Authorized Entrant Means an Employee Whois Authorized Bythe Employertoenter a Permit Space

ConfinedSpaceDefinitions

OSHAStandard 1910.146

Acceptableentryconditions means the conditions that must exist in apermit spacetoallowentryandtoensurethat employees involved withapermit-required confinedspace entrycan safelyenter into and work within thespace.

Attendantmeans an individual stationedoutside oneor more permit spaces who monitors the authorizedentrants and whoperforms all attendant's duties assignedin the employer's permitspace program.

Authorized entrantmeans an employee whois authorized bythe employertoenter a permit space.

Blankingor blindingmeans the absoluteclosureofapipe, line, or duct bythefasteningofasolid plate(suchasa spectacleblindor a skillet blind)thatcompletelycovers thebore andthat is capableof withstandingthe maximumpressure ofthepipe, line,or ductwithno leakagebeyond theplate.

Bodilyentermeans the actionbywhich apersonpasses through an openingintoapermit-required confinedspace.Entryincludes ensuing work activitiesinthat spaceand is consideredtohaveoccurredas soon as anypart ofthe entrant's bodybreaks the planeofanopening intothe space.

Confinedspace means aspace that:

1.Is large enoughandsoconfigured thatanemployeecanbodily enter and performassignedwork; and

2.Has limitedorrestricted means for entryor exit(forexample, tanks, vessels, silos, storage bins, hoppers,vaults,andpitsare spaces that mayhavelimited means ofentry.);and

3.Is notdesignedforcontinuousemployeeoccupancy.

Designed for continuousworkeroccupancyIntended as a placeof regular work and suppliedwithventilationandother conditions necessaryto supportlife

Doubleblockandbleedmeans the closureofaline, duct,or pipeby closingandlockingortaggingtwoin-linevalvesandbyopeningand lockingortaggingadrain orvent valvein theline betweenthe two closed valves.

Emergencymeans anyoccurrence (includinganyfailure ofhazard control ormonitoringequipment) or eventinternal orexternal tothe

permitspace thatcouldendanger entrants.

Engulfmentmeans the surroundingandeffectivecaptureofaperson byaliquid orfinelydivided(flowable) solid substancethat canbe aspirated to causedeathbyfillingorpluggingthe respiratorysystem or that can exert enough force on the bodyto causedeathby strangulation, constriction, orcrushing.

Entrymeans the actionbywhich apersonpasses through an opening intoapermit-required confinedspace.Entryincludes ensuingwork activities inthat spaceandis consideredto have occurredas soonas anypart ofthe entrant's bodybreaks the planeofanopeningintothe space.

Entrypermit (permit)means the written orprinteddocument that is providedbythe employertoallowand control entryintoapermit space andthat contains the informationspecifiedbytheOSHA Standard.

Entrysupervisor means the person (suchas the employer,foreman, or crewchief) responsiblefordeterminingifacceptableentry conditions are present at apermitspacewhereentryis planned,for authorizingentryand overseeingentryoperations, and for terminating entryasrequiredbythis section.

NOTE: Anentrysupervisoralso mayserveas an attendantoras an authorized entrant, aslongas that person is trained andequipped as

requiredbythis section for eachroleheor shefills. Also,theduties of

entrysupervisor maybe passed fromoneindividual to anotherduring the courseofanentryoperation.

Hazardousatmosphere means an atmospherethat mayexpose employees tothe risk ofdeath,incapacitation,impairmentofabilityto self-rescue(that is, escape unaidedfroma permit space),injury, or acuteillness fromone ormoreofthe followingcauses:

1.Flammablegas,vapor, ormistin excess of10percent ofitslower flammable limit(LFL);

2.Airbornecombustible dustat aconcentration that meetsor

exceedsitsLFL; NOTE: Thisconcentrationmaybeapproximated asa condition inwhichthedust obscures vision at adistanceof5 feet(1.52 m) or less.

3.Atmospheric oxygenconcentration below19.5percentor above

23.5percent;

4.Atmospheric concentrationofanysubstanceforwhicha doseora permissibleexposurelimit is publishedinSubpart G,Occupational Health andEnvironmental Control,or inSubpart Z,Toxicand Hazardous Substances, ofthis Partand which couldresultin employee exposure inexcess ofitsdoseor permissibleexposure limit;NOTE: Anatmospheric concentration ofanysubstance that is not capable ofcausingdeath,incapacitation,impairmentof

abilitytoself-rescue,injury, oracuteillness dueto itshealth effects is not coveredbythisprovision.

5.Anyother atmospheric conditionthat is immediatelydangerous to lifeor health.NOTE: For aircontaminantsforwhich OSHAhas not

determined adose orpermissible exposure limit,other sources of information,suchas Material SafetyDataSheets thatcomplywith

theHazard CommunicationStandard, published information, and other documents canprovide guidance inestablishingacceptable atmospheric conditions.

Hot work permit means the employer's writtenauthorizationto performoperations (forexample, riveting, welding,cutting, burning, and heating)capable ofprovidinga sourceofignition.

Immediatelydangerousto lifeor health(IDLH)means any conditionthat poses animmediateordelayedthreat tolifeorthat wouldcauseirreversible adversehealtheffects orthat wouldinterfere withanindividual'sabilitytoescape unaidedfroma permit space. NOTE: Some materials --hydrogen fluoridegas andcadmiumvapor, forexample -- mayproduceimmediatetransient effects that, evenif severe, maypass without medical attention,butarefollowed by sudden, possiblyfatal collapse12-72hoursafter exposure.Thevictim

"feels normal"fromrecoveryfromtransient effects until collapse. Such materials in hazardous quantitiesareconsidered to be "immediately"

dangerous tolife orhealth.

Inertingmeans the displacement oftheatmosphere ina permit space byanoncombustiblegas (such as nitrogen)tosuchanextent thatthe resultingatmosphereis noncombustible. NOTE: Thisprocedure produces an IDLH oxygen-deficientatmosphere.

Isolation means the process bywhich apermitspace is removed fromserviceandcompletelyprotectedagainst the releaseofenergy and material into thespacebysuch means as: blankingorblinding; misaligningor removingsections oflines, pipes, orducts;a double block and bleedsystem; lockout ortagout ofall sources ofenergy;or blockingor disconnectingall mechanical linkages.

Limited or restricted means for entryor exitAnyspacewherean occupant mustcrawl, climb, twist, beconstrainedin anarrowopening, followa lengthypathor otherwiseexert unusual effortto enteror leave, or wheretheentrance maybecomesealed orsecured against openingfrominside.

Linebreaking means the intentional openingofapipe, line,or duct that is orhas beencarryingflammable, corrosive,ortoxic material,an inert gas, or anyfluidat avolume,pressure, or temperaturecapable ofcausinginjury.

Non-permitconfinedspace means aconfined spacethat doesnot containor,withrespectto atmospheric hazards, have the potential to containanyhazardcapableofcausingdeath orseriousphysical harm.

Oxygendeficientatmosphere means an atmospherecontainingless than19.5 percent oxygenby volume.

Oxygenenriched atmospheremeans an atmospherecontaining morethan 23.5percent oxygenby volume.

Permit-required confined space(permit space)means aconfined space thathas one ormoreofthe followingcharacteristics:

1.Containsorhas apotential tocontaina hazardous atmosphere;

2.Containsa material thathasthepotential forengulfingan entrant;

3.Has an internal configuration such thatanentrant could be trapped or asphyxiatedbyinwardlyconvergingwalls or byafloorwhich slopes downward andtapersto asmallercross-section;or

4.Containsanyother recognizedserious safetyorhealth hazard.

Permit-required confined spaceprogram(permitspace program) means the employer's overall programforcontrolling, and,where appropriate,forprotectingemployees from,permit spacehazards and forregulatingemployee entryinto permit spaces.The measures necessaryforsafeentry intoonepermitspace, ortypeofspace, may differfromthoserequiredforotherspaces. The implementation ofa generic programthat fails toconsider theunique characteristicsofa particularpermitspace could have catastrophic consequences. The permitspace programmust address each permit spaceso that entrants receive appropriateprotection.

Permitsystemmeans the employer's writtenprocedureforpreparing

andissuingpermits forentryandfor returningthe permit spaceto servicefollowingtermination ofentry.

Prohibitedconditionmeans anyconditionin apermitspacethat is not allowedbythe permit duringtheperiodwhen entryis authorized.

Rescueservice means the personnel designatedto rescue employees frompermit spaces.

Retrieval systemmeans the equipment (includinga retrieval line, chest orfull-bodyharness, wristlets, ifappropriate,andaliftingdevice or anchor)used for non-entryrescueofpersons frompermitspaces. Theretrieval system must be available, meaningthat theentrant's retrieval lineis attached to a mechanical devicesothat rescuecan begin as soon as therescuer becomes aware thatrescue is necessary.

Testingmeans the process bywhich thehazards that mayconfront entrants ofa permit space areidentifiedand evaluated.Testing includes specifyingthetests that are to be performedin thepermit space.NOTE: Testingenables employers bothtodeviseand implementadequatecontrol measures forthe protectionofauthorized entrants andtodetermineifacceptableentryconditions arepresent immediatelypriorto, andduring, entry.