Final answer:
The correct action when there is doubt about the sterility of contrast media is to discard it to ensure patient safety and adherence to biosafety guidelines.
Step-by-step explanation:
When there is a doubt regarding the sterility of the contrast media, the appropriate action to take is to discard the media. In medical imaging, patient safety is the highest priority, and using non-sterile contrast media can lead to serious infections and complications. Considering biosafety practices and procedures, it is not safe to shake, dilate, or heat the contrast media in an attempt to sterilize it. Once sterility is compromised, the only safe course of action is to dispose of the contrast media properly, ensuring it is done in accordance with biomedical waste regulations.