What are the hazards of plastics when exposed to high temperatures

In ancient times, people used copper or ceramic products. Later, iron products gradually appeared, making people's lives more convenient. Until later, plastic products gradually became the mainstream in various industries and families. However, everyone knows that plastic is not resistant to high temperatures. At high temperatures, plastic will melt and release unpleasant gases. So, what are the hazards of plastic when exposed to high temperatures?

PET No. 1:

Do not recycle mineral water bottles and carbonated beverage bottles to hold hot water. Use: Heat-resistant up to 70°C, only suitable for warm or cold drinks. If filled with high-temperature liquids or heated, they will easily deform and may melt out substances that are harmful to the human body. In addition, scientists have found that No. 1 plastic may release the carcinogen DEHP after 10 months of use.

“No. 2” HDPE:

It is recommended not to recycle cleaning supplies and bath products if they are not cleaned thoroughly. Use: They can be reused after careful cleaning, but these containers are usually difficult to clean, and the original cleaning supplies will remain, becoming a breeding ground for bacteria, so it is best not to recycle them.

PVC No. 3:

It is rarely used in food packaging and it is best not to buy it. This material is prone to produce harmful substances at high temperatures, and it will even be released during the manufacturing process. After the toxic substances enter the human body with food, they may cause breast cancer, congenital defects in newborns and other diseases. At present, containers made of this material are rarely used to package food. If in use, never expose it to heat.

"No. 4" LDPE:

Do not wrap food with cling film, plastic film or other preservative films before putting it into the microwave. Usage: It is not heat-resistant. Usually, qualified PE cling film will melt when the temperature exceeds 110°C, leaving some plastic preparations that cannot be decomposed by the human body. In addition, when wrapping food in plastic wrap and heating it, the fat in the food can easily dissolve the harmful substances in the plastic wrap. Therefore, before putting food into the microwave, you must first remove the plastic wrap.

PP No. 5:

When placing the microwaveable lunch box in the microwave, remove the lid. Use: The only plastic container that is microwave safe and can be reused after careful cleaning. It should be noted that some microwave lunch boxes are indeed made of No. 5 PP for the box body, but the box lid is made of No. 1 PE. Since PE cannot withstand high temperatures, it cannot be placed in the microwave together with the box body. To be on the safe side, remove the lid before placing the container in the microwave.

PS No. 6:

Do not use a microwave to cook instant noodles in bowls or fast food boxes. Usage: It is heat-resistant and cold-resistant, but it cannot be placed in a microwave oven to avoid the release of chemicals due to excessive temperature. It should not be used to transport strong acids (such as orange juice) or strong alkaline substances, because they will decompose polystyrene, which is harmful to the human body and can cause cancer. Therefore, you should try to avoid packing hot food in fast food containers.

Other categories of PC No. 7:

The PC glue in kettles, cups and baby bottles releases bisphenol A when exposed to heat. Use: A widely used material, especially in baby bottles, which is controversial because it contains bisphenol A. Lin Hanhua, associate professor of the Department of Biology and Chemistry at City University of Hong Kong, said that in theory, as long as bisphenol A is 100% converted into plastic structure during the production of PC, it means that the product does not contain any bisphenol A at all, let alone release. However, if a small amount of BPA is not converted into the plastic structure of PC, it may be released and enter food or drinks.