Why is it a bad idea to freeze water in a plastic container?

Answer 1

If you try to freeze water, juice or other liquids in a closed plastic container without leaving room for expansion, your container will crack or burst. I fill plastic bottles or jugs with liquid, leaving plenty of room at the top for expansion. Once the liquid is frozen, then you can safely tighten the lid and then when you want to take it off use warm water to wash it then take it off.

The reason why it's a bad idea to freeze water in a sealed plastic container is because the container can break. I would say if the water bottle is full and you freeze it then burst open and then it will be an even bigger mess then if you just started with a half full bottle. Which works just as well.

Leave at least a 1/4 of the plastic without water because water expands.

Other notes:

Jugs of ice keep the freezer from having to work as hard to cool the compartment, assuming you don't keep your freezer space full of food. In the event of a power outage the chunks of ice can help prevent the loss of your food for a little longer. It is NOT indefinite, but it does help for brief periods of time. My freezer lasted two days during a summer hurricane.

There is a myth going around that freezing water in a plastic container causes the plastic to release dioxin, and thereby causes breast cancer. This is not true.