Italiano, where did you copy and paste that from? That looks like its from a FAQ section on a product to beat drug tests in one manner or another and not human urine. The decay or human urine is slowed by freezing and i'm not sure an airtight container makes a difference.

Windigo, you really think that toilet water compares to the cold environment provided by a refrigerator? The temp inside most refrigerators is about 38-45. What do you think the temp is of that toilet water?

Why are your parents testing you?