Spill Danger

• Filling a tightly sealed container with hot or liquid food presents a danger of spilling the contents when the lid is opened, with the possibility of burning your hands or staining your clothing.
  
  

Hard to Clean

• When food is filled to the very top of some containers, there is the risk that some of the food will get into hard-to-reach container ridges. Because these areas are also hard to clean, left-behind food particles can make these areas a breeding ground for mold and germs.
  
  

Tough to Seal

• Some types of food storage containers, such as plastic containers, work best when you can push the lid down to "burp" it, creating a partial vacuum seal. Filling liquid food to the top of the container doesn't allow the space for this action.