All cylinders should be considered dangerous because the contents are:

• A. Flammable
• B. Toxic
• C. Corrosive
• D. Pressurized

Answer: (D)

Compressed gas cylinders are dangerous because the contents are stored under very high pressure. That pressure means a small leak, damaged valve, or valve failure can release gas rapidly, turning the cylinder into a dangerous projectile and creating other hazards such as blast effects, frostbite with cryogenic gases, or oxygen displacement in confined spaces. The hazard due to pressure exists regardless of the gas’s other properties, so every cylinder must be treated with care as a potential danger. Even if a gas is nonflammable, non toxic, or not corrosive, the high-pressure release can still cause serious harm, so proper handling, securing, and ventilation are essential.