Food-grade plastics are divided into: PET (polyethylene terephthalate), HDPE (high density polyethylene), LDPE (low density polyethylene), PP (polypropylene), PS (polystyrene), PC and other categories

PET (polyethylene terephthalate)

Common uses: mineral water bottles, carbonated beverage bottles, etc.
Mineral water bottles and carbonated beverage bottles are made of this material. Drink bottles cannot be recycled for hot water, and this material is heat resistant up to 70°C. It is only suitable for warm or frozen drinks, and is easily deformed when filled with high-temperature liquids or heated, with substances harmful to humans leaching out. Moreover, scientists have found that after 10 months of use, this plastic product may release carcinogens that are toxic to humans.

For this reason, drink bottles should be discarded when they are finished and not used as cups or storage containers for other items to avoid health problems.
PET was first used as a synthetic fibre, as well as in film and tape, and only in 1976 was it used in beverage bottles. PET was used as a filler in what is commonly known as the ‘PET bottle’.

The PET bottle has excellent hardness and toughness, is light (only 1/9 to 1/15 of the weight of a glass bottle), easy to carry and use, consumes less energy in production, and is impermeable, non-volatile and resistant to acids and alkalis.

In recent years, it has become an important filling container for carbonated beverages, tea, fruit juice, packaged drinking water, wine and soy sauce, etc. In addition, cleaning agents, shampoos, food oils, condiments, sweet foods, drugs, cosmetics, and alcoholic beverages have been used in large numbers in packaging bottles.

HDPE (High Density Polyethylene)

Common uses: cleaning products, bath products, etc.
Plastic containers for cleaning products, bath products, plastic bags used in supermarkets and shopping malls are mostly made of this material, can withstand 110 ℃ high temperature, marked with food plastic bags can be used to hold food. Plastic containers for cleaning products and bathing products can be reused after careful cleaning, but these containers are usually not well cleaned, leaving residues of the original cleaning products, turning them into a breeding ground for bacteria and incomplete cleaning, so it is best not to recycle them.
PE is the most widely used plastic in industry and life, and is generally divided into two types: high-density polyethylene (HDPE) and low-density polyethylene (LDPE). HDPE has a higher melting point than LDPE, is harder and more resistant to the erosion of corrosive liquids.

LDPE is ubiquitous in modern life, but not because of the containers it is made of, but because of the plastic bags you can see everywhere. Most of the plastic bags and films are made of LDPE.

LDPE (Low Density Polyethylene)

Common uses: cling film, etc.
Cling film, plastic film, etc. are all made of this material. Heat resistance is not strong, usually, qualified PE cling film in the temperature of more than 110 ℃ will appear hot melt phenomenon, will leave some human body can not decompose the plastic agent. Also, when food is heated in cling film, the grease in the food can easily dissolve the harmful substances in the film. Therefore, it is important to remove the plastic wrap from the food in the microwave first.

PP (polypropylene)

Common uses: microwave lunch boxes
Microwave lunch boxes are made of this material, which is resistant to 130°C and has poor transparency. This is the only plastic box that can be put into the microwave and can be reused after careful cleaning.

It is important to note that some microwave containers are made of PP 05, but the lid is made of PS 06, which has good transparency but is not resistant to high temperatures, so it cannot be placed in the microwave together with the container. To be on the safe side, remove the lid before placing the container in the microwave.
PP and PE can be said to be two brothers, but some physical and mechanical properties are better than PE, so bottle makers often use PE to make the body of the bottle, and use PP with greater hardness and strength to make the cap and handle.

PP has a high melting point of 167°C and is heat resistant, and its products can be steam sterilised. The most common bottles made from PP are soy milk and rice milk bottles, as well as bottles for 100% pure fruit juice, yoghurt, juice drinks, dairy products (such as pudding), etc. Larger containers, such as buckets, bins, laundry sinks, baskets, baskets, etc., are mostly made from PP.

PS (polystyrene)

Common uses: bowls of noodle boxes, fast food boxes
The material used to make bowls of noodles and foam fast food boxes. It is heat and cold resistant, but cannot be placed in a microwave oven to avoid the release of chemicals due to high temperatures. It should not be used for strong acids (e.g. orange juice) or alkaline substances, as polystyrene, which is bad for humans, can be decomposed. Therefore, you should avoid packing hot food in fast food containers as much as possible.
PS has low water absorption and is dimensionally stable, so it can be injection moulded, pressed, extruded or thermoformed. It can be injection moulded, press moulded, extruded and thermoformed. It is generally classified as foamed or unfoamed according to whether it has undergone the “foaming” process.

PC and others

Common uses: water bottles, mugs, milk bottles
PC is a widely used material, especially in the manufacture of milk bottles and space cups, and is controversial because it contains Bisphenol A. Experts point out that in theory, as long as BPA is 100% transformed into the plastic structure during the production of PC, it means that the product is completely BPA-free, not to mention that it is not released. However, if a small amount of BPA is not converted into the plastic structure of PC, it may be released into food or beverages. Therefore, extra care should be taken when using these plastic containers.
The higher the temperature of PC, the more BPA is released and the faster it is released. Therefore, hot water should not be served in PC water bottles. If your kettle is number 07, the following can reduce the risk: Do not heat it when in use and do not expose it to direct sunlight. Do not wash the kettle in the dishwasher or dishwasher.

Before using it for the first time, wash it with baking soda and warm water and dry it naturally at room temperature. It is advisable to stop using the container if it has any drops or breaks, as plastic products can easily harbour bacteria if they have a finely pitted surface. Avoid repeated use of plastic utensils that have deteriorated.