I can't attest to whether it is leak proof or not. It is not a silicon bag, but a sewn fabric bag.I haven't put liquid in it, and I don't intend to.The bag is very nice.I purchased it to put in regular rotation for my daughter's packed lunch.It has such a beautiful design that immediately gathered comments and compliments on its first use. The three bag sizes are perfect for packing snacks, with the largest bag capable of holding a sandwich with plenty of room to spare.Cleaning was simple: I used soap and water on the inside and inverted the bag to allow it to air dry.I intend to minimize my consumption of single use plastics, and the fabric is very stiff and feels like I will be able to use it multiple times.
