Which statement about carbon monoxide on board is true?

Which statement about carbon monoxide on board is true?

• A. It has a distinct color.
• B. It can accumulate even if the engine is off.
• C. It is produced only by diesel engines.
• D. It cannot be lethal.

Answer: (B)

Carbon monoxide is a colorless, odorless, poisonous gas that can build up in enclosed spaces aboard a vessel. It can accumulate even after the engine is turned off because leftover exhaust can linger in compartments and, if ventilation is poor, remain at dangerous levels until it’s diluted or vented out. This is why the statement is true. It’s not colored, so it doesn’t have a distinct color. It isn’t produced only by diesel engines—CO comes from incomplete combustion in many types of engines and appliances. And yes, it can be lethal, so the notion that it cannot be deadly is incorrect.

Carbon monoxide is a colorless, odorless, poisonous gas that can build up in enclosed spaces aboard a vessel. It can accumulate even after the engine is turned off because leftover exhaust can linger in compartments and, if ventilation is poor, remain at dangerous levels until it’s diluted or vented out. This is why the statement is true. It’s not colored, so it doesn’t have a distinct color. It isn’t produced only by diesel engines—CO comes from incomplete combustion in many types of engines and appliances. And yes, it can be lethal, so the notion that it cannot be deadly is incorrect.