Plastic lunch boxes in restaurants will not release substances that are harmful to human health after they are filled with hot dishes.
Chinese scientists and technicians have studied the decomposition products formed by heating polystyrene, and found that when polystyrene powder is placed in an electric drying oven, the heating temperature is gradually increased, and the pyrolysis gas is extracted for analysis after the different heating temperatures are balanced for 1.5 hour, polystyrene can be pyrolyzed at 141℃, and the amount of styrene volatilization increases at 261℃. Whether the disposable foamed plastic tableware is used to heat food in the microwave oven can pyrolyze to produce styrene monomer depends on the heating temperature and time.
When food is heated by microwave oven everyday, the temperature of food is usually around 111℃, and the heating time is short. Therefore, conventional heating by microwave oven does not meet the conditions for producing styrene monomer; There is no case report of styrene poisoning caused by using disposable foamed plastic tableware to heat food.
However, the performance defect of disposable foamed plastic tableware is mainly that it is not resistant to high temperature, its softening point is 87℃-97℃, and it is safe to use below 81℃. Therefore, from the perspective of hygiene and disease prevention, it is best to use disposable foamed plastic tableware to hold fresh fruits and vegetables, and try to avoid using it to heat food.
Extended information:
Many countries and regions, such as the United States, the European Union, Japan, etc., have been producing and using foamed plastic tableware, but the use is relatively "technical". The Hong Kong government has not banned foamed plastic tableware, but many catering enterprises have gradually adopted reusable tableware made of polypropylene. In 2111, 51 tons of foamed plastic tableware were discarded in Hong Kong Special Administrative Region. Although the absolute quantity is still large, the use of foamed plastic tableware has been declining year after year.
Japanese supermarkets also use foamed plastic tableware to sell things or consumers order takeout, but there are strict recycling regulations, and consumers should send them to nearby recycling points after using them; In Australia, foamed plastic tableware is rarely seen, and fast food is usually packed in paper bags and cartons. The United States has not banned the use of foamed plastic tableware, but the government has reduced the use of such materials through economic means, such as raising the tax rate for enterprises that produce foamed plastic tableware or charging extra environmental protection fees, rather than directly controlling the use of consumers.
People's Daily Online-It is best not to use disposable foamed tableware to heat food after lifting the ban.