How poisonous is this "poisonous bowl" that netizens are hotly discussing?

□ Science Times reporter Shi Qi

Recently, the Weibo topic "You may use this kind of poisonous bowl every day" has sparked heated discussions among netizens. The "poisonous bowl" in the topic refers to imitation porcelain tableware.

Substandard products can release harmful substances

According to food science writer Yun Wuxin, imitation porcelain materials are approved by the state for use in tableware, and it is wrong to call them "poisonous bowls". Qualified imitation porcelain tableware needs to use "melamine resin", which is a high molecular compound formed by heat curing melamine and formaldehyde under high temperature conditions. Under normal use conditions, the harmful substances that may be dissolved from melamine resin are very small and are not enough to endanger health.

However, we need to be vigilant. Due to the high price of melamine raw materials, some unscrupulous manufacturers mix urea-formaldehyde resin, which is cheaper, less stable and easy to release formaldehyde, into tableware, which may dissolve more harmful substances and be illegal products. In addition, some small manufacturers may not be able to control parameters such as temperature, pressure and molding time during the production process, resulting in substandard products.

In this regard, Yun Wuxin suggested, "It is difficult for consumers to judge the raw materials used in tableware by themselves, so they need to try to buy them through formal channels to avoid pitfalls."
Do not put in microwave or oven.

Qualified melamine-ceramic tableware should also be used in the correct way. Before use, you can boil white vinegar or water for about 5 minutes, and then let the tableware soak until it cools naturally. On the one hand, it disinfects and sterilizes, and on the other hand, it promotes the dissolution or volatilization of residual harmful substances.

During use, melamine tableware is not suitable for heating in microwave ovens or ovens, nor is it suitable for holding overly hot foods such as hot oil, or acidic beverages such as vinegar, cola, and orange juice. "Because sudden high temperatures and strong acidic conditions will promote the release of harmful substances," said Yun Wuxin.
Ceramic tableware is safer.

Compared with melamine tableware, ceramic tableware is more common in our daily life. Yun Wuxin said that ceramic materials are highly stable and will not dissolve harmful substances, but we need to be careful about ceramic tableware with bright patterns.

According to the different principles of coloring the porcelain blank and the firing temperature, patterned ceramics can be divided into overglaze, inglaze and underglaze products. Overglaze is easy to produce, and the pigments used for coloring have a certain degree of heavy metal dissolution risk, while underglaze and inglaze have stricter process requirements, and the pigments are covered by the formed glaze and will not dissolve heavy metals.

If there is no pattern on the part of the tableware that comes into contact with food, you don't have to worry about the coloring process. But if you choose tableware with patterns on the part that comes into contact with food, it is recommended to choose relatively light colors or products processed by glaze color or underglaze color. When purchasing, you can touch the pattern with your hands. The glaze color and underglaze color are very smooth and will not feel bumpy.