Whether it can be heated in a microwave oven depends mainly on the material of disposable lunch boxes. In the disposable lunch box, only No.5 plastic polypropylene (PP) can enter the microwave oven. Polypropylene (PP) is relatively heat-resistant and can withstand the high temperature of about 200℃, so it can be heated by microwave, and repeated heating will not cause any major problems.
Therefore, before putting the takeaway into the microwave oven, be sure to check whether there is a (PP) on the plastic lunch box or whether there is a (5) mark on the triangle arrow. If there is no corresponding logo on the disposable lunch box, it is best to change a container suitable for microwave oven for heating. Of course, even take-out boxes that can be heated by microwave are not recommended to be used again after being heated once.
Microwave heating and the original grease in food will accelerate the removal of some substances that may be harmful to the health in the packaging box. Moreover, the material of the takeaway box is relatively thin and brittle, which is not suitable for repeated use. The heat resistance of other plastics is much worse. It is best not to heat them directly, nor to pack too hot food. Of course, they cannot be used repeatedly.
Precautions for microwave ovens:
Pay attention to the instructions of the microwave oven before using it. Each microwave oven is used in different ways. When heating, you must put in appliances that can be heated. It is best to have tableware marked for microwave heating, such as the sign at the bottom of plastic lunch boxes, some of which cannot withstand high temperatures. In addition, the microwave oven should not contact with any metal, which is easy to damage the microwave oven.
When the heating time is appropriate, the microwave oven heats very quickly and generally does not take long. The food heated in the microwave oven must be given a space to dissipate heat. It is not allowed to use a closed container or the food covered with plastic wrap to make holes in the plastic wrap for exhaust. Don't get too close when using the microwave oven, and don't touch the liner inside the microwave oven at will. The temperature is very high and it will hurt yourself.
When using the microwave oven, don't be close to the wall or electrical appliances, and don't put heavy objects on the microwave oven. The microwave oven is empty, so heating is forbidden.