While using plastic container, we had better have a look at the number beneath the bottle, only when we know about the material property can we use properly. 
 


 



There is a triangle shaped by three arrows and a number is inside the circle ranging from one to seven. For example, under number one signs PET, it is usually applied to carbonated beverage bottles. When heated to seventy degree centigrade, its shape easily gets changed and gives off harmful substances.  
 
Recently an article named Knowing Toxicity from Bottle Bottom; Ignorance Causes Death is very popular o the internet. This article introduces the meaning of bottle bottom numbers and describes using taboos of bottles numbered from one to seven. 
 
After reading this article, Mr. Liu is quite worried. In shops near his house, soy sauce, vinegar, oil and other condiment are all packaged in stained plastic bottles. He has noticed the numbers under bottle, but he thought they stand for safety level.  

Chinese plastic association recycling committee secretary-general Mr. Wang introduces that repeated use of plastic bottles is nor that horrible. Arrowed triangle means that this bottle can be recycled. The numbers only represent its main materials and it doesn’t mean whether it’s safe or not.

Number one recyclable PET bottle can contain normal temperature water but not for hot water or PH beverages.

Number two bottle is made from HDPE; they are usually not suitable to make water bottles and are not recyclable.
 
Number five is polypropylene/PP and is recyclable, usually used in microwave tableware.
 
Number sox is made from polystyrene/PS, chemical substance will be given off after high temperature heating.

Consumers should avoid repeatedly using old plastic containers, and had better not repeatedly use beverage bottles.

The best storage container is traditional Chinese pottery and canopy jars.