Rockware glass is developing glass jars that can be heated in the microwave for soups and other food products. The glassmaker is working together with Crown Closures Europe to develop a lid that can also be used in the microwave. The use of "heating" labels that use microwave energy and contribute to the heating of the product is also being studied by CCFRA. Market research carried out by Rockware suggest that consumers favour glass as a natural and totally safe packaging medium. Many consumers transfer food products onto plates or dishes before heating in the microwave. Designing a glass jar that would be suitable for this type of use would reassure consumers. Moreover, glass resists temperatures higher than 500 deg C.