Stainless steel reusable and microwave safe food containers
Most stainless steel food containers are made of 304 grade (18/8 stainless), and new microwave-safe containers have had their corners specially designed so they do not cause problems when used in a microwave oven. The safe use of these products is now guaranteed by many research organizations. Microwave-safe stainless steel food containers are now being sold in Asia, the United States, and Europe.
worldstainless has published a leaflet with more information. It can be downloaded here.