🔍 Key Concepts

• Enclosed space / confined space hazards on ships (lack of oxygen, presence of toxic gases, unknown atmosphere) • The need for testing the atmosphere (oxygen content, flammability, toxicity) before entry into a sealed tank • Difference between a statement that is always true vs. something that might be true under certain conditions

💭 Think About

• Think about what happens to the air in a space that has been closed and unventilated for a long time. Is it predictable and safe, or uncertain and potentially hazardous? • Which option describes a condition that is guaranteed to be correct every time a tank has been sealed, rather than something that could be true only in some situations? • On real ships, what is the standard safety attitude toward any tank or compartment that has been closed up for a long period?

✅ Before You Answer

• Identify which choice reflects the standard rule for enclosed space entry: assume danger until tested and declared safe. • Eliminate any options that state a specific gas is present without any information about cargoes, residues, or previous use of the tank. • Watch for answers that sound "reassuring" but ignore the need for gas testing and ventilation before entry.