Food Containers help you by packaging leftovers in sturdy, reusable containers that stack neatly in your freezer and lunch bag. With our innovative 4-hinge snap-lock system, you can confidently send last night's lasagna to work or school, saving money on fast food trips and processed lunch kits. • Containers aren't just cost conscious; they're healthier, too. Safe, durable and reliable Food Containers are made from food safe polypropylene. They can be placed in your refrigerator, freezer, microwave. The vent can keep the food fresh and humidity for a long time, if it is dry food, you can close the vent.