The current tableware market is mixed, the good and the bad are intermingled, there are so many ceramic tableware on the market, how do we judge whether it is food-grade safety?
The quality of ceramic tableware, in addition to beautiful appearance and strong applicability, the most important thing is good physical properties and high safety performance.
Physical properties generally refer to resistance to dishwashers, microwave ovens, knives and forks, product strength, etc.
Safety includes the performance of heavy metal precipitation, thermal stability and other hidden dangers.
Thermal stability, generally refers to the tableware heated to a certain temperature, and then placed in 20 degrees normal temperature water to observe whether there are cracks in the tableware.
The most common risk of thermal stability is the pouring of hot water into a cup or the cracking of bowls and bowls.
The most common problem of heavy metal precipitation is lead and cadmium pollution. In fact, there are other metal pollution problems, such as cobalt, barium and so on.
It is better to pay attention to the safety of the following types of products when choosing tableware:
1.High temperature white porcelain products.
Usually refers to the glaze firing temperature above 1350 degrees high-temperature white porcelain hard porcelain.
This kind of product generally has high whiteness (not the surface glaze color, but the color of the porcelain body of the product, mainly looking at the non-glazed parts such as the foot), and the percussion sound is clear.
But there are also a lot of relatively low temperature white porcelain, and even stoneware (ceramic products between pottery and porcelain), the sound will be relatively crisp.
Generally speaking, there is no problem with the white body or color glaze of high-temperature white porcelain, but the high-temperature white porcelain with decoration also has certain risks, so please choose carefully.
2.in-glaze or under-glaze decoration products.
Usually, the identification method is to have the feel of the above-glaze decoration, but some of the above-glaze decoration can be done very well, just like in the glaze, especially the bone porcelain products (most of the bone porcelain decoration products are on the glaze).
In fact, it can be carefully observed that the color of the glaze will generally dissolve into the deeper glaze, and the glaze will only be on the surface of the glaze.
The contact surface between in-glaze or under-glaze products and food is the glaze layer itself, so there is no problem with the surface glaze layer, and there is generally no problem with the product.
The firing temperature of above-glaze decoration is much lower than that of glaze, and it can not be completely melted into the glaze, which is a major source of heavy metal pollution of ceramic products.
Many glaze decoration products are also safe, but the relative risk is relatively high. Over the years, there have been heavy metal problems in glaze products from small factories to top brands, and most of them may have been displaced to various markets.
How to avoid the harm to people caused by the dissolution of heavy metals from ceramic tableware.
- Choose and buy ceramic tableware, the first choice is underglaze color, the inner wall of tableware should not have too many bright color painting, large area pattern ceramic tableware.
- Never use ceramic tableware with flowers inside to eat over-sour and salty food.
- Ceramic tableware that has been placed for too long should be cleaned and wiped with hot water before use.
- After using household ceramic tableware for a period of time, discoloration or pigments that can be scraped off are found. This should be paid attention to, and it is recommended that it should not be used again.
- painting gold porcelain, it is recommended not to buy food, painting gold is a glaze color process, generally after 700-800 degrees low temperature baking, does not mean that gold painting tableware is unsafe, if you can bake a higher temperature, and the use of regular food-grade Jinshui is OK.
- The ceramic tableware bought back should be soaked and boiled in 4% vinegar water, which can remove most of the toxic substances and greatly reduce the harm of harmful substances spilled from the surface of ceramic tableware to the human body.