These containers are safe for use in microwave, freezer and dishwasher. These are food-safe and are mostly used for food items in restaurants, take-away, delis or even for domestic purposes. You can, however, use them for any items that you want to store, display or takeaway. Simply fill the container and close the lid. The snap-close lids help make these containers leak proof. These containers are light-weight and stackable so don't take much space to store.