Which action is prohibited when handling cylinders?

When handling cylinders, suspending them in an uncontrolled manner is prohibited due to safety concerns. Cylinders can be heavy and pressurized, and if they are not secured properly when suspended, they may fall or tip over. This can lead to serious injuries or accidents, including leaks of hazardous materials stored within the cylinders, which can pose risks not only to the handler but also to nearby individuals and the environment.

On the other hand, transporting, storing, and inspecting cylinders are essential practices necessary for safe operation. Proper transport involves using suitable equipment and techniques to ensure that cylinders remain secure and upright. Storage requires following regulations that dictate how and where cylinders should be stored to minimize risks, such as maintaining them in an upright position and away from heat sources. Inspecting cylinders is crucial for identifying any potential issues, such as leaks or damage, ensuring they are safe for use. Thus, suspending cylinders is the only action among the options listed that presents an inherent risk when not performed according to safety guidelines.