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CONFINED SPACE ENTRY. Confined Space Entry. Construction Industry Standard 1926.21(b)(6) General Industry Standard 1910.146 Best Practices for all Industries. Typical Confined Spaces. Boiler, Degreaser, Furnace Pipeline, Pit, Pumping Station Reaction or Process Vessel, Mills
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Confined Space Entry Construction Industry Standard 1926.21(b)(6) General Industry Standard 1910.146 Best Practices for all Industries
Typical Confined Spaces • Boiler, Degreaser, Furnace • Pipeline, Pit, Pumping Station • Reaction or Process Vessel, Mills • Septic Tank, Sewage Digester • Silo, Storage Tank, Barges • Sewer, Utility Vault, Manhole • Trenches, Shafts, Caissons
Hazards of Confined Spaces • Oxygen Deficient Atmospheres (<19.5%) • Oxygen Enriched Atmospheres (>23.0%) • Flammable Atmospheres (>10% LEL) • Toxic Atmospheres (>10-ppm H2S, >35-ppm CO) • Temperature Extremes • Engulfment Hazards • Noise, Slick/Wet Surfaces, Falling Objects • Sloping surfaces that might prevent escape
Oxygen Deficient Atmospheres 19.5 % Minimum acceptable oxygen level. 15 - 19% Decreased ability to work strenuously. Impair coordination. Early symptoms. 12-14% Respiration increases. Poor judgment. 10-12% Respiration increases. Lips blue. 8-10% Mental failure. Fainting. Nausea, Unconsciousness, Vomiting. 6-8% 8 minutes - fatal, 6 minutes - 50% fatal in 4-5 minutes - possible recovery. 4-6% Coma in 40 seconds. Death.
Oxygen Enriched Atmospheres • Oxygen level above 23.0%. • Causes flammable and combustible materials to burn violently when ignited. • Hair, clothing, materials, etc. • Oil soaked clothing and materials. • Never use pure oxygen to ventilate. • Never store or place compressed tanks in a confined space.
Flammable Atmospheres • 2 Critical Factors: • Oxygen content in the air sufficient to allow burning • Presence of a flammable gas, vapor, or dust (visibility of 5’ or less) • Proper air/gas mixture can lead to explosion • A rapidly burning substance can actually result in an explosion when contained within a confined space • Typical Ignition Sources: • Sparking or electric tool • Welding / cutting operations • Smoking
Toxic Atmospheres • Product stored in a confined space: • Gases released when cleaning • Materials absorbed into walls of confined space • Decomposition of materials in the confined space • Work performed in a confined space: • Welding, cutting, brazing, soldering • Painting, scraping, sanding, degreasing • Sealing, bonding, melting • Areas adjacent to a confined space • Gases may follow contour of ground and seep into confined space
Hydrogen Sulfide • Decomposition of materials / human waste. • Rotten egg odor at low concentrations • Possibly no warning at high concentrations Conc. (ppm) EffectTime 10 Permissible Exposure Level 8 Hours 50 - 100 Mild Irritation - eyes, throat 1 Hour 200 - 300 Significant Irritation 1 Hour 500 -700 Unconsciousness, Death 1/2 - 1 Hour >1000 Unconsciousness, Death Minutes
Carbon Monoxide • Odorless, Colorless Gas • Combustion By-Product • Quickly collapse at high concentrations Conc. (ppm) EffectTime • 50 Permissible Exposure Level 8 Hours • 200 Slight headache, discomfort 3 Hours • 600 Headache, discomfort 1 Hour • 1000-2000 Confusion, nausea, headache 2 Hours • 1000-2000 Tendency to stagger 1 1/2 Hours • 1000-2000 Slight heart palpitation 30 Min. • 2000-2500 Unconsciousness 30 Min.
Temperature Extremes • Extremely hot or cold temperatures • Steam cleaning of confined spaces • Humidity factors • Extremely cold liquids • Work processes inside the confined space can increase temperature extremes • Personal protective equipment
Engulfment Hazards • Loose, granular materials stored in bins and hoppers (i.e., grain, sand, coal, etc.) • Crusting and bridging below a worker • Flooding of confined space • Water or sewage flow
Other Hazards • Noise • Amplified due to acoustics within the space • Damaged hearing, affects communication • Slick / Wet Surfaces • Slips and falls • Increased chance of electric shock • Falling Objects • Topside openings expose workers inside confined space to falling objects
How to Identify Confined Spaces • Limited Openings for Entry and Exit • Unfavorable Natural Ventilation • Not Designed for Continuous Worker Occupancy
Limited Openings for Entry/Exit • Openings as small as 18-inches in diameter • Any part of the body crossing the plane of the opening is considered entry of the confined space • Difficult to enter with SCBA or other life-saving equipment • Difficult to remove downed worker in folded up or bent over position • Exit from large openings may be difficult due to presence of ladders, hoists, etc.
Unfavorable Natural Ventilation • Lack of air movement in and out of the space can create an atmosphere much different than the outside atmosphere • Deadly gases can be trapped inside • Organic materials can decompose • May not be enough oxygen due to presence of other gases or chemical reactions, such as rusting
Not Designed for Continuous Worker Occupancy • Most confined spaces are not designed to enter and work in on a regular basis • Designed to store a product • Enclose materials or processes • Transport products or substances • Occasional worker entry for inspection, repair, cleanup, maintenance, etc.
Dangerous Combinations • Presence of all three confined space characteristics can complicate the situation. • Working in and around the confined space can increase hazards for entry personnel. • Rescue operations must be available during entry. • Worsened conditions due to work activities: • Welding and cutting, use of bonding agents • Cleaning with solvents, use of other chemicals • Use of gas-powered equipment
* Space large enough to enter & * Limited or restricted entry or exit & * Not designed for continuous worker occupancy NO Not a confined space YES Permit- Required Confined Space Non- Permit Required Space Hazardous Atmosphere or Engulfment Hazard YES NO or Configuration Hazard or Any other recognized serious hazard Categorizing Work Space Confined space
Three Types of Confined Spaces • Non-Permit Required Confined Space • No hazardous atmosphere • Permit Required Confined Space • Reclassified Permit Required Confined Space
Non-Permit Entry • No hazards OR • Able to control airborne chemical contaminant concentrations using ventilation • Hazard source controlled/neutralized/removed • Written Supervisor approval required for re-entry after hazard correction
Permit Required Confined Space • Permit Required Confined Space • PRCS – Permit Required Confined Space • Contains or has the POTENTIAL to contain a hazardous atmosphere • Contains material with the potential for engulfment (i.e., water, grain) • Internal configuration for trapping or asphyxiation • Contains any other recognized SERIOUSsafety/health hazard
Confined Space Entry • Survey workplace for confined spaces • Inspect and test confined space to determine if permit or non-permit confined space • Isolate confined space from other employees and non-employees • Perform all activities according to written plan and permit
Equipment Required • Testing And Monitoring • Multi-Gas Meter (Oxygen, Flammable Gas, Toxic Gases) • Ventilating • Fans • Communications • Radios • Cell Phones • Hand Signals • Lighting, Barriers, And Shields • Safe Ingress And Egress • Rescue And Emergency • Personal Protective Equipment (PPE) • Respiratory Protection • Specific Equipment Needed
Testing the Atmosphere • Verify presence of safe work atmosphere prior to entry, and periodically thereafter • Test all areas of a confined space • Top, Middle, Bottom • Methane is lighter than air • Carbon monoxide is heavier than air • Hydrogen sulfide is heavier than air • Oxygen deficiency (<19.5%)
Order of Testing • First - Oxygen Presence And Amounts • Second - Flammables • Third - Toxics • Fourth - Others
Ventilation • Best solution to correct problems if the source of the problem cannot be removed • Must be aware of hazards you are trying to correct in the confined space • Air intake in a safe location to draw fresh air only • Continuous ventilation whenever possible • Retest the confined space before entry
Isolation • Lock and tag out electrical sources • Blank and bleed pneumatic and hydraulic lines • Disconnect mechanical drives and shafts • Secure mechanical parts • Blank sewer and water flow • Lock and tag out shutoff valves
Retrieval Equipment • Retrieval line and body harnessmustbe used, unless: • Use makes entry more hazardous -OR- • Use would not contribute to non-entry rescue • Retrieval lines must be secured/tied outside of the space
Mechanical Lifting Devices • Stable anchor points • Existing overheads • Tripods, etc. • Must be used: • Vertical entries >5 feet deep • Attached to retrieval line/body harness
Qualified PRCS Entry Team • Authorized Entrant • Persons trained and authorized by permit to enter confined spaces • Safety Attendant • Person stationed outside of the space. The “guardian angel.” • Entry Supervisor • Fills out PRCS permit • PRCS Permit - Formal written document which authorizes personnel to enter and perform a specific operation
Emergency Rescue • Call 911 in the event of an emergency in a confined space that requires rescue services • Emergency rescue services are provided by local Fire Departments and associated agencies • OCC employees should not attempt to rescue if it requires entry of the confined space
Summary All persons involved in Permit Required Confined Space Entry must be qualified: Supervisor Safety Attendants Entrants Rescue Team - Specialized training involved Confined spaces are dangerous places Know how to control or eliminate hazards