2 Objectives Understand Legislation Developed by Government Agencies Identify and Use Those RegulationsIdentify a Potentially Hazardous Confined Space
3 Organizations ANSI NIOSH American National Standards Institute Consensus Standards for Atmospheric HazardsNIOSHNational Institute for Occupational Safety and HealthDocuments IncidentsDevelops Guidelines for Safe Work
4 Organizations (continued) OSHAOccupational Safety and Health AdministrationBegan Looking at Confined Spaces in 1975Cited Under General Duty ClauseProposed Standard Released June 1989
5 Permit-Required Confined Spaces 29 CFR 1910.146 Became Law April 15, 1993Employers MUSTCharacterize the Confined SpaceProvide a Permit Allowing EntrySupply Personal Protective Equipment When RequiredExcludes Agriculture, Construction, and Shipyards
6 Permit-Required Confined Spaces 29 CFR 1910.146 A Confined Space is...Large Enough and Configured Such That an Employee Can Enter and Perform Assigned WorkHas Limited or Restricted Means for Entry or Exit (e.g., Tanks, Vessels, Silos, Storage Bins, Hoppers, Vaults, and Pits)Is Not Designated for Continuous Employee Occupancy
8 Permit-Required Confined Spaces 29 CFR 1910.146 A Permit-Required Confined Space...Contains or Has Potential to Contain a Hazardous AtmosphereContains a Material That Has the Potential for EngulfmentInternal Configuration of Inwardly Converging Walls or Sloping and Tapering FloorContains Any Other Recognized Serious Safety or Health Hazard
9 Permit-Required Confined Spaces 29 CFR 1910.146 Engulfment...Surrounding and Capture of a PersonLiquid or Finely Divided (Flowable) SolidCan Cause Filling or Plugging of Respiratory System Via AspirationCan Exert Enough Force on Body to Cause Death by Strangulation, Constriction, or Crushing
10 Permit-Required Confined Spaces 29 CFR 1910.146 Immediately Dangerous to Life or Health (IDLH)...Immediate or Delayed Threat to LifeCauses Irreversible Adverse Health EffectsInterferes With the Ability to Escape from a Permit Space
11 Permit-Required Confined Spaces 29 CFR 1910.146 IDLH Conditions...Flammable Gas, Vapor, or Mist >10% of LFL (LEL)Airborne Combustible Dust > LFLDust Obscures Vision at a Distance of 5 ft. or lessOxygen < 19.5 % or > 23.5%Exposures in Excess of OSHA’s PELs
12 Employer’s Responsibilities Determines Whether Permit-Required Confined Spaces Exist(Appendix A - Flow Chart)Informs Employees and Posts Warning SignsPrevents Entry If Employees are Not to Work in PRCS
13 Employer’s Responsibilities (continued) Develop and Implement a Written Permit Entry ProgramMay Use Alternate ProceduresIf a Non-Permit Space is Reconfigured, Re-evaluation of the Space is RequiredMust Inform Contractors and Use Permitting Program
16 Permit-Required Confined Space ELEMENTS OF THE PROGRAM Prevent Unauthorized EntryIdentify and Evaluate the Hazards Prior to Entry (Appendix B- Who Can Do This, & How)Develop Safe Entry ProceduresAcceptable Entry ConditionsIsolating the Permit SpacePurging, Inerting, Flushing, or VentilatingBarriers to Protect from External Hazards
17 Permit-Required Confined Space (PRCS) EquipmentTesting and Monitoring EquipmentVentilating EquipmentCommunications EquipmentPersonal Protective Equipment
18 Permit-Required Confined Space (PRCS) Equipment (continued)LightingBarriers and ShieldsLadders and Other Entry/Egress EquipmentRescue and Emergency Equipment
19 Permit-Required Confined Space ELEMENTS OF THE PROGRAM (continued) Evaluate Space Before and During WorkProvide at Least One Attendant Outside for the Duration of Entry OperationsMultiple Space Response ProceduresDesignate Active RolesRescue and Emergency Response Procedures
20 Permit-Required Confined Space ELEMENTS OF THE PROGRAM (continued) System for Preparation, Issuance, Use and Cancellation of PermitsProcedures for Multiple Employer WorksitesProcedures for Closing SpaceReview of Entry OperationsReview of Program
21 Permit-Required Confined Space (PRCS) Permit SystemEntry PermitTrainingOther AppendicesAppendix C: Example SituationsAppendix D: Example Check List & PermitAppendix E: Sewer System Entry
22 Permit-Required Confined Space The Permit 1. DATE:____ TIME:____ A.M../P.M VESSEL # JOB # LOCATION:5.DESCRIPTION OF WORK:6.PHYSICAL HAZARD ASSESSMENT: Engulfment, Electrical, Steam, Augers, Chain Drives etc..7. CORRECTIVE MEASURES: Physical Disconnects, Lockout / Tagout etc..8. ATMOSPHERIC ASSESSMENT: Oxygen, LEL, CO, H2S (Other)9. Instrument # 10. Calibration Date: 11. Name of Operator:12. Substance 13. P.E.L Actual15. Oxygen 16. < 19.5% or > 23.5% 17. Other18. LEL > 10% 20.21. Carbon Monoxide (CO) ppm Other24. Hydrogen Sulphide (H2S) ppm Other27. PPE Respirators 29.Rescue Equipment30. Other Other Other33. Names of entrants, Attendants, and Entry Supervisors:34. Time work / shift completed: (35.) Problems / concerns36. Emergency contact:
23 Other OSHA Regulations Hazard Communication29 CFRMSDSTrainingLabelingWritten ProgramControl of Hazardous Energy Sources29 CFR &“Lock Out/Tag Out”De-Energize ALL Sources of EnergyWritten Program
25 Permit Space Entry Program Learning ObjectivesDescribe the Guidelines for a Permit-Required Confined Space ProgramIdentify Conditions Which Allow the Use of Alternate Procedures
26 General Requirements A Written Permit Space Program Authorized PersonnelConfined Space Evaluation ProceduresAcceptable Entry Conditions and Procedures
27 The Entry Permit Shall Identify: PRCS ProgramThe Entry Permit Shall Identify:1) The Permit Space to be Entered.2) The Purpose of the Entry.3) The Date and Duration.4) The Authorized Entrants.5) The Attendants.6) The Entry Supervisor.7) The Hazards of the Space to be Entered.8) Measures to Isolate and Eliminate the Hazards Before Entry.9) The Acceptable Entry Conditions.10) The results of Initial and Periodic Tests with Initials ofTesters.
28 The Entry Permit Shall Identify: PRCS ProgramThe Entry Permit Shall Identify:11) The Rescue and Emergency Services That Can BeSummoned.12) The Communication Procedures Used By Entrants andAttendants.13) Equipment such as Testing, Communication andEmergency Equipment.14) Any Other Information Necessary, In Order To EnsureEmployee Safety.15) Any Additional Permits Such As a Hot Work Permit.
29 Authorized Entrant Duties Knows Hazards, Symptoms, and ConsequencesProper Use of EquipmentCommunicate With AttendantExit Promptly From PRCS When Necessary
30 Attendant Duties Knows Hazards, Symptoms, and Consequences Awareness of Behavioral Effects of ExposureContinuously Identifies Number and Identity of EntrantsRemains Outside of PRCSCommunicates With Entrants
31 Attendant Duties Monitors Entrant & Surrounding Activity Summons Rescue If NeededKeeps Unauthorized Persons Away From PRCSPerforms Non-Entry RescuesPerforms Only Attendant Duties
32 Entry Supervisor Duties Knows Hazards, Symptoms, and ConsequencesVerifies Performance of Permit Testing, Procedures and EquipmentTerminates PRCS Entry and Permit
33 Entry Supervisor Duties Verifies Availability and Communication With Rescue ServicesRemoves Unauthorized PersonnelDetermines Compliance With the Entry Permit
34 Rescue and Emergency Services Using Employer’s Personnel...Trained in PPE and Rescue EquipmentTrained in Rescue and Authorized Entrant DutiesPractice Rescues Once Every 12 MonthsSimulated With Mannequins or PeopleIn Actual PRCSTrained in CPR and Basic First AidAt Least 1 Member of Rescue Service Holding Current Certification
35 Rescue and Emergency Services Outside Rescue Service...Must Be Informed of Hazards Prior to ArrivalMust Have Access to All Spaces to Assess and Allow for Practice of Rescues
36 Rescue and Emergency Services Non-Entry Rescue...“Retrieval Systems or Methods Shall Be Used Whenever an Authorized Entrant Enters a PRCS”Unless Equipment Increases Risk or Would Not Assist RescueChest or Full Body Harness, Center of Back Near Shoulder or Above Head; Wristlets ONLY if Harness is Infeasible or Greater HazardAttached to Mechanical Device or Fixed Point Outside SpaceMSDS Must Be at Worksite and Furnished to Medical Facility Treating Exposed Entrants
37 Testing and Monitoring Appendix B Evaluation TestingAny HazardsPrior to EntryTechnically Qualified ProfessionalOSHA Consultation ServiceCIHRegistered Safety EngineerCSPVerification Testing
38 Testing and Monitoring Appendix B Duration of TestingTesting Stratified AtmospheresAtmospheric Envelope of 4 ft. in Direction of Travel and to All SidesRate of Progress of Entrant Slowed to Accommodate Instrument Sampling Speed and Response Time
39 Hot Work PermitsDefined As: Written Authorization to Perform Operations Capable of Providing a Source of Ignition (Such As Welding, Cutting, or Brazing)Required for: Hot Work in Grain Handling Facilities and Any Other Combustible/ Explosive Areas
40 Hot Work Permits General Provisions Remove Fire Hazards & CombustiblesGuard the WorkGuard Openings to Other AreasMaintain Fire Extinguishers
41 Hot Work Permits General Provisions Maintain Fire WatchWritten Permit AuthorizationProtect Floors & WallsProtect Drains, Dusts, and Pipes
42 Alternate ProceduresCan be used if...ONLY Hazard is an Actual or Potential Hazardous AtmosphereAndCan Demonstrate That Continuous Forced Air is Sufficient to Maintain the Space as SafeData is Developed to Support the AboveA Permit Program is Followed During Data Collection
43 Alternate Procedures (continued) Hazard from Removing Entrance Cover is EliminatedEntrance is Made Safe to Prevent Accidental FallsAtmospheric Testing forOxygenFlammabilityToxic Contaminants
44 Alternate Procedures (continued) No Hazardous Atmospheres Develop While Employee is In SpaceContinuous Forced Air Ventilation is UsedNo Entry Until SafeRemains Until Everyone Has Left SpaceAir is From a Clean, Safe SourcePeriodic Testing
45 Alternate Procedures (continued) If A Hazard DevelopsEvacuation of SpaceEvaluation as to the SourceProtection of Employees Prior to Re-entryDocumentationDate, Location, Signature of Person CertifyingCertification Made Prior to Entry and Available to each Employee
46 Alternate Procedures (continued) At Issue -“Elimination” of HazardsIf the Stated Conditions Are Met, the Employer Does Not Have to ImplementOSHA Compliance Letter (10/12/95) Interprets the Elimination Provision: “… If the Non-Atmospheric Hazards Were Permanently Eliminated, the Alternate Procedures Could Subsequently Be Applied…”PRCS ProgramPermit SystemEntry PermitPersonnel DutiesRescueEmergency Services
47 Hazards are usually dictated by... The material stored in the confined space.The activity carried out in the confined space. (a particular chemical reaction)The external environment. (a tank located near rising waters)
48 OSHA Estimates224,000 establishments have permit required confined space.2.1 million workers enter these spaces annually.60% of the deaths that occur in confined spaces are the rescuers who go in after the victim.
49 Confined Space Hazards Chemical HazardsPhysical HazardsBiological HazardsErgonomic Hazards
50 EngulfmentThe surrounding or covering of a person by a liquid or flowable solid. Death may result by suffocation, strangulation, constriction, or crushing.ConcreteAsphalt
51 Primary Constituents of Normal Air (Permanent Gases) ChemicalFormulaMolecularWeightPercentby VolumeConstituentNitrogenN22878.1OxygenO23220.9ArgonAr400.9Water vapor content varies, but is usually the third largest constituent by volume in air.
52 Definitions of O2 Deficient Atmosphere 29 CFR (PRCS) <19.5%42 CFR Part 84 (NIOSH Resp. Approval) <19.5%29 CFR (g) (Resp. Std.) %129 CFR (Ventilation. Std.) <19.5%29 CFR (b) (Shipyards) <19.5%ANSI Z (Confined Spaces) <19.5%ANSI Z (Respirator Practices) %2ACGIH (TLV booklet) %1 Letter of interpretation2 Oxygen partial pressure <122 mmHg. Confined space with <20.9 % O2 is IDLH, unless source of O2 reduction is understood and controlled.Source Oxygen Content
53 Oxygen-Deficient Atmospheres O2 Content15-19%Effects and Symptoms (at patm)Decreased ability to work strenuously. May impair coordination and induce early symptoms in persons with coronory, pulmonary, or circulatory problems.Respiration increases in exertion, pulse up, impaired coordination, perception, and judgment.Respiration further increases in rate and depth, poor judgment, lips blue.Mental failure, fainting, unconsciousness, ashen face, blueness of lips, nausea, and vomiting.8 min., 100% fatal; 6 min., 50% fatal; 4-5 min., recovery with treatment.Coma in 40 sec., convulsions, respiration ceases, death.12-14%10-12%8-10%6-8%4-6%NOTE: Exposure to atmospheres containing 12% or less oxygen will bring about unconsciousness without warning and so quickly that individuals cannot help or protect themselves.
54 How an Oxygen-Deficient Atmosphere Can Occur in a Confined Space 1. Consumption Adsorptiona) a)b)c)2. Displacementa)
55 Argon (Ar) Nitrogen (N2) Colorless, odorless inert gas Slightly lighter than airArgon (Ar)Colorless, odorless inert gasHeavier than air
56 Argon (Ar)Colorless, odorless inert gasHeavier than air
57 Methane (CH4) Natural, marsh, swamp gas Colorless, odorless flammable gasLighter than airToxic?LEL = 5%; UEL = 15%
58 Carbon Dioxide (CO2) Colorless, odorless noncombustible gas Heavier than airCommon in solid and compressed liquid formsCarbonationInertingOrganic decay (grain elevators, sewers, storage bins, wells)Fermentation (digestors, molasses pits, beer and wine vats)
59 CO2 (cont’d) PEL = 5,000 ppm - TWA (Table Z-1) TLV/REL = 5,000 ppm - TWA; 30,000 ppm - STELIDLH = 50,000 ppmLEL = none
60 Carbon Monoxide (CO) Colorless, odorless gas Slightly lighter than air Chemical asphyxiantPrimary source: incomplete combustion of organic materialGasoline-fueled combustion engines
61 CO (cont’d) PEL = 50 ppm - TWA TLV = 25 ppm - TWA BEI: <3.5% COHb; 20 ppm (end-exhaled air)REL = 200 ppm - STEL; 35 ppm - TWAIDLH = 1500 ppmLEL = 12.5%; UEL = 74.2%
62 Concentration of CO Necessary to Produce Symptoms Percent ppm EffectsPossibly headache, mild frontal in 2-3 hrs.Headache, frontal, and nausea after 1-2 hrs.; occipital after 2-1/2 to 3-1/2 hrs.Headache, dizziness and nausea in 3/4 hour, collapse and possible unconsciousness in 2 hrs.,600 Headache, dizziness and nausea in 20 min.; collapse, unconsciousness, possibly death in 2 hr.,200 Headache and dizziness in 5 to 10 min., unconsciousness and danger of death in 30 min.,400 Headache and dizziness in 1 to2 min., unconsciousness and danger of death in 10 to 15 min.,800 Immediate effect; unconsciousness and danger of death in 1 to 3 min.(Source: Hamilton & Hardy)
63 Symptoms of CO Exposure Percent* Symptoms0-10 Shortness of breath on exertionTightness across forehead, slight headacheThrobbing headacheSevere headache, nausea, vomiting, collapse on exertionAll symptoms increased, pulse rate and breathing increasedComa, interrupted breathing (Cheyne-Stokes), death* Percent saturation of Hemoglobin with CO [Blood Levels]
67 Effects of H2S Concentration ppm* Local Systemic2050 Irritant of conjunctival andcorneal epitheliumEye and respiratory tractirritation in 1 hr.Slight systemic symptoms after several hrs.150 Olfactory nerve paralysis Fatal in 8-48 hrs.200 Pulmonary irritation and pulmonary Nervous system depressionedema after prolonged exposure* Concentration by Volume
68 Effects of H2S Concentration (cont’d) ppm* Local SystemicFatal in 4-8 hrs.Fatal in 1-4 hrs.Excitement, headache, dizziness and unconsciousness, death in min.Rapid collapse, death in 2-15 min.700-2, Cessation of respiration, rapidly fatal* Concentration by Volume
69 Other Toxics May arise from the: 1. Product(s) stored 2. Manufacturing processes3. Work being performed4. Adjacent areas
70 DefinitionsVapor Pressure- Pressure exerted by a vapor. If a vapor is kept in confinement over its liquid so that the vapor can accumulate above the liquid, the vapor pressure approaches a fixed limit called the maximum vapor pressure. (How much the liquid wants to become a gas)Flash Point- The minimum temperature at which a liquid gives off vapor within a test vessel in sufficient concentration to form an ignitable mixture with air near the surface of the liquid.
72 Flammable (Explosive) Limits When vapors of a flammable or combustible liquid are mixed with air in the proper proportions in the presence of a source of ignition, rapid combustion or an explosion can occur. The proper proportion is called the flammable range and is also often referred to as the explosive range. The flammable range includes all concentrations of flammable vapor or gas in air, in which a flash will occur or a flame will travel if the mixture is ignited. There is a minimum concentration of vapor or gas in air below which propagation of flame does not occur on contact with a source of ignition. There is also a maximum proportion of vapor in air above which propagation of flame does not occur. These boundary-line mixtures of vapor with air are known as the lower and upper flammable or explosive limits (LFL or UFL) respectively, and they are usually expressed in terms of percentage by volume of vapor in air.
73 Atmospheric PressureAtmospheric pressure is 760 mmHg a substance with a vapor pressure of 760 mmHg is a gas at room temperature.Water vapor pressure= 25 mmHgFuel oil vapor pressure= 2 mmHgVinyl chloride vapor pressure= (760 mmHg)(3.4)“1300 rule”1300*VP= concentration just above the surface of the liquid
74 MSDS Exercise What color is this substance? What type of odor does it have?What PEL or TLV is set for this substance?What are some of the synonyms for this substance?What products are incompatible with this product?What type of PPE should be worn while handling this product?What are some of the symptoms of overexposure?If a co-worker was overexposed to this product what information should be give to medical personnel?Is this substance designated as a hazardous waste by the EPA?Who might you call for more information about this product?
75 Permit-Required Confined Spaces Air MonitoringPermit-Required Confined Spaces
76 Objectives Describe Why the Work Environment Needs to Be Monitored Understand the Value of Personal, Area, and Perimeter MonitoringIdentify Several Types of Monitoring Equipment
77 Why Do Monitoring? To Detect if Potential Hazardous Conditions Exist To Measure Concentrations of Hazardous Substances
78 Detection of HazardsTo Determine Whether Hazardous Materials Are Present Under Normal ConditionsWhether the Environment is IDLHMeasure Releases During Work to Ensure Proper PPE and Work PracticesEnsure That No Hazardous Materials Remain After a Release
79 Hazards In The Air Oxygen Deficiency/Enrichment Explosive Atmospheres Toxic ChemicalsRadioactivityBiological Hazards
80 Oxygen Oxygen Enriched Oxygen Deficient 23.5% 19.5% Minimum for Safe Entry16.0%Impaired Judgment& Breathing14.0%Faulty JudgmentRapid Fatigue6.0%Difficulty in BreathingDeath in Minutes
81 Explosive LimitsToo RichUELCombustibleLELToo Lean10% of LEL
82 Personal Air Monitoring PROCONLab Analysis 1 to 14 DaysNo Peak or Ceiling MeasuresNeed to Know What Exposures are PossiblePreparation and Calibration Needed Prior and FollowingAccurate Measure of Actual ExposureCompares to OSHA PEL, STELDocuments ExposureAllows Appropriate PPE Selection
83 Personal Monitoring Equipment Battery Operated Sampling PumpsFilters - Fumes/Particles/MistsCharcoal Tubes - Gases/VaporsSilica Gel Tubes - Gases/VaporsPassive Badge DosimetersGases and Vapors
84 Real-Time Measurements PROCONImmediate MeasuresMeasures Variety of ExposuresMeasures IDLH SituationsDetects Peak Toxic and Flammable LevelsDetermines Ability to Enter PRCSMay Not Detect “Low” LevelsNot SpecificMay False AlarmInterferences and Cross SensitivityMay Require Factory Calibration
85 Direct Reading Instruments Oxygen MeterExplosive Gas Meter/Combustible Gas IndicatorDetector TubesPersonal Alarm MonitorsMulti-Gas Analyzer/Meters
87 Review Where Are Measurements Taken? What Types of Measurements Can Be Made?How Are These Measurements Used?What Are Some of the Limitations of Air Sampling?Make sure to talk about varying levels of oxygen concentrations due to stratification, possibly caused by different vapor densities of released gases in a silo, manure pit, or grain bin. It is necessary to lower sampling device to measure at all depths/heights. See Appendix B...12
88 Instrumentation O2 Meters Flammable Gases and Vapors Use O2 MetersFlammable Gases and VaporsUse Combustible Gas IndicatorToxic Air ContaminantsUse Colorimeteric Detector Tubes
89 Combustible Gas Indicators Used to sample vapor concentrations near and in permit spacesReads LELA reading above 10% should be considered a potentially explosive atmosphere
90 Combustible Gas Indicators Precautions The equipment may not respond the same to all vaporsO2 MUST BE MEASURED FIRST!
91 Oxygen MetersUsed to sample oxygen concentrations in and near confined spaces.Reads between 0-25% or 0-100%At greater than 23.5% O2, the explosion hazard increases.At less than 19.5% the space cannot be entered without a SCBA or SAR with escape pack.
92 Oxygen Meter Precautions Very sensitive to temperature and pressure changes.At high concentrations of carbon monoxide, the meter may give improper readings.Must be calibrated before every use!
93 Colorimeteric Detector Tubes Used to sample gas or vapor concentration in any work space.Reads percent of the concentration in PPM.Concentration indicated by color change or length of color stain.
94 Detector Tube Precautions They are not very accurate-- within 25% of the real value at best.The tubes are very sensitive to temperature and humidity.Different tubes must be used for different chemicals.They are breakable.
95 Tips To Help In Monitoring Check the accuracy of the instruments you are going to use.Have they been recently calibrated?Always test in this order: Oxygen, Flammability/Combustibility, and Toxic Gases.Test the air from the top to bottom including all corners and spaces!Test the atmosphere frequently!
97 Comfort - General/Dilution Ventilation Temperature and humidity regulations ASHRAEWinter: oFSummer: oFRH: %
98 Comfort - General/Dilution Ventilation (cont’d) Odor removal - outside air movement ASHRAEPublic bathrooms: 50 CFM/wc or 2 CFM/ft2Office: 15 CFM/personSmoking lounges: CFM/person
99 Safety - General/Dilution Ventilation Fire and explosion control(1) Volume of air required to dilute the vapor from 1 gallon of solvent to 25% LEL. [ (c)(6)(ii)]4(100-LEL)VVDilution volume =LELVV = cubic feet of vapor per gallon of solvent (vapor volume)
100 Safety - General/Dilution Ventilation (cont’d) Example: acetone4( )44.0Dilution volume =2.5= 6,864 ft3 air / gal acetone (70oF)
101 Safety - General/Dilution Ventilation (cont’d) (2) Volume of air required to dilute the vapor from 1 gallon of solvent to 10% LEL. [ (b)]10(100 - LEL)VVDilution volume =LEL
102 Safety - General/Dilution Ventilation (cont’d) Example: acetone10( )44.0Dilution volume =2.5= 17,160 ft3 air / gal acetone (70oF)
103 Ventilation Volume Calculation Ventilation volume = Dilution volume x Gallons of solvent evaporated per minuteft3 airgal solventCFM =xgal solventmin
104 Ventilation Volume Calculation (cont’d) Example: Acetone-thinned paint applied at rate of one gallon per minute. Paint is 40% solvent.Ventilation volume (for 25% LEL)6,864 ft3 air gal paint gal solventxx= 2,746 CFMgal solvent min gal paintVentilation volume (for 10% LEL)17,160 ft3 air gal paint gal solventxx= 6,864 CFMgal solvent min gal paint
105 Dilution Ventilation for Fire and Explosion Reduce the concentration of vapors within an enclosure to below the LEL.This concept is never applied in cases where workers are exposed to the vapor. Dilution rates for health hazard control are always applied in these instances, since the PEL is a much lower concentration than the LEL.
106 Safety - Dilution Ventilation 403(SG)(100)(C)(w)Q =(MW)(LEL)(B)where,Q = air flow rate (CFM) required to dilute vapor concentration to safe condition403 = conversion factorSG = specific gravity of liquid (water = 1)
107 Safety - Dilution Ventilation (cont’d) 100 = constant to convert LEL to decimal fractionC = dimensionless safety factor which depends on % LEL necessary for safe conditions (10% LEL: C = 10, 25% LEL: C = 4)w = pints of liquid evaporated in one minuteMW = molecular weight of vaporLEL = lower explosive limit (%)B = constant reflecting fact that LEL decreases at elevated temperatures (£ 250oF: B = 1, > 250oF: B = 0.7)
108 Flammable Liquid Storage Rooms Ventilation must provide for a complete change of air within the room at least six times per hour (6 A.C. / hr).Exchanging all the air in the room is equivalent to 1 A.C. [i.e., Room volume (L x W x H) = 1 A.C.]6 A.C. / hr = (6 x Room volume) / hrCFM = [6 x Room volume (ft3)] x 1 hr / 60 minCFM = Room volume (ft3) / 10
109 Health - Dilution Ventilation 403(SG)(106)(w)(K)Q =(MW)(PEL)where,Q = air flow rate (CFM) required to dilute vapor concentration to the PEL.K = dimensionless safety factor (varies from 3-10) to maintain concentration well below PEL. Higher value for high toxicity, high evolution rate, poor ventilation, and large number of exposed workers.
110 Considerations for PRCS Ventilation Space configurationVentilation mode (exhaust/supply)Ventilation flow rateAvailability of make-up airObstacles for ductingAvailability of power sourcesLocation of employee within spaceCharacteristics of contaminant
111 Achievement of Accceptable Atmospheres Dilution - use general/forced air ventilation to dilute the contaminantExhaust - use local exhaust ventilation to remove the contaminantDilution/Exhaust - use a combination of both methods to remove the contaminant
112 Dilution Ventilation Introduces fresh air to space Best when toxicity levels and concentrations are lowBest when contaminants well distributedRequires larger air volume when contaminants generated at a point
113 Local (Source) Ventilation Exhausts from a localized areaRemoves high concentrations of contaminants from spaceRequires smaller volume of air
115 InertingDisplacement of the atmosphere by a non-reactive gas (such as nitrogen) to such an extent that the resulting atmosphere is noncumbustible.
116 PurgingThe method by which gases, vapors, or other airborne impurities are displaced from a confined space.Purpose is to do a complete air exchange in a confined space prior to entry. Normally, a purge is considered complete when atmospheric tests indicate the air is of suitable quality to sustain life.InertingDisplacement of the atmosphere by a non-reactive gas (such as nitrogen) to such an extent that the resulting atmosphere is noncumbustible.
117 Ventilation At opening of blower 100% capacity Blower plus 25’ of hose 78% capacity25’ of hose plus one 90 degree bend 67% capacity25’ of hose plus two 90 degree bend 56% capacity
118 Electricity Electricity Doesn’t Spring Into Action Until Current Flows Current Doesn’t Flow Until there is a Loop to and from the TransformerCurrent Always Returns to the Transformer that created it
119 Electricity Voltage Water Pressure Ohms Resistance / Size of Water PipeCurrent Flow Rate of Water
120 Electrical Shock Contact with a normally energized conductor (wire). Contact with an energized conductor on which the insulation has lost it’s protective valueEquipment failure, causing an open or short circuitStatic Electricity DischargeLightning Strike
121 Cords & Corded Equipment Do not remove ground plugFlexible cords must Not be: Used instead of fixed wiring Run through holes in ceilings, walls, or floors Run through doorways, windows, or openings Concealed in walls, ceilings, or floorsFlexible cords may be used for: Pendants Fixture wiring Portable lamps or appliances Cranes and hoists Frequently Moved equipment
122 Control of Hazardous Energy Sources Lockout/Tagout29 CFRControl of Hazardous Energy Sources(Lockout/Tagout)
123 Scope (a)(1)(i)Covers servicing and maintenance of machines when unexpected startup or release of stored energy could cause injury.
124 Application (a)(2)(i)Standard applies to control of energy during servicing and/or maintenance.Note: Servicing / maintenance during normal production operations is covered if:an employee is required to remove or bypass a guard, oran employee must place his / her body into danger zone
125 Does not cover: 1910.147 (a)(1)(ii) Construction, agriculture, maritimeInstallations under control of electric utilitiesExposure to electrical hazards from work on, near, or with conductors or equipment in electrical utilization installations (see Subpart S)Oil and gas drilling, and servicing
126 Also Excluded 1910.147 (a)(2)(ii) & (iii) Normal production operations (see Subpart O)Work on cord and plug connected equipmentHot tap operations, under special conditions
127 Definitions 1910. 147 (b) & (c)(7)(i)(C). While not defined in 1910 Definitions (b) & (c)(7)(i)(C) *While not defined in (b), “other employees” are discussed in (c)(7)(i)(C).Authorized Employee: Person who locks or tags machines / equipment to perform servicing.Affected Employee: One who is required to use machines / equipment on which servicing is performed under lockout / tagout or who must work in such an area.Other Employees: * All employees whose work operations are or may be in an area where energy control procedures may be utilized.
128 Definitions (continued) 1910.147 (b) “Capable of being locked out”Designed with hasp or attachment to which lock can be affixed; or,Has locking mechanism built in; or,Lockout can be achieved without need to dismantle, rebuild, replace or permanently alter.
129 Definitions (continued) 1910.147 (b) Normal Production Operations: Utilization of a machine or equipment to perform its intended function.Servicing and/or Maintenance: Includes lubrication, cleaning or unjamming, making adjustments and tool changes, where employees may be exposed to UNEXPECTED energization, startup or release of hazardous energy.
130 Energy Control Program 1910.147 (c)(1) The employer shall establish a program consisting of an energy control procedure and employee training... in accordance with paragraph (c)(4) of this section.
131 Lockout vs. TagoutLockout system is preferred method and shall be used when equipment can be locked out -- unless employer can show that tagout system provides full employee protection.
132 Full Employee Protection 1910.147 (c)(3)(i) When tagout is used on equipment which is capable of being locked out:Tags shall be attached where lockout devices would be; and,Employer must demonstrate that tagout will provide safety equivalent to lockout.
133 Energy Control Procedure 1910.147 (c)(4)(i) Procedures shall be developed, documented and utilized for the control of potentially hazardous energy when employees are engaged in servicing and maintenance.
134 Energy Control Procedures must be written, unless all of the following exist: (c)(4)(i) exceptionEquipment has no potential for stored / residual energy.Equipment has a single energy source.Isolation and lockout of one energy source completely deactivates equipment.Equipment is isolated from energy source & locked out.Lockout device is under exclusive control of authorized employee performing maintenance.No other hazards are created.Employer has had no related accidents.
135 Procedures must contain: 1910.147 (c)(4)(ii) ScopePurposeAuthorizationRulesTechniques to be utilizedMeans to enforce compliance
136 Materials / Hardware 1910.147 (c)(5) Provided by employerSingularly identifiedOnly devices usedNot used for other purposesDurableStandardizedSubstantial
137 Periodic Inspection 1910.147 (c)(6)(i) At least annuallyPerformed by authorized employee (other than the one(s) using procedure being inspected).Designed to correct deficiencies.Lockout: Must review each authorized employee’s responsibilities.Tagout: Must review each authorized and affected employee’s responsibilities and additional training requirements of (c)(7)(ii).Employer certification required.
138 Training 1910.147 (c)(7)(i) Authorized Employee Affected Employee Recognition of hazardous energy sourcesType & magnitude of energy in workplaceMethods for energy isolation / controlAffected EmployeePurpose / use of energy control procedureOther EmployeeProcedureProhibition on restarting machines or equipment
139 Additional Training - Tagout System 1910.147 (c)(7)(ii) Employees shall be trained in the limitations of tags, as follows:Warning devices onlyMust not be removed / bypassed / ignoredMust be legibleMust withstand environmental conditionsMay (will) evoke false sense of securityMust be securely attached
140 Employee Retraining 1910.147 (c)(7)(iii) Provided when:Change in job assignmentsChange in machines, equipment or processes that present new hazardsChange in energy control proceduresPeriodic inspection reveals, or employer has reason to believe, there are deviations in employee knowledge of procedures
141 Specific Procedures 1910.147 (d)(1) - (6) Lockout / Tagout procedures shall cover the following elements in the following sequence:Preparation for shutdownShutdownIsolationLockout / tagout device applicationRelease of stored energyVerification of isolation
142 Release from Lockout / Tagout 1910.147 (e)(1) - (3) Prior to restoring energy, the following procedures are required:Inspect machine and equipmentSafe positioning and notification of employeesRemoval of lockout / tagout device
143 Testing of Machines 1910.147 (f)(1) When lockout / tagout devices must temporarily be removed for testing / positioning:Clear machine of tools / equipmentRemove employeesRemove lockout / tagout deviceEnergize and testDe-energize and reapply energy control measures
144 Outside Personnel (Contractors) 1910.147(f)(2) On-site employer and outside employer shall inform each other of their respective procedures.On-site employer shall ensure that his / her employees understand and comply with contractor’s procedures.
145 Group Lockout / Tagout 1910.147 (f)(3) Additional RequirementsPrimary responsibility is vested in an authorized employee for a set number of employees.Authorized employee must ascertain exposure status of group members.If more than one crew is involved, coordinator needed.Each authorized employee shall use a personal lockout / tagout device and remove it when finished.
146 Shift / Personnel Changes 1910.147 (f)(4) Specific procedures needed to ensure continuity of lockout / tagout protection.
147 Lockout/Tagout Purpose - 1910.147(a)(3) This section requires employers to establish a program andutilize procedures for affixing appropriate lockout devices ortagout devices to energy isolating devices, and to otherwisedisable machines or equipment to prevent unexpectedenergization, start-up or release of stored energy in order toprevent injury to employees.
148 Lockout/Tagout Definitions - 1910.147(b) Affected employee: An employee whose job requires him/her to operate or use a machine or equipment on which servicing or maintenance is being performed under lockout or tagout, or whose job requires him/her to work in an area in which such servicing or maintenance is being performed.Authorized employee: A person who locks out or tags out machines or equipment in order to perform servicing or maintenance on that machine or equipment. An affected employee becomes an authorized employee when that employee’s duties include performing servicing or maintenance covered under this section.Energy isolating device: A mechanical device that physically prevents the transmission or release of energy.
149 Lockout/Tagout Employer Responsibilities EducationDocumentation: a written statement of company’s Energy Control Plan.Employee training: to help employees in the use of the Energy Control Plan.EnforcementInspection: to make sure energy control procedures are being carried out.Self-audit: a periodic review of the procedures and the program.
150 Lockout/Tagout General - 1910.147(c) The employer shall establish a program consisting of energycontrol procedures, employee training and periodic inspectionsto ensure that before any employee performs any servicing ormaintenance on a machine or equipment where the unexpectedenergizing, start up or release of stored energy could occur andcause injury, the machine or equipment shall be isolated fromthe energy source, and rendered inoperative.
151 Lockout/Tagout Applying Energy Controls Energy isolation and lockout/tagout are to be applied only by trained employees authorized to perform service or maintenance.Before lockout/tagout is applied, all employees who work in the affected area must be notified.The OSHA regulation requires that control of hazardous energy be done according to a six-step procedure.
152 Lockout/Tagout Preparation for Shutdown - 1910.147(d)(1) Before you turn off any equipment in orderto lock or tag it out, you must know:The types and amounts of energy that power itThe hazards of that energyHow the energy can be controlled
153 Lockout/Tagout Equipment Shutdown - 1910.147(d)(2) Shut the system down by using its operating controls.Follow whatever procedure is right for the equipment, so that you don’t endanger anyone during shutdown.An orderly shutdown must be utilized to avoid any additional or increased hazard(s) to employees as a result of the equipment stoppage.
154 Lockout/Tagout Equipment Isolation - 1910.147(d)(3) Operate all energy-isolating devices so that the equipment is isolated from its energy sources.Be sure to isolate all energy sources-secondary power supplies as well as the main one.Never pull an electrical switch while it is under load.Never remove a fuse instead of disconnecting.
155 Lockout/Tagout Application of LOTO Devices - 1910.147(d)(4) All energy-isolating devices are to be locked, tagged or both according to company’s Energy Control Plan.Only the standardized devices supplied by your employer are to be used for lockout/tagout, and they are not to be used for anything else.Use a lockout device if you lock cannot be placed directly on the energy control.When lockout is used, every employee in the work crew must attack his/her personal lock.More than one employee can lock out a single energy-isolating device by using a multiple-lock hasp.For big jobs, a lockout box can be used to maintain control over a large number of keys.If tags are used instead of locks, attack them at the same point as you would a lock, or as closed to it as possible.Fill tags out completely and correctly.
156 Lockout/Tagout Control of Stored Energy - 1910.147(d)(5) Inspect the system to make sure all parts have stopped moving.Install ground wires.Relieve trapped pressure.Release the tension on springs, or block the movement of spring-driven parts.Block or brace parts that could fall because of gravity.Block parts in hydraulic and pneumatic systems that could move from loss of pressure.
157 Lockout/Tagout Control of Stored Energy (con’t.) - 1910.147(d)(5) Bleed the lines and leave vent valves open.Drain process piping systems and close valves to prevent the flow of hazardous materials.If a line must be blocked where there is no valve, use a blank flange.Purge reactor tanks and process lines.Dissipate extreme cold or heat, or wear protective clothing.If stored energy can reaccumulate, monitor it to make sure it stays below hazardous levels.
158 Lockout/Tagout Equipment-Isolation Verification - 1910.147(d)(6) Take any of the following steps that fit yourcompany’s equipment and energy control program.Make sure all danger areas are clear of personnel.Verify that the main disconnect switch or circuit breaker can’t be moved to the on position.Use a voltmeter or other equipment to check the switch.Press all start buttons and other activating controls on the equipment itself.Shut off all machine controls when the testing is finished.
159 Lockout/Tagout Removing Energy Controls Make sure the equipment is safe to operate.Remove all tools from the work area.Be sure the system is fully assembled.Safeguard all employees.Conduct a head count to make sure everyone is clear of the equipment.Notify everyone who works in the area that lockout/tagout is being removed.Remove the lockout/tagout devices. Except in emergencies, each device must be removed by the person who put it on.
160 Lockout/Tagout Removing Energy Controls (con’t.) In some workplaces, the last person to remove his/her lock may have extra duties.He/she may have to remove the hasp and lockout device.Tags should be removed, signed, and turned in.In some companies, the supervisor always removes his lock last.Follow a checklist of required steps to re-energize the system.
161 Limitations of Tags 1910.147(c)(7)(ii) Tags are essentially warning devices affixed to energy isolating devices, and do not provide the physical restraint on those devices that is provided by a lock.When a tag is attached to an energy isolation means, it is not to be removed without authorization of the authorized person responsible for it, and it is never to be bypassed, ignored, or otherwise defeated.Tags must be legible and understandable by all authorized employees, affected employees, and all other employees whose work operations are or may be in the area, in order to be effective.Tags and their means of attachment must be made of materials which will withstand the environmental conditions encountered in the workplace.Tags may evoke a false sense of security, and their meaning needs to be understood as part of the overall energy control program.Tags must be securely attached to energy isolating devices so that they cannot be inadvertently or accidentally detached during use.
162 Respiratory Protection The basic function of a respirator is to reduce the risk of respiratory injury due to breathing airborne contaminants. A respirator provides protection by removing the contaminants from ambient air or by supplying the wearer with an alternate source of clean breathing air.All respiratory apparatus are composed of two main parts:the device which supplies or purifies air,the facepiece which covers the nose and mouth and seals out the contaminants.The first component defines what class of respirator the device is; the second determines the relative measure of protection afforded by that respirator.
163 Respirator Program Elements 1. Selection2. Medical evaluation3. Fit testing4. Use5. Maintenance and care6. Breathing air quality and use7. Training8. Program evaluation
164 Respiratory Protection Classifications of respirators:Air purifying respirators (APRs)Particulate- mechanical filterGas and vapor- chemical cartridgeRequires knowledge of ambient concentration and Maximum Use Limit (MUL) of the respiratorAPRs only clean the air, the ambient concentration of oxygen must be sufficient (19.5%) for the user
165 Air-Purifying Respirator (APR) An air-purifying respirator that uses a blower to force the ambient air through air-purifying elements to the inlet covering.
166 Respiratory Protection Classifications of respirators:Air supplying respirators (ASRs)Provide a substitute source of clean breathing air.The respirable air is supplied to the worker from either a stationary source through a long hose, or from a portable container.The first type are called supplied-air respirators.The second type are known as self-contained breathing apparatus.
167 Supplied Air Respirator (SAR) An atmosphere-supplying respirator for which the source of breathing air is not designed to be carried by the user. Also called airline respirator.
168 Self-Contained Breathing Apparatus (SCBA) An atmosphere-supplying respirator for which the breathing air source is designed to be carried by the user.