5.1 This test method is for evaluating ceramic products that are intended for reheating in a Consumer based microwave oven. It is not intended for evaluating products that will be used in commercial type microwaves.

5.2 This test method is not intended to evaluate metallic or polymeric based products.

5.3 Ceramic products intended for microwave use must also be evaluated for thermal shock resistance and pass the 325 °F criteria as described in Test Method C554, before being tested for microwave safety. This would include specific tests for dinnerware, cookware, drinkware and ancillary items intended for use with hot foods, such as gravy boats or any product intended for microwave use.

5.4 Dishes having a metallic glaze, decoration or paint should not be used in this test or microwave ovens unless it is specifically designed for and marked as microwave safe.

1.1 This test method determines the suitability of ceramicware for use in microwave re-heating applications. Microwave ovens are mainly used for reheating and defrosting frozen foods. Severe thermal conditions can occur while reheating foods. Typical reheating of foods requires one to 5 min in the microwave at the highest power settings. Longer periods than 5 min are considered cooking. Cooking test methods and standards are not addressed in this test method. Most ceramicware is minimally absorbing of the microwave energy and will not heat up significantly. Unfortunately there are some products that absorb microwave energy to a greater extent and can become very hot in the microwave and pose a serious hazard. Additionally, the nature of microwave heating introduces radiation in a non-uniform manner producing temperature differentials in the food being cooked as well as the ceramic container holding it. The differential may become great enough to thermal shock the ware and create dangerous conditions.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.