4 Working
Material
Paper
Aluminium foil
Cling fi lm
Aluminium trays
Freezer / microwave dishes
Heat-resistant plastic
Unglazed pottery
Glazed pottery
Metal cooking utensils
Normal glass
Pyrex and other ovenproof glass and ceramics
Dishes with metallic decoration
Metallic twist-ties
Mercury thermometer
Sealed pots
Bottle with narrow neck
Roasting bags
How the microwave oven works
A microwave oven is a cooking appliance that uses microwaves to heat food. Microwaves
are electromagnetic waves, just like radio and television waves. A radio converts these
waves into sound, whereas a microwave oven converts them into heat.
The heat arises because the microwaves cause water and fat molecules, that are always
present in food, to move quickly. The molecules slide past each other quickly and friction
occurs. This friction causes heat (try rubbing your hands together quickly).
The microwave oven heats food very intensively, because the microwaves penetrate the
food directly. The waves do not just heat the outside of the food, but get right inside the
food. Compared to conventional methods of cooking, with small quantities, the cooking
time is much shorter.
Permitted
Yes
Yes
Yes
No
Yes
Yes
No
Yes
No
Yes
Yes
No
No
No
No
No
Yes
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