DETERMINATION OF VOLATILE CHEMICALS RELEASED FROM MICROWAVE-HEAT-SUSCEPTOR FOOD-PACKAGING

Microwave heat susceptors that convert electromagnetic energy to heat attain high temperatures that make it possible to cook some foods to g olden crispness in a microwave oven. Susceptors are typically packaged with foods intended for microwave use, e.g., waffles, pizzas, and fre nch fries. The high temperatures >302-degrees-F used to cook some food s release trace levels of volatile chemicals from metalized polyester film, adhesive, and paper packaging materials; these volatile chemical s may be absorbed by the food. We simulated microwave susceptor cookin g conditions and developed protocols by using headspace concentration capillary gas chromatography and mass spectrometry to identify volatil e chemicals released from heated susceptors. We purchased a limited, c ross-sectional sample of local retail microwave food products packaged with susceptors and used our protocol to analyze 10 different suscept or products. Although more than 140 unique chromatographic peaks were tabulated, only 44 volatile chemicals were identified, including 1,1,1 -trichloroethane, benzene, and 2-(2-butoxyethoxy)ethanol, which were d erived primarily from the paper and adhesive susceptor components. No one susceptor contained all the identified substances. The standard ad ditions technique was the preferred method for quantitation. Trichloro ethane and 2-(2-butoxyethoxy)ethanol were present in several products at 75-122 mug/in.2 of susceptor surface area. Benzene was found in 3 s usceptors at less-than-or-equal-to 0.22 mug/in.2 levels. Examination i ndicates that adhesives used in more recent susceptor products were re formulated to remove even this trace level of benzene.