Do not use plastic plates or dishes to heat any fat-containing foods in a microwave oven, even if the containers are marked 'microwave-safe'. There are no agreed standards, and no definitive research has been carried out. The combination of fat, high heat and plastic releases carcinogenic dioxins and other toxins into the food. Researchers found toxic compounds such as methylbenzene, ethylbenzene, 1-octene, xylene, styrene and 1,4-dichlorobenzene in all of the commercial plastic containers they studied.

Other research suggested that the plasticised paper plates and trays often provided with ready-to-cook microwave meals can also leach dioxins into the food.

• The US Food and Drug Administration (FDA) recommends transferring any foods into glass ovenware wherever possible
• Food Science Australia recommends replacing any plastic film (usually only there to reduce splatter) with a sheet of kitchen towel