My step-grandmother retired from Corning, but before she did, she gave me a set of 4 French White baking dishes w/lids. They can be safely used in excess of 1,000 degrees, but since most ovens only go to 500 or 550 at most, I think you are safe. Just don't use them on a stove top burner. Uneven heating or cooling is what might crack ceramicware.