Depending on the necessary holding temperature, you could need a refrigerated container or a heated container, which ever type keeps the food at service temperature.
A coin placed in a plastic container by a grading service.
solids...
Yes, wandering jew plants can root in water if placed in a container.
You will have to define what hazard is posed by the food. Peanuts placed in an airtight container may not be contained well enough for someone with a severe allergy to them, for example (a little peanut oil fingerprint on the outside of the container might be more than enough to trigger an allergic reaction). And I would think radioactive or explosive food would need their own special considerations as well.
Gases, Liquids and solids are sometimes contrasted by the fact that liquids and gasses will take on the shape of the container that they are placed in while solids do not.
A gas fills up the container it is placed in because gases do not have a fixed shape or volume. They expand to fill the available space of the container.
Chemotherapeutic waste is place in a yellow container.
The density of the material is greater than the density of water if it sinks to the bottom of the container when placed in water.
train
To safely transport contact solution on a plane, make sure it is in a container that is 3.4 ounces or less and placed in a clear, quart-sized plastic bag with your other liquids. Keep it in your carry-on bag and inform security during screening.
solid
Solids.