If, in a compartment or space, the gas or oxygen content is not within permissible concentration, and dangerous gases are either present, or may be produced by residues, what would be the safety designation listed on a marine chemist's certificate?

Correct Answer: Option D — Not Safe for Men - Not Safe for Fire

If gas or oxygen levels fail to meet safety standards, or if residues present a risk of generating dangerous gases, the space is deemed hazardous. The Marine Chemist will designate it as 'Not Safe for Men' and 'Not Safe for Fire' to prevent injury or catastrophic ignition during operations.