Some plastic boxes can be heated by microwave oven. However, it should be noted that the plastic box made of PP needs to be marked with a triangular arrow on the outside, and the number 5 in the box can be used for microwave heating. In addition, special containers made of porcelain, pottery, heat-resistant glass, polypropylene and polyethylene can be used for microwave heating.

Microwave ovens should not use ordinary plastic containers, metal containers or ceramic and closed containers with metal edges. Ordinary plastic containers are easy to deform when heated by microwave oven, releasing toxic substances, polluting food and endangering human health.

Extended data:

Precautions:

1. Choose plastic lunch boxes with good quality and safety labels. High-quality plastic lunch boxes are not easy to pinch and have complete safety labels. Raw materials, date, place of origin and precautions for use are all complete. Inferior plastic lunch boxes are soft to pinch and all kinds of information are incomplete. Pay special attention when buying.

2. Microwave heating requires a special plastic lunch box. When you want to heat the plastic lunch box in the microwave oven, try to use the plastic lunch box dedicated to the microwave oven, and then take a closer look at the maximum tolerance temperature of the lunch box, which will be safer to use. Otherwise, some heat-resistant lunch boxes will release plasticizers when they encounter high temperatures, which will endanger people's health.

3. Clean it before the first use: the plastic lunch box will have some plastic smell when it is used for the first time, so it must be cleaned before use. It is not recommended to use table cleaning, which is easy to leave chemicals and is not good for human health.