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Confined Spaces.

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Presentation on theme: "Confined Spaces."— Presentation transcript:

1 Confined Spaces

2 Confined Space Entry Construction Industry Standard 1926.21(b)(6)
General Industry Standard Best Practices for all Industries

3 Typical Confined Spaces
Boiler, Degreaser, Furnace Pipeline, Pit, Pumping Station Reaction or Process Vessel, Mills Septic Tank, Sewage Digestor Silo, Storage Tank, Barges Sewer, Utility Vault, Manhole Trenches, Shafts, Caissons

4 The Three Elements of a Confined Space
Is large enough and so configured that an employee can bodily enter and perform assigned work; and Has limited openings for entry and exit, and Is not designed for continuous worker occupancy

5 Categorizing Work Space
* Space large enough to enter &; * Limited or Restricted entry or exit &; * Not designed for continuous worker occupancy. NO Not a confined Space YES Confined Space Permit- Required Confined Space Hazardous Atmosphere Non Permit Required Space Or Engulfment Hazard YES NO Or Configuration Hazard Or Any other recognized serious hazard

6 Limited Openings for Entry/Exit
Openings as small as 18 inches in diameter. 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.

7 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.

8 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.

9 Dangerous Combinations
Presence of all three confined space characteristics can complicate the situation. Working in and around the space. Rescue operations during emergencies. 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

10 Hazards of Confined Spaces
Oxygen Deficient Atmospheres Oxygen Enriched Atmospheres Flammable Atmospheres Toxic Atmospheres Temperature Extremes Engulfment Hazards Noise, Slick/Wet Surfaces, Falling Objects

11 Oxygen Deficient Atmospheres
19.5 % Minimum acceptable oxygen level. % 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 minutes - possible recovery. 4-6% Coma in 40 seconds. Death

12 Oxygen Enriched Atmospheres
Oxygen level above 21%. 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.

13 Flammable Atmospheres
2 Critical Factors: Oxygen content in the air. Presence of a flammable gas, or vapor Presence of dust (visibility of 5’ or less) Proper air/gas mixture can lead to explosion Typical Ignition Sources: Sparking or electric tool. Welding / cutting operations. Smoking

14 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.

15 Hydrogen Sulfide Decomposition of materials. Human waste.
Rotten egg odor at low concentrations. Possibly no warning at high concentrations. PPM Effect Time 10 ppm Permissible Exposure Level 8 Hours Mild Irritation - eyes, throat 1 Hour Significant Irritation 1 Hour Unconsciousness, Death 1/2 - 1 Hour >1000 Unconsciousness, Death Minutes

16 Carbon Monoxide Odorless, Colorless Gas. Combustion By-Product.
Quickly collapse at high concentrations. PPM Effect Time 50 Permissible Exposure Level 8 Hours 200 Slight headache, discomfort 3 Hours 600 Headache, discomfort 1 Hour Confusion, nausea, headache 2 Hours Tendency to stagger 1 1/2 Hours Slight heart palpitation 30 Min. Unconsciousness 30 Min.

17 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.

18 Engulfment Hazards Loose, granular materials stored in bins and hoppers - grain, sand, coal, etc. Crusting and bridging below a worker. Flooding of confined space. Water or sewage flow.

19 Other Hazards Noise Slick / Wet Surfaces Falling Objects
Amplified due to acoustics within the space. Damaged hearing, affect communication. Slick / Wet Surfaces Slips and falls. Increased chance of electric shock. Falling Objects Topside openings expose workers inside confined space to falling objects.

20 Internal Configuration

21 Testing The Atmosphere
Verify presence of safe work atmosphere. Test all areas of a confined space. Top, Middle, Bottom Methane is lighter than air. Carbon Monoxide is the same as air. Hydrogen Sulfide is heavier than air. Oxygen Deficiency.

22 Ventilation First option to correct problems.
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.

23 Isolation Locking and tagging out electrical sources.
Blanking and bleeding pneumatic and hydraulic lines. Disconnecting mechanical drives and shafts. Securing mechanical parts. Blanking sewer and water flow. Locking and tagging out shutoff valves.

24 Respirators Air-Purifying Respirators Air-Supplying Respirators
Filter dangerous substances from the air. Must know the type and amount of hazardous substance present in the confined space. NEVER use with oxygen deficiency! Air-Supplying Respirators Deliver a safe supply of breathing air from a tank or an uncontaminated area nearby. Must be adequately monitored.

25 Permit Entry Systems Written permit signed by entry supervisor.
Verifies pre-entry precautions have been taken and the space is safe to enter. Posted at entry to confined space. Specifies apparent hazards and corrective actions taken prior to entry. Requires termination of permit when task is completed or when new conditions exist.

26 Entry Permit Requirements
Date, location, and name of confined space. Purpose of entry and known hazards. Duration of entry permit time. Authorized entrants, attendants, supervisors. Air testing results - signature of tester. Protective measures to be taken. Ventilation, Isolation, Flushing Lockout / Tagout, Purging

27 Entry Permit Requirements
Name and phone numbers of rescue and emergency services. Communication procedures. Special equipment and procedures. Personal protective equipment. Alarm procedures. Rescue equipment. Respirators.

28 Standby / Rescue Worker assigned to remain outside the confined space and be in constant contact with the workers inside. Know emergency rescue procedures. 50% of workers who die in confined spaces are would-be rescuers. Trained in use of emergency rescue equipment and PPE.

29 Training and Education
All workers who must enter confined spaces All attendants and rescue team members. Prior to initial work assignment. Retraining: Job duties change. Change in permit-space program. New hazards are present. Job performance indicates deficiencies.

30 Confined Space Rescue Training Compliance Issues

31 Most confined space fatalities are poorly trained rescuers…
Many of these heroes died because their employer unintentionally broke the law- OSHA regulations!

32 OSHA’s 3 levels of protection for confined space entrants:
1) Permitting procedure identifies hazards and addresses protective measures 2) Retrieval equipment required for quick external rescue 3) Rescue services required to be available to perform internal rescue

33 Employer shall ensure... (i) The outside rescuer can effectively respond in a timely manner to rescue summons. (ii) The outside rescuer is equipped, trained, and capable of functioning appropriately to perform permit space rescues… (iii) …rescuer is aware of the hazards… (iv) …provide access...

34 Response Vs Rescue Time...
(1) React Time: Attendant recognizes that the Entrant has a problem. (2) Contact Time: Attendant contacts the Rescue Service. (3) Response Time: Rescue Service arrives at the scene. An OSHA confined space citation was upheld in a November, 1997 case where the investigating OSHA Ind. Hyg. found that communications between the attendant and entrant in a possible IDLH atmosphere needed to be at least every minutes as opposed to every 3-4 minutes…..the administrative judge upheld the OSHA citation…..

35 Rescue Vs Response Time...
(4) Assessment Time: Size-up and strategy determination. (5) Preparation Time: Rescue equipment set-up. (6) Rescue Time: Reaching, treating, packaging, and evacuation of the victim.

36 Rescue Stand-by Goal: 4-Minute Rescue Response
Possible only if rescuers are rigged and ready while the entry is taking place. This is defined as Rescue Stand-by.

37 Rescue Available Appropriate (and Approximate!) Goals: Respond To CS Scene / 10 Minutes Reach The Victim(s) / 5-10 Minutes Later Case law update….10 minute response held to be not timely in a Nov case! This particular OSHA case used the example of if the space was IDLH that 6 minutes was too long and therefore held a 10 response time is too long. It should be noted that OSHA is referring to arrival at the site of the emergency - not at the actual CS scene…..which may take several additional minutes. The only response mode capable of reaching and viably treating the patient/victim who is not breathing in an IDLH atmosphere is Rescue Standby.

38 Choosing the Appropriate Response
Decision: Stand-by Vs. Available Each entry must be evaluated to determine the appropriate response mode. The evaluation must be done by a qualified person (rescuer and/or entry supervisor). Factors to be considered include the severity of the hazard, required PPE, and the ability of the entrant to self-rescue.

39 Timely Response, Training, and Equipment
Rescue Retrieval Ventilation & Atmospheric Monitoring Barriers Access/Egress (ladders, etc...) Lighting Communication

40 Timely Response, Training, and Equipment
Documented training by each team member via simulated rescues in every type of confined space (Rescue training) Authorized Entrant/Attendant First Aid & CPR (Blood-borne pathogens) Haz Com, PPE, Respiratory, Lockout, PSM Equipment training (Fall Protection)

41 CSR Training: Each rescue team member must be trained to safely perform all assigned rescue duties. - Rigging - Entry (claustrophobia) - PPE utilized outside the space - Equipment maintenance - Individual skills (IPE)

42 Hands-on Rescue Training:
Each member must practice simulated rescue operations at least once every 12 months in the actual PRCS or representative spaces that simulate the types of spaces based on opening size, configuration, and accessibility….

43 Rescue in Confined Space

44 What are the requirements for practice rescue exercises?
1. Practice exercise must involve the actual removal of dummies or persons from the actual permit spaces or from representative spaces. 2. Representative spaces need to simulate the types of permit spaces from which rescues may be performed with respect to: · Opening size · Configuration · Accessibility

45

46

47 Ventilation of Confined Spaces

48 Confined Space Ventilation
Confined spaces are not normally designed for convenient ventilation Must take steps to: ensure air is breathable before entering confined space maintain acceptable air quality in the confined space during entry

49 Hotwork in Confined Spaces
Presents additional ventilation challenges in confined spaces Includes torch cutting, welding, brazing and soldering, arch gouging

50 Hotwork in Confined Spaces
Remember… confined spaces concentrate hazards! Hotwork can create atmospheric hazards in confined spaces from fumes, gasses and vapors Effective ventilation sometimes may only be accomplished by mechanical ventilation

51 Natural Ventilation in Confined Spaces
“Chimney Effect” convection process created by temperature changes Occurs by sunlight heating vessel walls and air within If there is an opening in bottom and top of vessel, upward draft created

52 Natural Ventilation Problems
Confined spaces rarely experience uniform thermal conditions Various sources of heat in confined spaces human bodies lighting hotwork processes

53 Natural Ventilation Problems
Factors such as sunlight, body heat, lighting and hotwork are usually not sufficient to move enough air to provide an acceptable atmosphere

54 Use of Mechanical Ventilation
Properly installed, can reduce or eliminate respiratory protection requirements Effective engineering controls usually less dependent on worker attention than respiratory protection

55 When is ventilation necessary?
If atmosphere: contains insufficient oxygen or is oxygen rich contains flammable dusts or vapors contains hazardous or toxic vapors, mists, fumes, gases, or fibers

56 When is ventilation necessary?
If atmosphere: is subject to activities that may generate hazardous mists, vapors, fumes or gases, or may create either an oxygen deficiency or oxygen excess, and increases heat stress on workers to unacceptable levels

57 CAUTIONS Many people resist wearing PPE, including respiratory protection Tangle of supplied air hoses in vessel with many welders can present a hazard

58 Ventilation- 29 CFR 1910.252(c) Spaces that require ventilation
work space less than 16 feet high volume less than 10,000 cubic feet per welder work areas with partitions, structural barriers, or other barriers that significantly obstruct airflow

59 Ventilation- 29 CFR 1910.252 Ventilation options:
provide at least 2000 cfm of airflow for each active welder; or provide each welder with a local exhaust device local exhaust devices must be capable of maintaining a velocity of 100 fpm toward the air intake

60 Ventilation Requirements
29 CFR and 29 CFR require use of local exhaust ventilation or supplied air respiratory protection when performing hotwork using certain substances

61 Air Moving Devices Two types: Can be air, steam or electrically driven
Fans Venturi-type eductors Can be air, steam or electrically driven

62 Eductors Sometimes called “air horns”
Air powered and rely on venturi effects to move air

63 Criteria for Rating Air Movers
Free Air Delivery Effective Blower Capacity Quantity of air and air pressure required (air-driven devices) Electrical power requirements (electrically driven devices)

64 Factors Reducing Performance
Equipment components in confined space Maintenance/construction materials erected in space Obstructions in make-up air manway Insufficient number of make-up air manways

65 Factors Reducing Performance
More restrictions to overcome = less air moved Air moving into space equals amount of air leaving the space

66 Air Driven Devices- Poor Performance
Reduced pressure and volume to air driven devices from multiple users Excessively long air hoses

67 Increasing Performance
Supplemental air compressors dedicated to air mover use (air driven devices) Supplemental air compressors connected directly to plant air system Eliminate “short-circuiting” of airflow

68 Designing Ventilation Systems
Configuration, contents and tasks determine type of ventilation opening configuration properties of expected atmospheric hazards type of work being performed

69 Electrically Driven Centrifugal Fans
Designed to overcome higher static pressures Usually heavier than air-driven equipment Can be used remotely to reduce noise Due to power, can suck up debris

70 Local Exhaust Single manway vessels
Interior obstructions that create “dead spots” Lack of feasible way to attach air-moving device Work with toxic metals

71 Local Exhaust Effective only when it captures and removes welding fumes and gasses at the source as they are emitted 100 fpm capture velocity at the source of fumes or gasses

72 Local Exhaust- Considerations
Long runs reduce airflow Airflow loss minimized by use of smooth ducting with large radius bends Run flexible ducting as straight as possible Consider using plenums for multiple welders Field test flow/personal air monitors

73 Make-up air quality Mechanical ventilation uses surrounding air
Make sure the make-up air is not a source of airborne contaminants

74 Confined Spaces

75 Pre Entry Consider the following: Piping systems Electrical hazards
Illumination Ventilation Means of access Fall protection

76 Pre Entry Visual Inspection (Competent Person) Employee Training
Exchanging Information Atmospheric Testing Shipyard Competent Person Certified Marine Chemist Certified Industrial Hygienist Coast Guard Authorized Person Rescue Teams

77 Entry Atmospheric Testing Warning Signs and Labels Visual Inspection
Ventilation PPE for Entry Rescue Teams

78 Work Hot Work Cleaning


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