The newer Shef reusable stainless steel containers are not microwave and oven safe. As long as your stainless steel container has the etching "DISHWASHER, MICROWAVE, AND OVEN SAFE," you're free to use it in any of those machines. Please remove the lid before heating in the oven.
If your stainless steel container does not indicate that it is "DISHWASHER, MICROWAVE, AND OVEN SAFE," please transfer them to a dish before heating in the microwave and remove the lid before heating in the oven.
