PSSR Exit Exam • Set 5 Question 3 of 30

Prior to entering an enclosed space, what is the minimum required oxygen content percentage by volume?

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Direct Answer

Option C: 20.9%

Normal atmospheric oxygen concentration is 20.9% by volume. Enclosed space entry requires testing for 20.9% O2, 0% LFL flammable gas, and zero toxic vapors.

All Options

16.0%

18.0%

20.9% (Correct Answer)

23.5%

Detailed Explanation & Context

Normal atmospheric oxygen concentration is 20.9% by volume. Enclosed space entry requires testing for 20.9% O2, 0% LFL flammable gas, and zero toxic vapors.

Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • Personal Safety & Social Responsibilities (PSSR).

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More Questions in PSSR Set 5

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Q1 Under MARPOL Annex I, what is the maximum allowable oil content of discharge from the bilge of a ship outside special areas while en route? Q2 What permit is mandatory before any work involving naked flames, welding, or spark-producing tools can be carried out outside the workshop? Q3 Prior to entering an enclosed space, what is the minimum required oxygen content percentage by volume? Q4 What safety precaution must be taken when a seafarer is working at height above 2 meters over an open deck or over the side? Q5 What is the primary objective of Lockout / Tagout (LOTO) procedures on board? Q6 What general emergency alarm signal is sounded on a ship's whistle and internal alarm system? Q7 Which MARPOL Annex regulates the prevention of pollution by garbage from ships? Q8 What safety document provides essential health, hazard, and emergency response information for chemicals handled on board? Q9 What action must be taken immediately if a crew member witnesses someone falling overboard? Q10 Under MARPOL Annex VI, what is the global maximum allowable sulfur content in marine fuel oil outside Emission Control Areas (ECAs) as of 2020?