STSC Confined Space Entry Procedures 2 — Questions and Answers
Question 1: What is the minimum air monitoring requirement before entering a permit-required confined space?
- Test only for oxygen levels
- Test for oxygen, flammable gases, and toxic air contaminants (Correct answer)
- Test for CO2 levels only
- Visual inspection is sufficient
Correct answer: Test for oxygen, flammable gases, and toxic air contaminants
OSHA 29 CFR 1926.1203 requires testing for oxygen content, flammable gases/vapors, and toxic air contaminants before entry.
Before any worker enters a permit-required confined space, the atmosphere must be tested in this order: oxygen content (acceptable range 19.5%–23.5%), flammable gases/vapors (less than 10% of LEL), and toxic air contaminants (at or below PELs). Testing must be performed by a qualified person using calibrated equipment.
Question 2: Who is responsible for monitoring conditions and maintaining communication with authorized entrants in a permit-required confined space?
- The entry supervisor
- The attendant (Correct answer)
- The safety officer
- The foreman
Correct answer: The attendant
The attendant remains outside the space, monitors conditions, and maintains communication with authorized entrants.
Under OSHA 29 CFR 1926.1209, the attendant must remain outside the confined space, continuously maintain accurate count and identity of authorized entrants, communicate with entrants as necessary, order evacuation if a hazardous condition is detected, and summon rescue and emergency services if needed. The attendant must not perform any other duties that interfere with primary responsibilities.
Question 3: When must a confined space entry permit be cancelled?
- Only at the end of the work shift
- When all authorized entrants have exited the space (Correct answer)
- When the entry supervisor leaves the site
- After 8 hours regardless of work completion
Correct answer: When all authorized entrants have exited the space
The entry permit must be cancelled when the authorized entrants have exited and no further entry is required under that permit.
Per OSHA 29 CFR 1926.1206(e), the entry supervisor must cancel the permit when the entry operation covered by the entry permit has been completed or when a condition not allowed under the entry permit arises. Cancelled permits must be retained for at least 1 year to help identify problems with the permit program.
Question 4: What rescue method is preferred for confined space rescue operations?
- Entry rescue by a trained rescue team
- Non-entry retrieval using a retrieval system (Correct answer)
- Calling 911 for fire department assistance
- Waiting for specialized hazmat team
Correct answer: Non-entry retrieval using a retrieval system
Non-entry retrieval is the preferred method as it eliminates the need for rescuers to enter the hazardous space.
OSHA 29 CFR 1926.1211 states that employers must develop and implement rescue procedures. Non-entry retrieval systems (chest or full-body harness with retrieval line connected to a mechanical device or fixed point) must be used whenever feasible. This method is preferred because confined space emergencies have resulted in many rescuer fatalities when entry rescue was attempted without proper precautions.
Question 5: A space that has the potential to become permit-required under certain conditions is classified as:
- An alternate-entry confined space (Correct answer)
- A non-permit confined space
- A reclassified confined space
- A transitional confined space
Correct answer: An alternate-entry confined space
Alternate-entry confined spaces may become permit-required when conditions change, requiring a re-evaluation.
Under OSHA 29 CFR 1926.1203, a confined space that does not currently contain or have the potential to contain any serious hazard may be reclassified as a non-permit confined space. Conversely, if conditions change (e.g., introduction of a hazardous substance), a space must be reclassified as permit-required. Entry supervisors must continuously evaluate whether conditions remain acceptable.
Question 6: Continuous forced-air ventilation in a confined space must direct fresh air to:
- The space entrance only
- All areas of the space, especially where workers are present (Correct answer)
- The highest point of the space
- The exhaust outlet to remove contaminants
Correct answer: All areas of the space, especially where workers are present
Ventilation must reach all areas where workers are present to ensure acceptable atmospheric conditions throughout.
OSHA requires that forced-air mechanical ventilation be directed to ventilate the immediate areas where workers are present and continue until all workers have exited the space. The air supply must be from a clean source and not increase the hazards in the space (e.g., avoid using pure oxygen for ventilation as it creates a fire hazard). Atmospheric conditions must be re-tested after ventilation and before entry.
STSC Confined Space Entry Procedures 2
What is the minimum air monitoring requirement before entering a permit-required confined space?