Confined Space Entry Requirements Flashcards
7 cards from real CMC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Confined Space Entry Requirements flashcards as text
When multiple spaces on a vessel are interconnected through piping or ducting, what precaution is required before entry into any one space?
Answer: Blank, blind, or otherwise isolate connecting lines to prevent gas migration
Interconnected spaces must have connecting lines blanked or blinded to prevent hazardous gases from migrating during entry.
What is the role of an 'attendant' during confined space entry operations on a vessel?
Answer: To remain outside the space, monitor entrants, and initiate rescue if needed
The attendant stays outside, monitors entrants and atmospheric conditions, and initiates emergency procedures if necessary.
Under NFPA 306, which of the following spaces requires marine chemist certification before hot work can proceed?
Answer: Fuel oil tanks, cargo tanks, and spaces adjacent to them
Fuel oil tanks, cargo tanks, and adjacent spaces require marine chemist certification before any hot work is performed.
What does 'LEL' stand for and what is its significance in confined space entry?
Answer: Lower Explosive Limit — the minimum vapor concentration that can ignite
LEL (Lower Explosive Limit) is the minimum vapor-in-air concentration at which ignition can occur, and entry is prohibited above 10% LEL.
Which condition requires the marine chemist to re-test a space that was previously certified as safe?
Answer: A change in cargo, weather, or operations that could affect the atmosphere
Any change in conditions—new cargo introduction, weather changes, or altered operations—requires re-testing the space.
What is the primary purpose of a retrieval system (tripod and harness) at a confined space entry point on a vessel?
Answer: To enable non-entry rescue of an incapacitated worker
Retrieval systems allow attendants to extract incapacitated workers without requiring rescuers to enter the hazardous space.
When measuring atmospheric conditions at multiple levels within a deep tank, why is stratified sampling important?
Answer: Different gases may concentrate at different heights due to their molecular weight relative to air
Gases heavier than air (like benzene vapor) concentrate at the bottom, while lighter gases (like methane) rise, requiring testing at multiple levels.