All cylinders filled with gases other than air must be:

All cylinders filled with gases other than air must be clearly marked to ensure the safety of divers. This marking is crucial because it helps divers and dive professionals quickly identify the type of gas contained within each cylinder. Different gases, such as nitrox, trimix, or other specialty gases, require specific handling and use protocols to avoid accidents or health risks associated with incorrect gas usage.

Proper labeling helps prevent potentially dangerous situations arising from misidentification of gas types, which could lead to complications like oxygen toxicity at depth or running out of breathable gas. It is a standard safety practice in the diving industry to have all cylinders distinctly labeled with their contents to promote safe diving practices and awareness about the potential hazards associated with various gas mixes.