Advice on the use of Cookware
Metal
Do not use metal dishes, tinned food, food wrapped in tin foil and cutlery inside the microwave oven. The metal reflects the microwaves and food is not heated.
The food should be removed from its tin foil containers and placed in dishes that are appropriate for use in the microwave oven. As microwaves don't penetrate tin foil, the food heats only on the surface. By using appropriate dishes, the heat is evenly distributed throughout the food.
EXCEPTIONS:
To cook or defrost pieces of meat of irregular sizes, you may cover the thinner parts with tin foil, which should be kept at least 2 cm away from the oven walls, otherwise these may cause an electric arc.
Metal spits may be used as long as they are smaller than the pieces of meat.
Glass
All heat proof glass containers may be used.
Crystal contains a percentage of lead, which may cause it to crack if used in the microwave oven. The same may happen to glass dishes with jagged edges.
Porcelain
Porcelain dishes may be used but they should not have hollow handles. Humidity may be formed inside the hollow handles, which will causes an increase in pressure that may cause them to break.