Confined Space Safety Interview: 50 Questions and Sample Answers
1. What is a confined space?
Answer: A confined space is an enclosed or partially enclosed area with limited entry/exit, not designed for continuous occupancy, and may pose hazards such as toxic gases, oxygen deficiency, or engulfment.
2. Can you give examples of confined spaces?
Answer: Yes, examples include tanks, silos, pits, tunnels, manholes, vaults, boilers, and pipelines.
3. Why is confined space safety important?
Answer: Because confined spaces can contain hazardous atmospheres, limited oxygen, and pose risks like entrapment, toxic exposure, and suffocation.
4. What are the main hazards in confined spaces?
Answer: – Oxygen deficiency
- Toxic gases and vapors
- Flammable atmospheres
- Engulfment (sand, grain, water)
- Restricted movement
5. What is a permit-required confined space?
Answer: A space that has one or more of the following hazards:
- Potential for hazardous atmosphere
- Engulfment risk
- Internal configuration trapping a person
- Other serious hazards (e.g., heat, electricity, machinery)
6. What is a non-permit confined space?
Answer: A confined space that does not contain or have the potential to contain hazardous conditions.
7. What is a confined space entry permit?
Answer: A written authorization ensuring all safety measures are in place before entering a confined space.
8. Who is responsible for issuing a confined space entry permit?
Answer: The permit issuer or safety officer, after assessing hazards and ensuring control measures.
9. What information is included in a confined space permit?
Answer: – Location and description of the confined space
- Hazard assessment results
- Required PPE and equipment
- Entry procedures and rescue plans
- Names of authorized entrants and attendants
10. Who are the key personnel in confined space entry?
Answer: – Authorized entrant
- Attendant (standby person)
- Entry supervisor
- Rescue team
11. What are the responsibilities of an authorized entrant?
Answer: – Follow entry procedures
- Use required PPE
- Communicate with the attendant
- Exit immediately if hazards arise
12. What are the duties of an attendant?
Answer: – Monitor entrants
- Maintain communication
- Call for emergency help if needed
- Prevent unauthorized entry
13. What is the role of an entry supervisor?
Answer: – Ensure all safety precautions are followed
- Verify permit requirements
- Cancel or stop work if conditions change
14. What is atmospheric testing in confined spaces?
Answer: Testing the air inside a confined space for oxygen levels, toxic gases, and flammable vapors before entry.
15. What gases are commonly tested in confined spaces?
Answer: – Oxygen (O₂)
- Carbon monoxide (CO)
- Hydrogen sulfide (H₂S)
- Explosive gases (LEL – Lower Explosive Limit)
16. What is the safe oxygen level for confined space entry?
Answer: Between 19.5% and 23.5% oxygen.
17. What happens if oxygen levels are too low?
Answer: Dizziness, confusion, unconsciousness, and suffocation can occur.
18. What is the lower explosive limit (LEL)?
Answer: The minimum concentration of a flammable gas required to ignite.
19. What should be done if a confined space has a hazardous atmosphere?
Answer: – Ventilate the space
- Use proper PPE and respiratory protection
- Retest the atmosphere before entry
20. What is forced ventilation, and why is it used?
Answer: Blowing fresh air into a confined space to remove hazardous gases and improve oxygen levels.
21. What type of respiratory protection is used in confined spaces?
Answer: – Air-purifying respirators (for known contaminants)
- Self-contained breathing apparatus (SCBA) (for unknown or oxygen-deficient areas)
22. Why is continuous monitoring required in confined spaces?
Answer: Conditions can change suddenly, creating life-threatening hazards.
23. What are common emergency situations in confined spaces?
Answer: – Oxygen deficiency
- Toxic gas exposure
- Fires or explosions
- Entrapment or engulfment
24. What should be included in a confined space rescue plan?
Answer: – Rescue team availability
- Emergency contact details
- Rescue equipment (harnesses, tripods, breathing devices)
- Proper training for rescuers
25. What are the types of confined space rescues?
Answer: – Self-rescue (entrant exits alone)
- Non-entry rescue (rescuer does not enter, uses retrieval systems)
- Entry rescue (trained team enters to save worker)
26. What equipment is required for confined space entry?
Answer: – Gas detectors
- Ventilation fans
- Harness and lifeline
- Personal protective equipment (PPE)
- Escape breathing apparatus
27. What personal protective equipment (PPE) is needed for confined space entry?
Answer: – Gloves
- Hard hats
- Eye protection
- Respiratory protection
28. How can engulfment hazards be controlled?
Answer: – Use barriers to prevent materials from shifting
- Monitor confined space atmosphere continuously
29. Why is a confined space entry log maintained?
Answer: To keep track of who entered, time spent, and conditions inside.
30. What is lockout/tagout (LOTO), and why is it used in confined spaces?
Answer: LOTO ensures hazardous energy sources are shut off and cannot be re-energized while workers are inside.
31. Why is training important for confined space workers?
Answer: Training helps workers recognize hazards, use equipment correctly, and respond to emergencies.
32. What is an entry retrieval system?
Answer: A harness and lifeline system used to pull a worker out in case of an emergency.
33. What should be done before re-entering a confined space?
Answer: – Re-test the atmosphere
- Ensure ventilation is working
- Confirm permit validity
34. How can heat stress be managed in confined spaces?
Answer: – Take breaks
- Stay hydrated
- Use cooling vests
35. What is inerting, and when is it used?
Answer: Replacing oxygen with a non-reactive gas (e.g., nitrogen) to prevent explosions in flammable spaces.
36. How often should confined space training be conducted?
Answer: At least annually, or when new hazards arise.
37. What is the main cause of confined space fatalities?
Answer: Lack of oxygen and toxic gas exposure.
38. What should an attendant never do?
Answer: Never enter the confined space to rescue without proper equipment and backup.
39. What are the requirements for confined space lighting?
Answer: Use explosion-proof, low-voltage, or intrinsically safe lighting.
40. What is a standby person in confined space safety?
Answer: A person outside the space monitoring the entrant and alerting rescuers if needed.
41. Why is a pre-entry meeting necessary?
Answer: To review hazards, responsibilities, and emergency procedures.
42. What is the difference between a confined space and an enclosed space?
Answer: Confined spaces may contain hazards, while enclosed spaces do not always pose risks.
43. How should tools be used inside confined spaces?
Answer: Use non-sparking, insulated, or explosion-proof tools to prevent ignition hazards.
44. What should be done if a confined space becomes unsafe?
Answer: Evacuate immediately and reassess hazards.
45. What is the role of a gas monitor in confined spaces?
Answer: Detect hazardous gases and ensure safe breathing conditions.
46. Why should confined space entries be minimized?
Answer: To reduce worker exposure to hazards.
47. What should be done after exiting a confined space?
Answer: – Conduct a debriefing
- Inspect equipment
- Close permits
48. What are confined space entry best practices?
Answer: – Follow entry procedures
- Use proper PPE
- Monitor air quality
49. How can confined space hazards be eliminated?
Answer: Through engineering controls, ventilation, and proper work procedures.
50. What is the most important rule for confined space entry?
Answer: Never enter without proper training, authorization, and equipment.
Confined Space JSA (Job Safety Analysis) | Free Download
Confined Space Rescue: Planning and Emergency Procedures
