HSE : IQA : Confined Space

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The Safety Interview Question & Answer

Topic : Confined Space

1. What is Confined space?
• Any area which is not normally occupied by personnel having limited means of entry or exit where there can be oxygen deficiency or accumulation, the presence of flammable or toxic gases.
• Like working inside pipes, vessels, boiler, Column, tanks, manholes, excavation deeper than 1.2m etc.
2. Who is stand by man/ whole watcher or entry attendant?
• A trained employee deployed at the entry point of confined space to monitor entrants, prevent the unauthorized entry of confined space and notify emergency response team in case of emergency. His duties include but not limited to maintaining log sheet of entry (Those who enter and exit confined space will sign the entry log sheet).
• Maintain communication with entrants (Through voice or other communication means).
• Report emergency if any.
3. What are the hazards in confined space?
1. Hazards in confined space.
1. Oxygen deficiency or accumulation.
2. Presence of flammable or toxic gases (Like hydrogen sulfide, CO, LEL).
3. Noise.
4. Fire.
5. Falling materials.
6. High temperature.
7. Limited access and egress.
8. Poor visibility.
9. Dust.
10. Slip, trip and fall.
4. Tell me procedure/ requirements of confined space?
1. Confined space permit and relevant permit (hot work or cold work) shall be obtained.
2. JSA should be available.
3. Install Signage (No unauthorized entry).
4. Proper ventilation shall be done to remove hazardous fumes, dust, gases etc.
5. Competent personal shall be deployed to monitor activities. (Confined pace supervisor).
6. Develop emergency response procedure.
7. Conduct Gas test by authorized gas tester before commencing entry.
8. Stand by man should be deployed and maintain confined space log sheet.
9. Provide proper communication means.
10. SCBA should be provided at entry point to deal with any emergency.
11. Air pressure horn need to be provided.
12. Workers should be trained.
13. Proper PPE should be provided and used.
14. Ensure proper lighting.
15. Maintain good housekeeping.
16. Compressed gas cylinders are not allowed inside confined space.
17. Oxygen should not be less than 20 percent and more 23.5 percent.
18. CO should be less than 35 PPM.
• Note: Try to avoid if possible, the use of CO2 extinguishers in confined spaces as it will cause oxygen deficiency.
5. Who can perform Gas test?
• Authorized gas tester.
6. What is IDLH?
• IDLH means Immediate Dangerous to Life and Health.
• For instance, IDLH of Hydrogen sulfide is 100 PPM.
7. Which gases are normally monitored in confined space?
• H2S, CO, Oxygen and LEL.
8. Who can perform gas test?
• Authorized gas tester.
9. What is the difference between MX4 and T40 Rattler?
• MX4 is a multi-gas detector and detects (H2S, O2, LEL, CO) while T40 Rattler is personal H2S monitor.
10. Who will rescue personal from Confined space?
• Emergency response/rescue team.
11. What should we do if there is oxygen deficiency?
• We can use SCBA (Self-Contained Breathing Apparatus) or SAR.
12. What should we do if oxygen enriched goes more than 23.5%?
• Use ventilation system unless brought to acceptable level (Less than 23.5%).
13. What are the properties of Carbon monoxide? 
• Carbon monoxide is toxic, color less, odorless, and tasteless gas.
14. How CO harm our body?
• Carbon monoxide is harmful when breathed because it displaces oxygen and deprive heart, brain and other important organ from oxygen.
• Symptoms when exposed to CO may include Nausea, headache, dizziness,
• drowsiness and fatigue etc.
• (CO detector shall continuously monitor the atmosphere when hot work is in progress in confined space).
15. You said O2 should not be less than 20% and more than 23.5%.Why?
• Oxygen less than 20 percent is harmful and pose life threat to individuals and will result in death or unconsciousness.
• Oxygen enriched environment (more than 23.5%) increase the chance of ignition (fire).
16. What is confined space?
• Any enclosure having a limited means of entry & exit and it is not designed for continuous occupancy.
• There will be a presence of any hazardous substances such as flammable and toxic gases, oxygen deficiency, hot or humid atmosphere or any combination of it.
• Examples: Process vessels, Tanks, Bins, Stacks, Large pipe, Duct, Pits & Trench etc. Any excavation with depth more than 1.2 meter. 
17. What are the Confined Space Hazards? 
• A confined space may have one or combination of the following hazards:
• Oxygen deficiency
• Presence of flammable, combustible or pyrophoric materials (HC, Sludge etc.)
• Presence of toxic gases, corrosive or hazardous materials (H2S, Co, NH3 etc.)
• Poor illumination, Ventilation & Communication.
• High temperature and humidity.
• Limited entry & exit / Restricted access.
• Restricted movement inside.
• Falling / Tripping hazards
• Presence of reactive or self-igniting material.
• Hazard due to electricity or moving machinery.
• Hazard due to pressurized fluid.
• Hazard due to nature of work carried out inside confined space. 
18. What is the procedure for entering a confined space hazards? OR What are the important PRECAUTIONS for confined space? 
• Procedure for entering confined space:
• Permit must be procured form operations, making sure of the following.
• Complete isolation of the space to be entered.
• Draining, depressurization and purging or cleaning should be performed.
• Gas test should be conducted to ensure no hazardous atmosphere is present.
• Space ventilation.
• A Pre task meeting must be conducted with all authorized entrants prior to entering confined space.
• The attendant (Stand by man) shall be assigned at the entrance to maintain communication with employees working inside to ensure their safety. A log book shall be maintained at the entrance to keep track of the people inside the space.
• Safety attendant must be trained and authorized to use gas testing equipment.
• Entrants must wear body harness, and if necessary a life line be attached to the harness to avoid entry-rescue.
• Lighting should be provided, if necessary a maximum of 24 volts, lighting should be used attached a GFCI.
• Only intrinsically safe or explosion-proof equipment shall be used inside.
• Depending on the situation, emergency rescue team may be put on standby.
• If an emergency occurs within the confined space, the standby person must not enter it until rescue team arrived.
• Barricade the area with warning sign board. 
19. What you know about working in a confined space entry? OR Explain about confined space entry? 
• Any enclosure having a limited means of entry & exit and it is not designed for continuous employee occupancy.
• Before entering in the confined space, must need to obtained a confined space entry work permit, make sure that all required isolation being done.
• Frequently gas test is to be carried out to confirm that area is free of toxic gas or flammable atmosphere.
• If the area is contaminated or it has oxygen deficiency the provided BA sets or air line respiratory system.
• Conduct pre-task meeting for the employees who will be entering inside the confined area and get there signature to conform that they are aware of the hazards and safety measures.
• The attendant (Stand by man) to assigned at the entrance. A log book shall be maintained at the entrance to keep track of the people inside the space. The attendant shall not be assigned to other duties. If an emergency occurs within the confined space, the standby person must not enter it until rescue team arrived.
• The entering people should use body harness with lifeline for the emergency rescue purpose.
• Any required electrical lighting or tools should not exceed more than 24 volts and attached with GFCI / ELCB. It should be intrinsically safe or explosive proof.
• Barricade the area with warning sign board.