These are perfect size to carry a small amount of condiments or spices.  Maybe enough salad dressing for a side salad.  The lids fit tight enough that they appear they won't leak.  My plan is to carry my own spices and condiments for use at restaurants which commonly serve a hefty dose of MSG in their dressings and spices. I will try to order something that is least likely to contain MSG...like a unseasoned steak, baked potato, veggies or dry salad.  A bit extreme, but after 2 trips to the hospital with severe swollen face and hives after eating at restaurants, I think I need to be extreme.