1, toxic substances will be released after heating at high temperature. In order to increase its viscosity, transparency and elasticity, a certain amount of plasticizer is added to the PVC preservative film, and the plasticizer contains a compound agent, which has a great destructive effect on the endocrine system of human body and will disturb the hormone metabolism of human body. After being wrapped for a long time, the grease in the food can easily dissolve the harmful substances in the fresh-keeping bag, and when heated, it will accelerate the release of the combined chemicals in the plasticizer into the food, which will cause women to suffer from breast cancer, birth defects of newborns, decreased sperm count of men, and even mental illness after eating. At present, the use of plasticizers has been restricted in Europe and banned in Korea.

2. At present, there are three kinds of plastic wrap on the market. One kind is PVC plastic wrap. Although it can be used for food preservation, it can't be heated in the microwave oven or used for packaging oily foods because it may contain benzene ring plasticizers, otherwise the compounds will be harmful to human health. One kind is PE plastic wrap, which is widely used in the market because of its high safety without adding plasticizer; There is also a kind of PVDC preservative film, which is not widely used and sold because of the high production cost, and is only used for the preservation of some high-priced products.

3. It is understood that the new national standard "Plastic Self-adhesive cling film for food" was officially implemented on February/February/2009, which stipulated that PVC cling film should be marked with warnings such as "Do not touch greasy food", "Do not heat in microwave oven" and "Do not use at high temperature". The plastic wrap that can be heated by microwave oven should be marked with the words "can be used by microwave oven", and the heating method and the highest temperature resistance should be clearly indicated. If you can use glass ceramics to heat food in a microwave oven, don't use plastic. If it is convenient to carry, you should also buy qualified microwave plastic lunch boxes or films. Pay attention to whether PE or PVDC is marked on the package. If not, don't buy it.