estimatethecorrectionfactorforotherkindsofclothing/protectiveequipmentbycomparingthemwithcottonoveralls(e.g.,gloves,hardhat,apron,andprotectivesleevesmightbeequivalenttoalittlelessthanhalftheevaporationresistanceofoveralls,soadd1ºor2ºofHumidex).

Ifcompletelyencapsulatingsuitsareworn,heatstressshouldbemanagedbymonitoringvitalsigns,asrecommendedbytheACGIHTLV.

Step � Select a measurement location Dividetheworkplaceintozonesthathavesimilarheatexposures.

Selectarepresentativelocationineachzonewhereyoucantakemeasurements.

How is heat stress measured?

TheMinistryofLabouruses“wetbulbglobetemperature”(WBGT)tomeasureheatstress.Thiscalculationtakesintoaccountairtemperature,radiantheatandhumidity.Exposurestandardsaredividedintocategoriesbasedonphysicalactivityandworkers’acclimatization.Adjustmentsaremadeforwearingtypesofclothingandpersonalprotectiveequipment.TakingWBGTmeasurementsproperlyrequiresspecializedequipmentandexpertise.Workplaceswithveryhotworkprocessesorwhereworkershaveexperiencedheat-relatedillnessesshouldmeasuretheWBGT.

Mostworkplacesdon’thave“hotprocesses”buthotweathercanposehealthriskstotheirworkers.Forthesehotworkenvironments,aHot Weather Planisappropriate.Thisisasimplifiedheatstresspreventionprogramandshouldestablishimplementationcriteria,or“triggers,”toputtheplanintoeffect.Criteriamayinclude:

Humidexreachingorexceeding35

EnvironmentCanadaHumidexadvisory(airtemperatureexceeding30ºCandHumidexexceeding40)orOntarioMinistryoftheEnvironmentsmogalert

Heatwaves(threeormoredaysoftemperaturesof32ºCormore)

Generally,HotweatherplansshouldbeinplacebetweenMay1andSeptember30.

ThistoolkitprovidesasimplifiedversionoftheWBGTbyconvertingitintoHumidexvalues.Itallowsworkplacestomeasureheatstressusingonlyworkplacetemperatureandhumidity.(SeeAppendixBonpage12formoredetails.)Thefollowingfivestepshelpdetermineactionstoreduceheatstress.

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Step � measure workplace temperature and humidity Usingathermal hygrometer(usually$20-$60athard-wareoroffice-supplystores),measurethetemperatureandrelativehumidityinyourworkplace.Avoidplacingthethermalhygrometerindirectsunlightorincontactwithhotsurfaces.

Onceyouhavethetemperatureandhumidity,besuretoadjustforclothing(Step2),andradiantheat(Step5).ThenusetheHeatstressawarenesstool(orthetableonpage13inAppendixB)todeterminetheappropriateheatstresspreventionresponse.

Formoredetailedcalculations(e.g.,foracclimatizedworkers),seeAppendixBonpage12orthecalculatorlocatedatwww.ohcow.on.ca/menuweb/heat_stress_calculator.htm.

Instructions for use of the heat stress awareness tool

1. Measuretheworkplacetemperatureandhumidity.

�. Turnthewheeltodisplaytheworkplacetemperature.Then,findthehumidityvalueontheleftaxis.Notethecolouroftheindicatedcell.

�. Refertothecolourontheinstructionchartforrecommendedaction.

Example: Ifthetemperatureis32°C(blackringinthewindow)andtherelativehumidityis50%,thecolourforthisrangeisyellow.Thisindicatesthattheprecautionsareinthe“moderate”valuerange.Inthiscase,therecommendedactionsare:

Furtherreducephysicalactivity Drinkacupofwaterevery15-20minutes

Note: The Heat stress action chart is based on workplace measurements, not weather station/media reports. (Temperatures inside buildings do not necessarily correspond with outside temperatures.)

Reduce Heat StressStep � Adjust for radiant heat Foroutdoorworkindirectsunlightbetweenthehoursof10a.m.and5p.m.,add1º-2º(prorateaccordingtopercentagecloudcover)toyourHumidexmeasurement.

Forindoorradiantheatexposures,useyourtraining,knowledgeandexperiencetojudgewhethertheexposureinvolvesmoreorlessradiantheatthandirectsunlightandadjustthe1º-2ºcorrectionfactorappropriately.

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Heat stress acclimatization Ontariosummersarenothotenoughforworkersdoinglightwork(sitting/standing,doinglightarmwork)tobeconsideredacclimatizedforWBGTpurposes.

WorkersdoingmoderateworkareonlyconsideredacclimatizedinOntarioiftheyregularlyworkaroundheatsources(e.g.,infoundries,aroundovens,etc.).SeeAppendixB.

WorkersperformingheavyworkacclimatizequicklyinOntario,butforthefirstwarmweatheroftheseason,morecautionisrecommended.EvenHumidex1(seepage13inAppendixB)maybetoohightoprotectfullyunacclimatizedworkersdoingheavywork.

Note: Clothing and radiant heat must be taken into account when using this guideline. See Steps 1 to 5 outlined on previous page.

managing heat stress

Nosystemcanaddressallsituations.Workplaceswithparticularsourcesofheatorhumiditymayneedextraassistanceindevelopingaheatstressresponseplan.TheHealthandSafetyAssociationslistedinAppendixEonpage18areanexcellentplacetostart.

Someworkplacesbeginwithrigoroussystemsofmeasurementandprescribedreactions,butonceinheatstressseason,workersandsupervisorseventuallylearntoanticipatewhenheatstresscontrols“kickin.”Insuchsituations,thesystembecomeslessformal.

Acoroner’sinquestintoacollegestudent’sdeathnotedthatprescribedresponsestothemeasurementsalonewillnotprotecteveryworker.Workersmustalsolearntolistentowhattheirbodiesaretellingthemandknowhowtorespondappropriately.Theheatstressresponseplanmustbeflexibleenoughtoprotectthemostvulnerableworkers.

Before establishing a policy, you must determine:

1. Oneormoremonitoringmethodsorcriteria(e.g.,self-regulation,Humidex,WBGTmeasurements).

2. Asamplingstrategy(e.g.,location,frequency,time,triggertostartmonitoring).

3. Responses(e.g.,rests,rotation,airconditioning,voluntarystayingonthejob,shutdown).

4. Training(when,howoften,content,length,JointHealthandSafetyCommitteeinvolvement,supervisors,workers,firstaid).

5. Water-supplycoordination(ensuringworkershavesufficientquantitiesofwateravailable).

6. First-aidreporting,emergencyresponse,medicalmonitoring,confidentiality.

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InworkplaceswithJHSCsorHealthandSafetyrepresentatives,itisimportanttogettheminvolvedandincorporatetheirideasintotheplan.TheHealthandSafetyAssociationsandtheWorkersHealthandSafetyCentrehaveresourcesavailabletoassistineducatingHealthandSafetyrepresentativesandJHSCmembersregardingthehazardsofheatstressandcontrols.

Oncethesebasicsareaddressed,youcanwriteyourpolicyandresponseplan.Asampleofaheatstresspolicycanbefoundonpage11,inAppendixA,alongwithaself-auditchecklistonpage14inAppendixC.Itiscrucialtothesuccessoftheplantogetuppermanagement’sendorsement.Oncetheplanisapproved,itneedstobecommunicatedandimplemented.Allprogramsneedtobeevaluatedtoensurethattheypreventheatstress.

Control measures

General control measures

Develop,communicateandimplementtheheatstressplanforallworkers.

Trainworkerstorecognizethesignsandsymptomsofheatstressandtoknowhowtoavoidthem.

Providewaternearbyonthejobsiteandensureeveryonedrinksaboutonecupofwaterevery20to30minutes,evenifthey’renotthirsty.

Establishafirst-aidresponsesystemwithtrainedfirst-aidprovidersandameanstorecordandreportheatstressincidents.

Allowtimeforworkerstoacclimatizetotheheatandthework.Thisusuallytakesabouttwoweeks.

MeasureHumidex(orWBGT)levelsandallowforself-limitationofexposure.(Ifthisisnotpossible,adjustthework/restcyclesaccordingly.)

Encourageworkerstouseabuddysystem—eachbuddylooksoutforearlysignsandsymptomsofheatstressintheother.

Job-specific control measures

Providebarrierstoshieldworkersfromradiantheatexposure.Providecoolingfanswhenairtemperatureisbelowskintemperature(35°C)and thehumidityisbelow70%.Considercoolingordehumidifyingtheworkplace.

Note: When the temperature exceeds 35°C and the relative humidity is above 70%, the use of fans will increase worker’s temperature because there will be little evaporation of sweat

Providemechanicalaidsformaterialhandling—dollies,carts,liftingdevices—toreducephysicalactivity.Organizetheworktoreducethepaceofactivity.

Ifpossible,postponestrenuousworkuntilacoolertimeoftheday.

Ifworkisdoneoutside,ensurethatshadedareasareavailable.

Rotateworkersinandoutofhotworkareaswheneverpossible.

Considercoolingvests,iffeasibleandeffectivefortheindividual.

personal control measures

Avoideatinglargemealsbeforeworkinginhotenvironments.

Avoidalcoholorbeverageswithcaffeine.Thesemakethebodylosewaterandincreasetheriskofheatstress.

Wearlightclothingthatpermitstheevaporationofsweat(e.g.,cottonclothing).Usesunscreenandcoveryourheadifworkingoutside.

Adviseworkerstocheckwiththeirdoctoriftheirmedicationmayaffecttheirheattolerance.

Makehealthylifestylechoices(i.e.,bodyweight,fitness,diet,rest,etc.)

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11


AppendixA

Heat stress policy (sample)

(Company name)

(Companyname)recognizesthepotentialproblemscausedbyhightemperaturesintheworkenvironment.Toreducethepotentialforheat-relatedillness,(Companyname)hasdevelopedthefollowingheatstresspolicy.

Thispolicyrequiresthefullcooperationofallmembersofthe(Companyname)team:Seniormanagement,theJointHealthandSafetyCommittee,supervisors,andworkers.Inordertomonitorandevaluatethepotentialforheat-relatedproblemsintheworkplace,areferenceguidecalledtheHeat Stress Awareness Guidewillbeused.Bylinkingtemperatureandhumidity,acolourcodeontheheatstressawarenesstool(asdescribedintheGuide)providestheappropriatework-siteresponse.

Employeesareaskedtocooperatefullywiththispolicy.Allemployeesof(Companyname)willbetrainedtorecognizethesignsandsymptomsofheatstress—inthemselves,aswellasinotheremployees.

Employeesexperiencingsymptomsofheatstressmustreporttofirst-aidpersonnelimmediatelytoobtainpropermedicalattention.Duringdayswhenheatstressproceduresareinplace,allemployeeswillfollowthecontingencyplans.Extrawaterwillbeavailableandworkerswillbeencouragedtodrinkit.

Inordertomonitortheeffectivenessofthispolicy,(Companyname)willperformanannualreview.Theheatstresspolicywillbeevaluated,improvementswillbemade,andacknowledgementwillbegiventothosewhomakesignificantcontributionstoitssuccess.

(Company manager) Date

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AppendixB

ThefollowingheatstressreferencechartshowsHumidexreadingsforthe2007ACGIHmoderateactionlevel(unacclimatized)workloadcategoryWBGTvaluesfromtheheatstress/strainTLV.SincetheMinistryofLabourheatstressguidelinesstatethat“hotspellsinOntarioseldomlastlongenoughforworkerstoacclimatize,”workersperforming“moderate”work(e.g.,workwithsomepushing,lifting)cannotbeassumedtobeacclimatizedunlesstheyareregularlyexposedtosignificantradiantheat.Workersperforming“heavy”work(e.g.,shovellingdrysand),however,couldprobablybeconsideredacclimatizedoncetheyareintothewarm-weatherseason.

Limitations:Thistableisbasedontheassumptionthattheworkisbeingperformedunderconditionswithlittleornoradiantheat,andworkerswearingregularsummerclothing;ifyourconditionsvaryfromthese,usethestepslistedonpages6and7tomakeadjustments.

Anonlineversionofthechartisavailablefordownloadatwww.ohcow.on.ca/menuweb/hhrplan.pdf

Anonlinecalculatorcanbeaccessedatwww.ohcow.on.ca/menuweb/heat_stress_calculator.htm

Heat stress reference chart

RELATIVE HUmIDITY (%)

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43 49 47 45 42 43

42 50 48 46 43 41 42

41 48 46 44 42 40 41

40 49 47 45 43 41 39 40

39 49 47 45 43 41 39 37 39

38 49 47 45 44 42 40 38 36 38

37 49 47 45 44 42 40 38 37 35 37

36 50 49 47 45 44 42 40 39 37 35 34 36

35 50 48 47 45 44 42 40 39 37 36 34 33 35

34 49 48 46 45 43 42 40 39 37 36 34 33 31 34

33 50 48 47 46 44 43 41 40 39 37 36 34 33 32 30 33

32 50 49 48 46 45 44 42 41 40 38 37 36 34 33 32 30 29 32

31 50 49 48 47 45 44 43 42 40 39 38 37 35 34 33 32 30 29 28 31

30 48 47 46 44 43 42 41 40 39 37 36 35 34 33 32 30 29 28 27 30

29 46 45 43 42 41 40 39 38 37 36 35 33 32 31 30 29 28 27 26 29

28 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 28

27 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 27

26 39 38 37 36 35 34 34 33 32 31 30 29 28 27 26 25 26

25 37 36 35 34 34 33 32 31 30 29 28 27 27 26 25 25

24 35 34 33 33 32 31 30 29 28 28 27 26 25 24

23 33 32 32 31 30 29 28 28 27 26 25 23

22 31 30 30 29 28 27 27 26 25 25 22

21 29 29 28 27 27 26 25 21

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Humidex 1 or Humidex �

TherearetwoHumidexguidelinestodeterminetheappropriateactionsrequired:

Humidex 1referstounacclimatized workersdoing“moderate”work,andrangesindicatetheneedforgeneral heat stress controls.

Humidex � referstoacclimatized workersdoing“moderate”work,andrangesindicatetheneedforspecific controls.

TheACGIHspecifiesanactionlimitandaTLVtopreventworkers’bodytemperaturesfromexceeding38°C(38.5°Cforacclimatizedworkers).Belowtheactionlimit(whichcorrespondstoHumidex1forworkofmoderatephysicalactivity),mostworkerswillnotexperienceheatstress.Mosthealthy,well-hydrated,acclimatizedworkersnotonmedicationwillbeabletotolerateheatstressuptotheTLV(Humidex2formoderatephysicalactivity).

nEVER IGnoRE AnyonE’S SympTomS, REGARDLESS oF youR mEASuREmEnTS!

Note: Clothing and radiant heat must also be taken into account when using this guideline (See Steps 1 to 5 outlined on pages 6 and 7).

Humidex 1 general controls ACTION RECOmmENDED

Humidex � specific controls

�0 – �� Warnforsymptomsandextrawater �� – ��

�� – �� Workwith15minutes/hourrelief �� – ��

�0 – �1 Workwith30minutes/hourrelief �� – ��*

�� – �� Workwith45minutes/hourrelief �� – ��*

��+ Hazardoustocontinuephysicalactivity �0+*

*ForHumidexrangesabove45,heatstressshouldbemanagedaspertheACGIHTLV

Humidex 1 general controlsincludeprovidingannualheatstresstraining,encouragingadequatefluidreplacement,permittingself-limitationofexposure,encouragingemployeestowatchoutforsymptomsinco-workers,andadjustingexpectationsforworkerscomingbacktoworkafteranabsence.

Humidex � specific controlsinclude(inadditiontogeneralcontrols)engineeringcontrolstoreducephysicaljobdemands,shieldingofradiantheat,increasedairmovement,reductionofheatandmoistureemissionsatthesource,adjustingexposuretimestoallowsufficientrecovery,andpersonalbody-coolingequipment.

Example:Supposethetemperatureintheworkplaceismeasuredat��°C andtherelativehumidityis�0%.TheHumidex wouldbe�1(seeheatstressreferencechart,page12).

Therefore,recommendedactionisasfollows:

Humidex 1: 30minutes/hourrelief,and;

Humidex �:Fullwork,withwarningtobewaryofheatstresssymptomsandtodrinkextrawater.

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LEADERSHIp Writtenheatstresspolicyandplan

Responsibilitiesandaccountabilitiesidentifiedfor:

Employer

Supervisor

JHSC/H&Srepresentative

Worker

EmpLOYEE TRAINING Forallrelevantpersonnel

Whatisheatstress?

Symptomsandhealtheffects

Personalriskfactors

Jobsatrisk

Monitoringresults

Actionstobetakenforcontrollingheatstress

Heatstresspolicyandplan

Controlsasestablished—engineering,administration,workpractices

Personalprotectiveequipment

Firstaid

Reportingprocedures

Medicalsurveillance

Aself-auditcandeterminewhatmechanismsandpracticesyourworkplacehasinplacetocombatheatstress.Italsoindicateswhichprogramsorpracticesmaybedeficientandrequireattention.

AppendixC

The self-audit checklist

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STANDARDS & pROCEDURES

Identificationofpotentialheathazardsandjobsatrisk

Visualobservations

Accident/incidentreports

Absenteerate,employeecomplaints,medicalrecords

Assessmentandevaluationofrisk

mONITORING Weatherasatrigger

Typeoftesting

Frequency

Workloadcategoriesforjob

Clothinginsulationvalues

Comparisonofmonitoringresultstoacceptablestandards

CONTROLS Controls(e.g.,shieldingheatsources,ventilation,fans, airconditioning,reducingmetabolicworkload,acclimatization, workscheduling,rotation,work/restregimen,water,personal protectiveequipment)

Evaluationofoverallprogrameffectiveness

Compliancewithstandardsandprocedures

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AppendixD

Essentials for a successful heat stress prevention program

The following elements are important in making your heat stress prevention program successful:

CommunicationTheorganizationshouldcommunicatetherequirementsofallheatstressstandards,policies,andprocedurestoallemployees.

Training and personnel developmentEmployeesmayneedtrainingonsuchtopicsas:

Definitionofheatstress

Signsandsymptomsofheat-relateddisorders

Importanceofreportingsignsandsymptomstosupervisors

When,how,andwhytotakebreaksfromhotwork

Recognition,assessment,andevaluationofheatstress

Controlsforheatstress

measurementTheorganizationshouldkeeptrackofdatathatcanprovideanevaluationoftheheatstresspreventionprogram.Forexample,youshouldkeeptrackoflost-timeinjuriesduetoheatandhotweatherconditions,workercomplaintsofdiscomfortafterprolongedwork,andpurchasesofequipmentmeetingstandardsthathavebeenset.Youmaywanttorepeataneedsassessmentoraheatsurveydoneearliertogetcomparativedataaftercontrolshavebeenputinplacetocheckifthecontrolsareadequate.

Leadership commitmentManagementmustrecognizethataheatstresspreventionprogramisrequiredtopreventheatstress,andmustshowcommitmenttoaheatstresspreventionprogramthroughappropriateassignmentofresources.Employeesmustbeinvolvedateverystepoftheprogram’sdevelopmentandimplementation.

Identifying hazards, assessing risk, and determining needsTheorganizationmustperformanddocumentanassessmenttoidentifyallriskfactorsintheworkplacethatcouldleadtoheatstress.Considerationshouldbegiventolegislativerequirements,industrybestpractices,internallost-timedata,etc.Toolstoperformthisassessmentcouldincludewalk-throughinspections,surveys,checklists,andtaskanalysis.Theseassessmentsshouldberepeatedperiodically,orasoftenasprocessesintheorganizationchange.

Implementation of the plan and strategyOncetherisksandneedshavebeenidentified,theorganizationshoulddevelopaplantoaddressthem.Theplanshoulddefineresponsibilities,accountabilities,timelines,andmilestonesforimplementingtheplan.

StandardsTheorganizationshouldestablishanddocumentitsstandardsforheatstressprevention,consideringguidelinesfromprofessionalbodies,industrybestpractices,etc.

procedures, guidelines, and practicesProcedures,guidelines,andpracticestoimplementallidentifiedheatstresspoliciesandstandardsmustbedocumented.Theyshoulddefine,stepbystep,theprocesstoaccomplishataskoractivity,includingwork/restregimes(howoften,when,inwhatareas,etc.),asdefinedinthestandards.

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EvaluationTheorganizationshouldanalyzethemeasurementdatatodeterminethedegreeofcomplianceandeffectivenessoftheheatstresspreventionprogrambylookingatindicatorssuchas:

Reductioninheat-relatedsymptomsandillnessthroughimplementationofcontrols

Reductioninabsenteeismorlosttimerelatedtoheat

Increaseinworkers’knowledgeaboutheatstressrecognitionandprevention

Decreaseincomplaintsofdiscomfort

Adherencetowork/restregimensonhotdays

Recognition, improvement, correctionDevelopanimprovementplanbasedonthemeasurementandevaluationfindings,andincludeopportunitiesforimprovementandcorrection.Ifyouensurethatallcomponentsofthiscontinuous-improvementloopareinplace,youwillincreasetheeffectivenessofyourheatstresspreventionprogram.

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AppendixE

Research and support

TechnicalsupportisavailablefromyourHealthandSafetyAssociation.Workplace-specificinformation,aswellastrainingandconsultingservicesforillnessandinjuryprevention,areprovidedbytheHealthandSafetyAssociationsofOntario,theWorkersHealthandSafetyCentre,andtheOccupationalHealthClinicsforOntarioWorkers.

OntarioMinistryofLabourwww.labour.gov.on.ca

InstituteforWorkandHealthwww.iwh.on.ca

WorkplaceSafetyandInsuranceBoardwww.wsib.on.ca

ConstructionSafetyAssociationofOntariowww.csao.org

EducationSafetyAssociationofOntariowww.esao.on.ca

Electrical&UtilitiesSafetyAssociationwww.eusa.on.ca

FarmSafetyAssociationwww.farmsafety.ca

IndustrialAccidentPreventionAssociationwww.iapa.ca

MinesandAggregatesSafetyandHealthAssociationwww.masha.on.ca

MunicipalHealthandSafetyAssociationwww.mhsao.com

OntarioForestrySafeWorkplaceAssociationwww.ofswa.on.ca

OntarioSafetyAssociationforCommunityandHealthcarewww.osach.ca

OntarioServiceSafetyAlliancewww.ossa.com

Pulp&PaperHealthandSafetyAssociationwww.pphsa.on.ca

TransportationHealth&SafetyAssociationofOntariowww.thsao.on.ca

WorkersHealth&SafetyCentrewww.whsc.on.ca

OccupationalHealthClinicsforOntarioWorkerswww.ohcow.on.ca

Other sources of information on heat stress include:

HealthCanadawww.hc-sc.gc.ca

OccupationalSafetyandHealthAdministration(USA)www.osha.gov/SLTC/heatstress/recog nition.html

For information on humidity, weather reports, and smog alerts:

EnvironmentCanadawww.msc.ec.gc.ca

EnvironmentCanadafactsheet:summersevereweatherwww.on.ec.gc.ca/severe-weather/summer.html

OHCOWHumidex-basedheatstresscalculatorwww.ohcow.on.ca/menuweb/heat_stress_calculator.htm

EnvironmentCanadaHumidexcalculatorlavoieverte.qc.ec.gc.ca/meteo/Documentation/Humidex_e.html

EnvironmentCanadaweatherofficewww.weatheroffice.ec.gc.ca/canada_e.html

AirQualityOntariosmogadvisorieswww.airqualityontario.com

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AppendixF

Environment Canada contacts

EnvironmentCanadaprovidesregionalweatherdetailsandforecastsviatheserviceslistedbelow:

www.weatheroffice.ec.gc.ca

EnvironmentCanada(toll-freeat1-�00-��-��)foroptionstoobtainthelatestweatherconditionsandforecastforyourlocation.

Asof2008:Dial�11foraccesstothelatestweatherandroadconditions,anywhereinCanada,viaatouch-tonephone.


5252A CSAO (04/07) © 2007, WSIB Ontario. Printed in Canada


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HEAT STRESS AWARENESS TOOL & POSTER

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OHSCO Heat Stress Awareness Guide

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