Students Will Beintroducedto the Potential Hazards Ofworkingwith Compressedairandhow

CompressedAir

Description

Students will beintroducedto the potential hazards ofworkingwith compressedairandhow toappreciatethebenefitsofair-operatedtools.Studentswillalso be shownthesafeandproperoperationofairtools.

LessonOutcomes

The student willbeableto:

•Recognizeand understand thedangersand the safeuse ofcompressedair

•Recognizethebenefitsofusing compressed airtoolsover electrical or handtools

•Describe theoperationanduseofseveral commonly usedair-operatedhandtools

•Connect anddisconnect a varietyofairtoolstoanairsupply

•Describe the correct proceduretomaintainairtools connectors andtheairsupply

Assumptions

•Studentshave little or nopreviousknowledge or skillintheuseof compressed airtools.

•Theteacherhaspreviouslyusedairtoolsandhas a good workingknowledgeofair-operatedtools.

EstimatedTime

Sixtyminutes if the lesson isdividedintothree 20-minute sessionsconsistingof(1)explanation,

(2)demonstrationand(3)student practice time

RecommendedNumberofStudents

20, based on the BCTechnologyEducators’Best Practice Guide, preferably workingin pairs(willdepend on theavailabilityofequipment)

Facilities

Anyshopfacilitywith compressed available

Tools

•Sufficient airhoseswith connectors foreachpairofstudents if possible.Ifnot,thenstations can be madewith a shortlengthofhoseand a connector installed.Thiswillallowstudents topractiseconnecting anddisconnectingdifferent airtools despitethemnotbeingconnectedtoanairsupply.

•As manydifferent types ofairtoolsas can be locatedtodemonstratetheiruseandpurposetothestudents.

•An“airgun”(impactwrench),airdrill,air/diegrinder,airhammer/chiseland a “blow gun”should be theminimumsetoftoolsavailablefordemonstration.Additionaltoolswould beanasset.

Figure1—Impactwrench

Figure2—Diegrinder

Figure3—Airdrill

Figure4—Airratchet

Figure5—TIreinflator

Figure6—Aircutter

Figure7—Airblowgun

Figure8—Airchisel

Materials

•“CleaningwithCompressedAir”handoutforeachstudent,listingthedangersofusinghigh-pressureair(see“Resources”section).

•Safetyglasses

•Sufficient airhoseswith connectors foreachpairofstudents if possible.Ifnot,thenstations canbemade withashort length of hose with a“female” connector installed forstudentstopractise connecting anddisconnectingdifferentairtools.

•A sufficient amountandvarietyofairtools(listedinthe“Tools”section)andattachmentsforstudentsto be abletolearnall types oftoolsandhowthey connect andoperate.

Resources

“CleaningwithCompressedAir.”CanadianCentreforOccupationalHealthandSafety

Demonstration

1.Beginwithanexplanationofhowairisdeliveredtotheshop.Showthestudentsthelocation oftheairsupply(compressor).

Figure9—Aircompressor

2.Ensure access ispossibleforallstudents, or have a portable unitavailableforthedemonstration.Showthe start-up procedureasexplainedintheowner’smanualandfollowupwiththescheduledmaintenance described inthesamemanual.Thiswillinclude

checkingtheairfilter,crankcaseandoillevelandalsodrainingthetankdailytoensurethatnocondensationhasbuiltupinsidetheairtank, which could otherwise leadtorusting.

3.Describe anddemonstratethe connection ofairfittings. Describe therelationshipandhowto identify “male”and“female”connectors.Demonstratehowtorecognizefaultyairhosesand connectors byshowing poorly installedconnectors,andcut or leakinghosesandfittings.

Activity

1.Startwithanexplanationofthe types ofair fittings attached toanairhose. Describe andexplaintheuseof“male”and“female”terminologyinrelationtoshoptoolsandequipment.

Figure10—Femalecoupler / Figure11—Malecoupler

2.Havestudentsobtainsafetyglassesanddemonstratetheneedforglasseswhenconnecting anddisconnectinganairlinetoitssupplyconnector,especiallyateyelevel.

3.Handout a copyof“CleaningwithCompressedAir”toeachstudentandhavethemreadalongwhileexplainingthedangersofhigh-pressure compressed air.Anopendiscussionshould be promptedtoraiseanyadditionalquestionsthatmaypromotesafetyawarenessamongallstudents.Lead a discussion on whereairtoolsshould be used(e.g.,wherethereisnoavailable electrical power or inanexplosiveenvironment).

4.Havestudents work inpairsto connect anddisconnecttoolsand fittings toan“uncharged”airlinetolearnthe process.

5.Demonstrateandthenhavestudentsoperatethe forward andreversefunctionoftoolssuchasairdrills,impactwrenchesandratchets.

6.Havestudents work inpairsto connect anddisconnectseveralairtoolsto a “live”airsupplylineand become comfortable withthetools’operation.

7.Showthestudentshowto coil theairhoseinthe correct mannerbymakingaslong a loopasis practical tohang on a hook on thewall.Tohelpthehose coil properly,demonstratehowto“rotate”thehoseaway from youto form thecoil,inmuchthesamewayas a rope iscoiled.Havethestudentstrydoingthe coil withthehose connected totheairsupplyandagainwhenit’snotconnected,toseehowmucheasieritiswhenit’sdisconnected.

8.Explain theneedforsafetyglasses or shieldswhenusing a blowgunandundamagedcutterwheels,andexplaintheneedforguards on air/diegrinders.

CleaningwithCompressedAir

Isitagoodideatousecompressedairtoblowdirtoffclothingorworksurfaces?Iscleaningwithcompressedairallowedbylaw?

Whatarethehazardsofusingcompressedair?

WhatshouldIuseinsteadofcompressedairforcleaningpurposes?Wherecompressedairisallowedforcleaning,howcanIdoitsafely?

Isitagoodideatousecompressedairtoblowdirtoffclothingorworksurfaces? No.Althoughmany people knowusing compressed airto clean debris or clothes can behazardous,itisstillusedbecauseof old habitsandtheeasyavailabilityof compressed airin

manyworkplaces.However,cleaningobjects,machinery,benchtops,clothingandotherthingswith compressed airisdangerous.Injuries can be causedbytheairjetandby particles madeairborne (re-entertheair).

Iscleaningwithcompressedairallowedbylaw?

InmanyCanadianjurisdictions,cleaningwith compressed airisnotallowedbylaw. Alberta,Newfoundland, Prince EdwardIsland,QuebecandSaskatchewan specifically mentionthatcompressed airshallnot be usedto clean clothes, or inothersituationscleaning a person,machinery,work benches, etc.Reference to cleaning may also be included with specific mentiontoitbeingprohibitedwhenthereis a risk totheworkerbeinginjured(federalregulations,

Ontario,BritishColumbia,NorthWestTerritories,NunavutandtheYukon).

In some cases,otherlegislationmayapply.Forexample,cleaningwith compressed airisprohibitedinManitobaand Ontario whenworkingwithasbestos.

Always check withyourjurisdictionformoreinformation.

Whatarethehazardsofusingcompressedair?

First, compressed airisextremelyforceful.Depending on itspressure, compressed air candislodge particles. These particles are a dangersincethey can enteryoureyes or abradeskin.Thepossibledamagewoulddepend on thesize,weight,shape, composition andspeedofthe particles. Therehavealsobeen reports ofhearingdamagecausedbythepressureofcompressed airandbyitssound.

Second, compressed airitselfisalso a serioushazard. On rareoccasions, some ofthecompressed air can enterthe blood streamthrough a breakintheskin or through a bodyopening.Anairbubbleinthebloodstreamisknownmedicallyasanembolism, a dangerousmedical conditioninwhich a blood vesselisblocked,inthiscase,byanairbubble.Anembolismofanartery can cause coma, paralysis or deathdependinguponitssize,durationandlocation.

Whileairembolismsareusuallyassociatedwith incorrect divingprocedures,theyarepossiblewith compressed airduetohighpressures.Whilethisseemsimprobable,theconsequencesofeven a smallquantityofair or othergasintheblood can quickly be fatal.

Inaddition,usingairto clean forces thedirtanddust particles intotheair,makingthesecontaminants airborne andcreating a respiratoryhazard.

Unfortunately,horseplayhasbeen a causeof some seriousworkplaceaccidentscausedbyindividualsnotawareofthehazardsof compressed air, or proper work procedures.

WhatshouldIuseinsteadofcompressedairforcleaningpurposes?

Usewetsweepingtechniques,sweepingcompounds, or vacuumcleanersequippedwithspecialfilters or otherdevicestopreventdust from beingrecirculatedintotheair.

Wherecompressedairisallowedforcleaning,howcanIdoitsafely?

A “quiet”nozzle(i.e.onewithlownoiseemission)should be selected.

Thenozzlepressuremustremainbelow10psi(69 or 70kPa)andpersonalprotectionequipment(PPE)must be worn toprotecttheworker’sbody,especiallytheeyes,againstparticles anddustunderpressure.

Note: Air pressureislegislatedbyNewBrunswick(69kPa),Yukon (69kPa/10psi)and

where permitted underfederal(69kPa/10psi),BritishColumbia(70kPa/10psig),NorthWestTerritories and Nunavut (68.9 kPa/10 P.S.I.) legislation.

TheNova Scotia regulationstates:

101.(2)Where compressed airisusedto clean a surface or person,anemployershallensurethatthedevicethatisusedtodelivertheairis

(a)commerciallymanufacturedandapprovedinthemanufacturer’s specifications forthepurposeofcleaning asurfaceor person with compressedair; or

(b)certifiedbyanengineerasadequateforthepurposeofcleaning a surface or person withcompressed air.

OccupationalSafetyGeneralRegulationsN.S.Reg.44/99 Section 101Ontario doesnot specify a pressurelimitbutdoesstate:

66. A compressed air or other compressed gasblowingdeviceshallnot be usedforblowingdust or othersubstances,

(a)from clothing worn by a workerexceptwherethedevicelimitsincreaseinpressurewhenthenozzleisblocked; or

(b)insuch a mannerastoendangerthesafetyofanyworker.IndustrialEstablishmentsR.R.O.1990,Reg.851

Inaddition,airgunsshouldalso be usedwith some local exhaustventilation or facilitiestocontrol thegenerationof airborne particulates.When compressed aircleaningisunavoidable,hazards can be reducedbymakingadjustmentstotheairgunsuchas:

•chipguards or curtains that can deflect flyingdust or debris,

•extensiontubesthatprovidetheworker a saferworkingdistance, or

•airgunsequippedwithinjectionexhaustsand particle collection bags.

DocumentlastupdatedonApril7,2010

CleaningwithCompressedAirQuiz

Instructions:Readthe“CleaningwithCompressedAir”handoutandanswerthefollowingquestions.

1.Explain how compressed airisproducedanddeliveredtoshopoutlets.Answerwill vary depending on facility.

2.Listtwo important safety rules torememberwhenusing compressed airtools.Alwaysweareyeprotection.

Neverblowairatexposedskin.

3.Givetwoexamplesofwhenair-operatedtoolsaremoresuitablethan electrical tools.A flammableenvironment

Mainpowerisnotyetinstalledto a newbuilding.

4.Whyshouldanair compressor storagetank be draineddaily?Tostoptheinsideofthetank from rusting from condensation.

5.If compressed airMUST be usedtoblowoffmachinery,whatisthemaximumpressure?10poundspersquareinch(PSI).