Confined Space Entry

Objectives This is intended an overview of the confined space hazards and control Students should: Understand the extent of the problem Know applicable definitions Recognize the hazards of confined spaces Be familiar with methods to control these hazards Know basic OSHA requirements for confined space entry

Confined Space: Definition A Confined Space means a space that: Is large enough and so configured that an employee can bodily enter and perform assigned work ; and Has a limited or restricted means for entry or exit (For example: tanks, vessels, silos, pits, vaults,hoppers);and, Is not designed for continuous employee occupancy.

Permit Required Confined Space: Definition A Permit Required Confined Space means a confined space that has one or more of the following characteristics: Contains or has a potential to contain a hazardous atmosphere, Contains a material that has the potential for engulfing an entrant,

Permit Required Confined Space: Definition (cont’d) A Permit Required Confined Space means a confined space that has one or more of the following characteristics: Has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section. Contains any other serious safety or health hazard.

Confined Space Risk Confined spaces are deadly. OSHA data (annual) OSHA  63 fatalities  5000 serious injuries  Up to 60% of victims are would-be rescuers NIOSH documents: Preventing Occupational Fatalities in Confined Spaces Preventing Entrapment and Suffocation Caused by the Unstable Surfaces of Stored Grain and Other Materials (1987) Preventing Entrapment and Suffocation Caused by the Unstable Surfaces of Stored Grain and Other Materials (1987) Preventing Deaths of Farm Workers in Manure Pits Preventing Occupational Fatalities in Confined Spaces

Confined Space Risk Utah has many recent fatalities: Two welders died inside a pipe from argon asphyxiation, 1997 An employee died after being buried with salt while cleaning a bin, 1995 Two maintenance workers (one was a "rescuer") died from nitrogen asphyxiation while working in an oil-refinery tank, 1995 Two relatives (uncle and nephew) died inside an asphalt truck tank, 2000 A central Utah dairy worker was asphyxiated when he fell into a manure pit, 1998 A truck driver died when he went into a storage tank

Causes of Death (NIOSH) Atmospheric hazards - 56% of fatalities

Engulfment (34% of fatalities) Causes of Death (NIOSH)

Oxygen-deficient atmospheres Oxygen is consumed Gases displace oxygen

Combustible atmospheres Flammable gas, vapor or dust Oxygen enriched Combustible concentrations are far above safe toxic exposure

Toxic atmospheres Product stored in the space Activity in the confined space Sources outside the confined space

Engulfment Bridging Slumping Hang-up Rat hole

Safety and Physical hazards Temperature extremes Converging walls or floors Mechanical hazards Electrical hazards Noise? Falls - slick/wet surfaces Falling objects

Initial Atmospheric testing Oxygen Oxygen meters  Electro-chemical detectors  Instrument displays % Oxygen Minimum 19.5% O 2 (OSHA limit) Test oxygen first

Initial Atmospheric testing Combustible gases and vapors Combustible gas meters,  “Heat of combustion" meters  Combustible gas meters need oxygen to work  Instrument displays Percent Lower Explosive Limit (LEL)  (OSHA uses the term Lower Flammable, LFL) No more than 10% LFL (OSHA) Combustible dusts No more than LFL (OSHA) LFL at approx. 5 foot visibility

Initial Atmospheric testing Toxic gases and vapors Toxic gas meters Electrochemical detectors Detector tubes, etc. No more than PEL (TLV, etc.) Toxic agent may cause injury or impair escape (OSHA)

Additional atmospheric testing After ventilating the space Upon first entry Continual monitoring if conditions could change Personal alarms (for entrants) Periodic re-testing

Instruments for confined spaces Combination instruments commonly used Multi-gas, LEL, Oxygen Instruments must be properly calibrated Users must be trained

Ventilation Inerting Inert gas displaces oxygen (to control flammable hazard) IDLH hazard! Natural ventilation Wind Convection

Ventilation Mechanical Ventilation Compressed air May be suitable for small spaces Venturi blowers make more efficient use of compressed air

Ventilation Air mover at opening Portable ventilation system

Ventilation Ventilation strategies Supply mode Exhaust Mode Simultaneous supply and exhaust Displacement ventilation  Removes hazard before entry  Minimum 10 air changes (AC) Dilution ventilation reduces hazard during entry

Ventilation Recommended air changes Contaminant reduction Conditions xgood mixing and negligible contaminant release xpoor mixing or significant contaminant release xpoor mixing and significant contaminant release (ventilation alone may not be adequate) Negligible air movement and high contaminant release B Adapted from McManus, Safety and Health in Confined Spaces,1999

Isolation Tag and lock out circuits and lines Disconnect drives and linkages Secure moving parts

Isolation Blank and bleed lines "Blind" flanges "Double Block and Bleed "

Ignition, electrical Ignition control Non-sparking tools Classified electrical equipment ("Explosion proof") Electrical control Grounding Ground Fault Circuit Interrupters Isolating transformers

Personal protective equipment Atmosphere supplying respirators

Personal protective equipment Air purifying respirators Protective clothing

Retrieval devices Retrieval systems Safety belt/harness, lanyards, winch Required for top entry (OSHA) Prepare for rescue before entry

Standby/Rescue Communications Never enter confined spaces alone! Outside monitor at all times Continuous communication with entrants Rescue Rescue team on standby Monitor summons help Never attempt an unplanned confined space rescue!

Confined Space Programs Identify confined space hazards Find and evaluate spaces Labels, signs

Confined Space Programs Confined Space Entry Permit Test space before entry Specify precautions and conditions and duration of permit Sign permit and post on site Permit cancelled at end of job or if conditions change

OSHA, General Industry , Permit required confined space Scope and application( (a) Definitions( (b)  Confined Space: Large enough to enter Limited entry or exit Not designed for continuous occupancy  Permit required confined space.-a confined space with: Hazardous atmosphere potential Potential for engulfment Inwardly converging walls Any other recognized safety hazard

OSHA, General Industry General requirements( (c) Evaluate workplace Post signs Keep employees from entering, -or- Establish entry program Alternate procedures for spaces where ventilation alone is adequate to control hazard Re-evaluate as necessary Re-classify spaces as necessary Employer coordinates with contractors Contractors coordinate with employer

OSHA, General Industry OSHA Permit-required confined space program, (d) Prevent unauthorized entry Identify and evaluate before entry Develop means and procedures for safe entry Provide equipment, training Evaluate permit space conditions  Employee observation  Inform employees of result

OSHA, General Industry OSHA Permit-required confined space program, (d), continued Provide outside attendant Provisions for multiple spaces (single attendant) Designate persons and roles Rescue and emergency procedures System for entry permits Procedures for contractors Procedures to conclude the entry Review to correct deficiencies Review and revise the program

OSHA, General Industry Permit system, (e) Procedures before entry Permit must be signed Permit available to entrants Duration specified Canceling the entry Retained for at least l year

OSHA, General Industry Requirements for the entry permit, (f) Space Purpose Date and Duration Personnel Supervisor Hazards Control measures Acceptable entry conditions Test results Rescue provisions Required equipment Other information

OSHA, General Industry Training, (g) Provide all training needed When to provide training Establish employee proficiency Certify training accomplished Duties of entrants, (h) Duties of attendants, (i) Duties of supervisors, (j) Rescue, (k)

OSHA, General Industry Appendix A - Flow Chart Appendix B - Procedures for Atmospheric testing Appendix C - Examples of Confined Space Programs Appendix D - Sample Permits Appendix E - Sewer System Entry