In which case is the IOPP Certificate of an inspected vessel NOT invalidated?

Correct Answer: Option B — The required oily-water separator malfunctions.

An IOPP Certificate remains valid despite equipment malfunctions, provided they are addressed. However, the certificate is invalidated if the vessel changes registry, fails to undergo mandatory surveys within the required timeframes, or if the equipment is modified in a way that violates the original certification standards.