CHEMCO Exit Exam • Set 8 Question 11 of 30

What is the maximum percent of oxygen, by volume, allowed to be maintained in the cargo tanks prior to the commencement of crude oil tank washing?

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Direct Answer

Option B: 8%

MARPOL Annex II and the IBC Code mandate that prior to Crude Oil Washing (COW), the oxygen content in cargo tanks must not exceed 8% by volume. This level ensures that the atmosphere within the tank remains below the lower flammable limit, mitigating the risk of ignition.

All Options

8% (Correct Answer)

10%

12%

Detailed Explanation & Context

Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • Advanced Training for Chemical Tanker Cargo Operations (CHEMCO).

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