Post on 12-Jun-2015
description
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Confined Space
Entry
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Confined Space Overview
• Definitions
• Confined Space Hazards
• Equipment Requirements
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Learning Objectives
• Regulatory Requirements
• Definitions
• Confined Space Hazards
• Hazard Identification
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Learning Objectives
• Responsibilities
• Entry Permits
• Lock-Out / Tag Out
• Atmospheric Monitoring
• Training Requirements
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Learning Objectives
• Alternate Entry Procedures
• Reclassification
• Respiratory Protection
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Facts• About 2.1 million workers enter
permit confined spaces Annually
• The majority of fatalities in confined space emergencies occur to rescuers
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Confined space is defined as the interior of an enclosed area or
structure• (a) is enclosed or partially enclosed,• (b) is not designed or intended for continuous
human occupancy,• (c) has limited or restricted means for entry or
exit that may complicate the provision of first aid, evacuation, rescue or other emergency response service, and
• (d) is large enough and so configured that a worker could enter to perform assigned work;
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Engulfment
• Being buried by free flowing loose granular materials such as sawdust or earth
• Being drowned in liquids
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Isolation
• Separating piping from a confined space
• May include blanking, blinding and double block & bleed
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Examples of Confined Spaces Are:
• Vessels• Tanks (septic, etc.)• Pipes (sewer, drain,
utility, etc.)• Vaults• Pits
• Silo’s• Trenches• Tunnels• Storage Bins• Manholes• Bore holes
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Entry into Confined Spaces may be necessary to
periodically perform the following functions:
• Inspection
• Cleaning
• Repairing
• Construction
• Maintenance
• Removal
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Hazards presenting a potential for injury, illness or death
• Toxic gases above the PEL
• Oxygen deficiency• Oxygen enrichment• Potential for
engulfment
• Flammable gas above 10% of the LEL
• Potential for IDLH atmospheres
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Ignition Sources
• A fire or explosion can occur due to:– Static electricity– Metal friction– Unapproved lamps or electrical equipment– Cigarettes Therefore NO SMOKING– Sparks from grinding or welding
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Toxic Contaminants
• Above TLV should be considered a serious potential hazard
• IDLH conditions pose serious danger to workers
• Contaminants may already be inside the space and/or introduced by work operations
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Oxygen deficient atmosphere
• May occur as a result of
– The work being done (welding)
– Chemical reactions (rusting)
– Bacterial decomposition
• May also occur by displacement of another gas
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Low oxygen symptoms
• 16% - Rapid breathing, drowsiness
• 14% - Faulty judgement, rapid fatigue
• 12% - Unconscious
• 6% - Death
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In PotentialOxygen deficient atmospheres
• Users Must wear SCBA or combination airline with egress cylinder
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The hazards of each confined space shall be identified by:
• Review of the past and current uses of the confined space
• Physical characteristics, configuration and location of the space
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Existing or potential confined space hazards
• Oxygen deficiency
• Flammable or explosive atmosphere
• Toxic Atmosphere
• Mechanical devices
• Physical obstacles
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Hazards identified need to be evaluated by a qualified person
with respect to:
• Scope of the hazard exposure
• Likelihood of hazard occurrence
• Consequence of hazard occurrence
• Potential for changing conditions
• Strategies for eliminating or controlling
• Emergency response capabilities
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Pre-Planning - Blinding/Flushing
• Pipes/lines must be disconnected, blinded or blocked off
• Physical locks are placed on breakers, valves and chains
• Space shall be emptied, flushed or purged of flammable or hazardous substances to the extent feasible
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Entry - Air Quality
• Test air initially & periodically with calibrated and tested air monitor to determine whether dangerous and/or oxygen deficiency exists
• Eliminate ignition source introduction until the hazardous condition has been eliminated
• Obtain hot work permit for ignition producing activities
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Entry - Air monitoring
• Oxygen deficient or enriched atmospheres– Test for Oxygen first– Less than 19.5% are IDLH– Greater than 23.5 are Oxygen enriched
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Entry - Air monitoring
• Flammable or Explosive Atmospheres
– Greater than 10% LEL are deemed hazardous
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Entry - Air monitoring
• If other toxics are suspected, must test or provide adequate protection for worker if above the PEL for the substance
• CO & H2S are most common toxics in confined space entry
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Entry - Air monitoring
• Maintain a written record of the monitoring performed prior to and during confined space operations.
• Employees shall have access to the monitoring results
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Entry - Air monitoring
• If dangerous air contamination/Oxygen deficiency does not exist, entry into the space requires that:– Air monitoring shall be done with sufficient
frequency to ensure that a dangerous air contamination and/or oxygen deficiency does not occur during the operation
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Entry - Retrieval Systems
• Approved retrieval system shall be set up
• Provide, inspect and test safety, rescue and retrieval equipment
• The retrieval system shall be attached to the workers using an approved harness and line
• Wristlets may be used if it can be demonstrated that a harness is not feasible or creates a greater hazard
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Entry - Retrieval Systems
• Retrieval line must be attached to a properly rated mechanical devise or fixed point outside the permit space
• The mechanical device must be available to retrieve personnel from a vertical type permit space 5 or more feet deep
• Lines & ropes should be configured within the space as the Entrants’ route
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Entry Permit
• Shall authorize entry only by designated and trained workers, into a specific confined space and for a specific purpose. The following items are required on each entry permit
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Items for Entry Permit
• Known or suspected hazards
• Steps to isolate the space; lockout/tagout
• Measures to remove or control potential hazards– purging, inerting, ventilation
• Testing/monitoring equipment and procedures for their use
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Items for Entry Permit
• Emergency response team available
• Rescue equipment provided on-site
• The personal protective equipment to be used
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Items for Entry Permit
• Check list to assure & certify that all pre-entry requirements have been met
• Name of person authorizing or in charge of entry
• Name of attendant
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Entry
• Recommended positive ventilation before and during all confined space entries– Where no fixed ventilation system exists, use a
portable explosion proof mechanical blower– Place the blower intake line so that the make-up
air is not taken from a contaminated environment
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Evaluation - Reclassification
• The only actual or potential hazard is atmospheric contamination
• Continuous forced ventilation alone is sufficient to maintain entry conditions
• Collect monitoring and inspection data to support decision
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Reclassification Compliance
• Must have written entry procedures
• Non-atmospheric hazards remain eliminated
• Testing and inspection confirm all hazards have and remain eliminated throughout operations
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Reclassification Compliance
• Written documentation of hazard elimination
• Documentation available to employees
• If hazards develop:– employer must reevaluate confined space
operations to see if permit-required entry is required
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Pre-entry
• Barricade/guard rail entrance
• Test atmosphere with Calibrated instrument
• Provide continuous forced ventilation– Until hazards are eliminated– Until entrants have vacated space– Must be clean air supply
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Entry
• Perform periodic atmospheric testing to insure no hazardous atmosphere develops
• If hazardous atmosphere is detected:– Immediately evacuate– Investigate causes– Implement additional protective measures prior
to re-entry
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Confined Space Definition
• A space with concurrent existence – Existing ventilation is insufficient to remove
dangerous air contamination and/or oxygen deficiency which may exist or develop
– Ready access or egress for the removal of a suddenly disabled employee is difficult due to the location and/or size of the openings
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Dangerous Air Contamination
• Greater than 20% of the LEL
• Toxics greater than IDLH
• Oxygen less than 19.5%
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Operating Procedures
• Written program
• Employee Training– Potential hazards– Operating procedures– Rescue procedures (may be self rescue)
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Pre-entry
• Hazardous lines must be blocked/blinded
• Exceptions!– Sewers & storm drains where no dangerous air
contamination could occur– Gas Utility distribution systems
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Procedures
• Purge, flush & empty to extent feasible
• Test air - record data
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Air Quality
• Acceptable Air - no hazards– Test air frequently/continuously
• Dangerous Air Contamination– augment existing ventilation– retest atmosphere
• Controlled Air Quality– enter space
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Possible Dangerous Air
• Use appropriate, approved respiratory protection• Use belt or harness for possible rescue• One standby employee required
– suitable respiratory protection with independent air source
– entry for rescue only upon notice to another employee with sight
– communication is required if employee out of sight
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Possible Combustible Gases
• No ignition sources (welding/cutting)
• Approved intrinsically safe lighting
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Top opening entry
• Approved suspension harness
• Hoisting devise or other means of retrieval
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Respiratory Protection
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Program Requirements
• Written Plan on how it will be administered
• Complete assessment and knowledge of the respiratory hazards
• Procedures and equipment to control the hazards; engineering controls, work practices
• Guidelines for selection of PPE
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Program Requirements
• Employee Training Program Covering:– Hazard Recognition– Dangers associated with respiratory hazards– Proper care, use, maintenance and inspection of
respirators
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Respiratory Hazards Oxygen Deficiency
• Must use supplied air respirator with egress cylinder or
• Self contained breathing apparatus
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Particulate Contaminants
– Dust
– Mist
– Fume
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Gas & Vapor Contaminants
• Inert gases
• Acidic gases
• Alkaline gases
• Organic compounds
• Organometallic compounds
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Respirator Selection
• What is the Hazard
• What is the concentration level
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Respirator Protection Factors
• Depends on the applicable OSHA standard– Lead– Asbestos– General Industry– Other regulation– DOE/DOD– Your company policy
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Respirator Maximum Use Concentrations
• PEL of the contaminant times the respirator protection factor is the Maximum Use Concentration, but
• Must be less than the IDLH level
• Must have adequate warning properties
• Must be able to be filtered/absorbed