1, first of all look at the appearance of the plastic bag is a "food use" sign. Usually this sign should be in the front of the bag, more prominent position. The second is to look at the color. Generally speaking, colored plastic bags mostly use recycled plastic materials that cannot be used to hold food. For example, black plastic bags used in some food markets to hold fish, shrimp, and other aquatic products or meat were originally used to store rubbish, and consumers should avoid using it. Finally, look at the plastic bag for impurities. Put the plastic bag in the sun or light to see if there are black spots or not. Plastic bags with impurities must be used as raw materials.
2. Whether there is any odor in the plastic bags or whether they are disgusting Qualified plastic bags should be odor-free, and unqualified plastic bags with various additives due to the use of additives.
3, qualified plastic bags have a certain strength, will not be a tear to break; unqualified plastic bags due to the addition of impurities, often very poor strength, easy to break.
4. When a qualified plastic bag is shaken, it will emit a crisp sound; unqualified plastic bags are often “squeaky”.
5. Put the plastic bag in the water and press it by hand to the bottom of the water. Wait for a while. The surface of the bag is a non-toxic plastic bag. It is a toxic plastic bag that sinks under the water.
6, touch the surface of the plastic bag, it is smooth and non-toxic. If the colors are mixed, they are sticky and astringent and are toxic.
7, burning: The plastic bag cut off a corner, on the fire and a burning, non-toxic burning, burning, it will continue to burn after leaving the fire, and the emergence of yellow flame, and the melted like a candle drop by drop , issued a paraffin odor; toxic, non-flammable, green flame after burning, and there is a smell of smelly nose.
Plastic bags have less heat and oil food. Of course, if you can't determine if the plastic bag is safe, avoid using it for overheating or fatty foods. This is one of the ways to reduce the damage. Expert Lu Sihao said that unsafe plastic bags contain mainly harmful substances such as dyes and heavy metals. The oils contained in oily foods such as meat, fish, and fritters are actually a kind of solvent, which can cause the harmful substances in the plastic bags to precipitate; and high temperatures can soften the plastics, and can also promote the precipitation of harmful substances and cause poisoning. Therefore, it will be relatively safe to use normal temperature vegetables or frozen foods. Of course, we must try our best not to use plastic bags to hold food. You can bring a basket or cloth bag when you are buying food. When you are forced to use it, you should remove the food from the plastic bag as soon as you go home.