A biohazard warning label must be attached to all of the following EXCEPT:

A biohazard warning label is essential for identifying materials that may pose a risk to human health due to their infectious or hazardous nature. Blood products, such as a unit of blood released for clinical use, are handled according to specific regulations and guidelines, especially in clinical settings where they have been tested and deemed safe before release. This unit of blood is generally not labeled with a biohazard warning because it is used for therapeutic purposes and does not present a biohazard risk to patients or healthcare providers in normal circumstances.

In contrast, radioactive waste containers, biohazardous materials, and infectious agents are considered hazards that require clear labeling to ensure the safety of those who might come into contact with them. Proper labeling helps maintain safety protocols, informs personnel about the risks involved, and dictates the necessary precautions for handling such materials. Therefore, while the other categories require biohazard labeling to inform of the inherent dangers, blood units released for clinical use, being regulated and screened, do not.