I know what these are intended for, but I bought them to use for various things and NOT their intended use! I use them for mixing and storing meds for the wildlife patients I take care of. I use them for storing small amounts of leftovers. They work well for holding condiments if I'm transporting food. They also work for holding small craft supplies.
You do have to make sure the lid is on tight or they will come off and potentially create a mess. But as long as you make sure that is secure, they work well for my purposes. You just have to put out of your mind what they were designed for!