No. 1 PET polyethylene terephthalate
Common mineral water bottles, carbonated beverage bottles, etc. Heat resistance to 70℃ is easy to deform, and substances harmful to human body are melted out.
No.2 HDPE high density polyethylene
Common white medicine bottles, cleaning products, bath products. Don't use it as a cup, or as a storage container for other items. If the cleaning is not thorough, don't recycle it.
No.3 PVC polyvinyl chloride
Common raincoats, building materials, plastic films, plastic boxes, etc. Excellent plasticity and low price, so it is widely used, and can only resist heat of 865438 0℃. It is easy to produce harmful substances at high temperature and is rarely used in food packaging.
No.4 PE polyethylene
Common cling film, plastic film, etc. Harmful substances will be produced at high temperature, and toxic substances may cause diseases such as breast cancer and birth defects of newborns after entering the human body with food. Don't put plastic wrap in the microwave.
No.5 polypropylene
Common soybean milk bottles, sour milk bottles, fruit juice bottles, microwave lunch boxes. With a melting point as high as 167℃, it is the only plastic box that can be put into a microwave oven and can be reused after careful cleaning.
No.6 polystyrene
Common instant noodle boxes and fast food boxes in bowls. Can't put it in the microwave oven, so as not to release chemicals when the temperature is too high.
No.7 computer other classes
Common kettles, space cups and milk bottles. Department stores often use cups made of this material as gifts. It is easy to release bisphenol A, a toxic substance harmful to human body. Don't heat it when using it, and don't directly bask in the sun.
Extended data
It is best not to use the No.6 cover for hot drinks above 70℃
1. Yesterday, Zhang Jin, a senior three chemistry teacher at Dongguan Guangming Middle School, said that polystyrene is a polymer synthesized by free radical addition polymerization of styrene monomer. When heated to a certain temperature, styrene monomer will be released. In addition, as a plastic product, some auxiliary materials, that is, other chemicals, will be added in the production process. Once it exceeds a certain temperature, the chemicals in it may precipitate, which will affect human health.
2. It is reported that polystyrene is generally safe to use at 0-70℃. However, in many cases, the temperature of hot drinks often exceeds 70 degrees Celsius. At this time, chemical components may precipitate from the cup cover, which will affect human health if used for a long time. Compared with polystyrene, Zhang Jin thinks PP is safer. "Polypropylene is highly crystalline due to its regular structure, so it has a high melting point and good heat resistance.
References:
Baidu encyclopedia-plastic cup
People's Daily Online-Will the lid of No.6 plastic cup be poisoned if it is scalded? Expert: It is best not to use it above 70℃