What's the harm of packing food in plastic bags?

Packaging food in plastic bags is convenient and hygienic, so it is more popular with people. Plastic bags are made of plastic film, and the raw materials of plastic film are PVC and polyethylene. At present, PVC plastic film and polyethylene plastic film are commonly used.

PVC plastic film is the earliest one on the market. Because toxic substances such as aluminum are added in the process of adding plasticizers, stabilizers, lubricants and colorants, food packaged in plastic bags made of PVC films will pollute food. People often eat contaminated food, which will make toxins accumulate in the body and affect their health, so it is not appropriate to pack food in this plastic bag.

Polyethylene plastic film has high chemical stability and low biological activity. After teratogenic test and carcinogenic test, it has no toxic effect. This is a relatively safe plastic film, which can be used to package food. But it also has some disadvantages: poor light resistance, easy aging and fragile; If you pack overheated food, plastic bags will leak; Oily foods will take away grease; The stuffing cake will dehydrate and harden; Sugar will lose water and agglomerate after packaging, or absorb moisture and melt, and so on. Therefore, when packaging food that needs to be stored for a period of time, double-layer polyethylene plastic film or double-layer polyethylene plastic film bag should be used.

PVC film plastic bags can't hold food, but polyethylene film plastic bags can hold food. How to distinguish these two kinds of plastic bags?

PVC plastic bags are sticky to the touch and not easy to burn. Put it out immediately after leaving the fire, and the flame is green.

Polyethylene plastic bags feel lubricated by hand and the surface looks like a layer of wax. They are flammable in case of fire, and their flames are yellow. When burning, they drop like candles and tears, and have a paraffin smell.