CONFINED SPACE ENTRY
What is a Confined Space?
A space that:
• Is large enough and so configured that an employee can enter bodily and perform work;
• Has limited or restricted means of entry or exit;
• Is not designed for continuous human occupancy.
• Can represent a risk for health and safety of anyone who enters, due to one or more of the following factors:
– Its construction, location or atmosphere
– the materials in it.
– work activities being carried out in it, or the
– mechanical, process and safety hazards present
• Unfavorable Natural Ventilation
Typical Confined Spaces
• Boiler, Degreaser, Furnace
• Pipeline, Pit
• Reaction or Process Vessel,
• Septic Tank, Sewage Digestor
• Silo, Storage Tank, Barges
• Sewer, Utility Vault , Manhole
• Trenches, Shafts etc
Hazards in confined space
• Poor air quality:
• Chemical exposures .
• Fire Hazard.
• Process-related hazards such as residual chemicals, release of contents of a supply line.
• Noise.
• Safety hazards such as moving parts of equipment, structural hazards, entanglement, slips, falls.
• Radiation.
• Visibility.
• Biological hazards.
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
4-5 minutes - possible recovery.
4-6% Coma in 40 seconds. Death
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
Why is it important to ventilate confined space?
• Ventilation helps to:
• • Provide adequate oxygen to the air in the space.
• • Control atmospheric contaminants.
• • Prevent fire and explosion hazards.
• • Control heat and humidity.
• Welding, cutting, burning, and continuous brazing generate hazardous fumes and dusts that can be more effectively removed by local exhaust ventilation systems at or near the point of generation.
Ventilate the Confined Space
• Use mechanical ventilation:
• Natural ventilation (natural air currents) is usually not reliable and not sufficient to maintain the air quality. Mechanical ventilation (blowers, fans) is usually necessary to maintain air quality.
• If mechanical ventilation is provided, there should be a warning system in place to immediately notify the worker in the event of a hazard or a failure in the ventilation equipment
• Care should be taken to make sure the air being provided by the ventilation system to the confined space is 'clean'.
• Ease of air movement throughout the confined space should be considered because of the danger of pockets of toxic gases still remaining even with the use of mechanical ventilation.
• Do not substitute oxygen for fresh air. Increasing the oxygen content will significantly increase the risk of fire and explosion.
• The use of mechanical ventilation should be noted on the entry permit.
Precaution in confined space
• Information, Instruction, and training: No person should enter into a confined space without adequate training or not having made familiar with both equipments and procedures.
• Isolation: The confined spaces must be isolated from all possible external sources of danger to person entering.
• Cleaning: There is a verity of methods of cleaning the inside of confined spaces to remove all hazardous solid, liquids or gas.
• Purging and ventilation; Air purging and ventilation may be carried out by removing cover, opening inspection doors, and allowing ordinary air circulations, Forced ventilation is to be given wherever required.
• Selection of personal: Select the right person to work in confined space. Person must be physically fit.
• Communication: Adequate and effective communications must exist between those inside and those outside the confined space.
• Safety Equipment: Ensure that the PPE required must be supplied to men and they are worn.
• Fire safety: Where there is a risk of fire appropriate fire extinguisher may need to be kept in the confined space at the entry point.
• Access and egress and entry log: A safe way in and out of the confined space should be provided. Suitable signs must be placed at the access entry point. Confined space entry log to be maintained and displayed at the entrance. There must be a stand by man at the confined space entry point.
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CONFINED SPACE "JSA"
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