Treo By Milton Hi Borosilicate Clip Fresh Round Glass Container are made of High Borosilicate glass which makes it safe for use in microwave ovens freezers and refrigerators. Freedom to carry liquid dishes as these containers are leak proof. Glass containers are 100% food safe; it doesn't leach potentially harmful chemical unlike the other materials and are 100% BPA free. Due to its non-porous nature it doesn't absorb food & food smell stains or germs making them very easy to clean. The best part is that it retains crystal clarity even after repeated use and Safe to use in freezers & refrigerators. This glass container is versatile can be used as a meal preparation container lunch box for adults and kids variety of occasions and events baking dishes in the microwave/oven leftovers picnic storing food in the freezer for later use and as a glass storage container for organizing various food items. For any queries kindly reach customer care number as mentioned on the product packaging along with the proof of purchase.