Do not use any container that is unmarked or has conflicting what?

Using a container that is unmarked or has conflicting information can pose significant safety hazards. It is crucial to have clear, consistent, and specific information about the contents of compressed gas containers to prevent misuse or accidents.

Unmarked containers provide no information about their contents, leading to uncertainty about handling and storage requirements. Conflicting designations, markings, or labels can confuse users regarding the properties, potential hazards, and appropriate procedures related to the gas inside.

Clear markings and labels communicate vital safety information, allowing users to identify the contents accurately and take necessary precautions. Thus, all three aspects—designations, markings, and labels—are critical for safe handling and operation, making “all of the above” the correct answer. It emphasizes the importance of adhering to rigorous safety standards to prevent incidents involving non-flammable compressed gases.