Microwaving food sometimes reduces its colour and flavour, and does not ‘brown’ it, so food manufacturers have developed a new range of additives to artificially meet consumers’ expectations. These are delivered into the food by little devices glued to the insides of the food containers called ‘susceptors’.

The glues used to fix some early (pre-1992) susceptors released small amounts of the toxic compound bisphenol-A-diglycidyl ether (BADGE) into the food during microwaving. A 1992 study of 52 samples of microwave pizza found that nine of the susceptors used in one brand released BADGE into the pizza when they were cooked in their packaging according to the manufacturer’s instructions.[1] Other research showed that a large number of chemicals were released from susceptors packed with foods such as pizzas, waffles and French fries intended for microwaving. One study identified 44 different volatile chemicals, including the carcinogen benzene.[2] Another toxic chemical found to migrate from packaging into food when microwaved is benzophenone, a component of the ink on the printed paperboard.[3]

Bread and breakfast cereals are often sold in waxed bags for easy heating in a microwave. A recent study showed that microwaving following the instructions on the packaging resulted in 60% of the wax being transferred into the food.[4] The anti-slash PVC plastic films that cover many foods during microwave cooking have been found to release plasticisers into the food to such a degree that a 1996 study recommended that PVC should not be used in direct contact with food during cooking.[5]