Text | Popular Science
Noodle soup shops on the street like to use a bowl with black outside and red inside, which looks good and is appetizing.
This kind of bowl is called " imitation porcelain bowl " . It is cheap, resistant to falling, easy to wash, and not easy to deform. It is a kind of tableware with a texture similar to porcelain. It is not fragile and expensive like ceramic bowls, and is different from plastic bowls. The price is the same but it looks more advanced. Many parents like to buy it home and use it as children's tableware.
However, a 1-year-old Guizhou girl suffered from lymphoid leukemia. The cause is speculated to be related to the excessive formaldehyde in the imitation porcelain bowls she usually uses for meals.
In this regard, CCTV conducted an experiment on the safety of melamine bowls and found that most of the melamine bowls on the market exceeded the standard of formaldehyde and melamine and have gradually become "fatal bowls."
CCTV exposed the "fatal bowl" and exposed the dangers of melamine bowls
In order to better distinguish the differences between different porcelain bowls, investigators compared mid-range melamine bowls priced around 10 yuan and low-end melamine bowls priced at 3 yuan, using formaldehyde The detector detects the formaldehyde volatilization data of these two melamine bowls respectively when they are filled with hot water and hot oil.
The results show:
When the mid-range melamine bowl is filled with hot oil and hot water, the formaldehyde data difference is only 0.03 mg;
When the low-end melamine bowl is filled with hot water, the data on the formaldehyde detector is 0.16 mg. After pouring hot oil, the value reached 0.61 mg. The state stipulates that the formaldehyde concentration in the air is ≤0.08. It is about 8 times more than the standard value, and the appearance of the imitation porcelain bowl has also changed.
In addition, the Shanghai Consumer Protection Commission has also conducted corresponding experiments, using 30 pieces of melamine tableware as samples for testing. The results found that 1 pieces contained banned substances, 5 pieces developed cracks after being exposed to high temperatures, and 4 pieces It is extremely easy to be contaminated by .
The Jiangsu Provincial Quality Supervision Bureau also randomly checked the melamine tableware on the market and found that 1/4 of the samples in the batch were unqualified. The brighter the pattern, the more excessive lead migration was detected.
Both formaldehyde and lead can cause harm to the human body, so these imitation porcelain bowls have become "fatal bowls."
What is the difference in material between imitation porcelain bowls and ceramic bowls?
Ceramic bowls need to use three major types of mineral raw materials: clay, quartz and flux. They need to be fired and cooled through complex steps such as mud preparation - shaping - glaze preparation - roasting to form a certain shape. It has the characteristics of light weight, good thermal insulation effect, and good-looking appearance.
Imitation porcelain bowls need to use melamine resin , etc. The standard is A8 or A5.
- A8 refers to the green and environmentally friendly natural mineral powder as the main material, which does not cause any harm to the human body ;
- A5 is 100% melamine resin, non-toxic, tasteless, good temperature resistance, high safety, the temperature is -30℃ ~150℃.
So, it is also called resin bowl or melamine tableware .
Melamine tableware is mainly based on melamine formaldehyde resin , and melamine formaldehyde resin is produced by the polymerization of melamine and formaldehyde under neutral or weakly alkaline conditions.
Although melamine and formaldehyde are slightly toxic and highly toxic substances, the polymer melamine resin formed after the reaction is very stable and will not decompose into these two types of poisons. Even the decomposition temperature needs to reach 200-300℃ , so it is basically non-toxic.
So, why do imitation porcelain bowls on the market detect excessive amounts of melamine and formaldehyde?
Why does the imitation porcelain bowl turn into a poisonous bowl?
The prices of imitation porcelain bowls on the market vary widely. Generally, higher-priced imitation porcelain bowls will have a trademark on the bottom, which displays detailed information such as manufacturer, manufacturing materials, warnings, etc. , and also indicates that the withstand temperature is below zero. Between 20℃ and 120℃, this kind of melamine bowl is a regular melamine bowl.
However, some lower-priced imitation porcelain bowls do not have this information, and even if they do, it is unclear. This type of imitation porcelain bowl usually belongs to inferior quality, also known as counterfeit imitation porcelain bowl, which will release a large amount of Melamine and formaldehyde.
The price of melamine resin is around 15,000 per ton. Some small manufacturers take risks in order to save costs. They mix urea and formaldehyde to make urea formaldehyde resin, which costs only 5,000. It is usually called A1 or A3.
After making the melamine bowl with urea-formaldehyde resin, a layer of melamine powder is applied on the surface. The appearance is no different from the melamine bowl made with melamine resin, but its heat resistance is very poor. , A bowl of hot soup at about 100℃ can release formaldehyde, turning the hot soup into poisonous soup.
Melamine Needless to say, the milk powder incident has always been the hatred of many Chinese babies and parents. The combination of the two can be said to be adding poison to poison. The longer it is used, the greater the harm to the body.
Formaldehyde is clearly included in the list of Class I carcinogens by the World Health Organization . It is colorless and odorless, but long-term exposure can cause chronic respiratory diseases, cell gene mutations, female infertility, fetal malformations, and newborn chromosomal abnormalities. , leukemia , etc.
Therefore, using this low-quality imitation porcelain bowl to eat is equivalent to eating formaldehyde in . Many elderly people do not know the reason and buy it cheaply for their children, which inadvertently harms the baby.
How to distinguish real imitation porcelain bowls from fake imitation porcelain bowls?
- Price:
Generally speaking, the price of a good imitation porcelain bowl is not too low, while the price of a fake imitation porcelain bowl is usually less than 10 yuan , and some can even be bought for 3 yuan. Although
high prices are not necessarily good, 99% of low prices have problems. Everyone should stay clear-headed when buying and don't let the price blur your mind.
- Odor:
When purchasing an imitation porcelain bowl, you can pour hot water above 80℃ to test it. If it emits a pungent smell or smells like urine, it means that it is an inferior imitation porcelain bowl. The formaldehyde and melamine in it are Exceeded.
If there is no pungent smell, it means that this is a qualified melamine bowl.
- tag:
When the imitation porcelain bowl contains both "MF" and "QS" marks, it means that it is made of melamine formaldehyde resin and has passed the quality and safety audit. It is qualified tableware. If there are no these two labels , it means it may be unqualified.
At the same time, melamine bowls are not suitable for storing overheated food, nor are they suitable for holding acidic food, otherwise chemical reactions will easily occur, leading to poisoning.
When purchasing daily necessities, especially imported items such as bowls and pots, it is best to go through formal channels and choose manufacturers with warranty. Do not be greedy for cheap and choose three-no products, which will harm others and yourself.
