1. glass
Of all materials, glass is relatively the safest. Glass cups are usually made of inorganic silicates, which are fired at a high temperature of more than 600 degrees. Because of their relatively stable chemical composition, they will not produce harmful substances in the firing process. Moreover, the glass surface is smooth and easy to clean, and bacteria and dirt are not easy to breed on the cup wall. Note: the glass is afraid of bursting when it is used for the first time. You should first pour in a little hot water, gently shake the preheated glass, and then pour in hot water for later use.
2. Plastic cups
Many people are worried that plastic cups will cause cancer. In fact, it is relatively safe to choose brands that meet the national quality inspection standards. Generally speaking, the number 1-7 is printed on the bottom of plastic cups. The higher the number, the higher the quality. Common materials are No.5 PP (polypropylene) and No.7 PC (polycarbonate). PP cup has good heat resistance, melting point as high as 167℃ and stable chemical properties. It is the only plastic material that can be put into microwave oven. The cup made of PC can't hold hot water, so it is not suitable for sunlight, because high temperature may release toxic bisphenol A from this material. In addition, although the surface of the plastic cup looks smooth, there are actually many gaps, which are easy to hide evil people and shelter evil people; Moreover, plastic cups can absorb dust and bacteria more easily.
3. Ceramic cups
Beautiful shape and diverse patterns, enamel cups are very popular among young people, with more than one hand.
Ceramic cups are divided into three categories:
① Ceramic cup with colorless glaze inner wall: the main component of ceramic cup is clay, which will form a layer of glaze on the surface of clay after high temperature calcination. In general, this glaze has no harmful substances, so drinking hot water and tea is a good choice.
2 underglaze ceramic cup: This kind of cup is painted first and then calcined at high temperature. At this time, the pigment is stored under the glaze, even if it is brewed with hot water, it will not leak harmful substances, which is relatively healthy and environmentally friendly.
Glazed ceramic cup: This kind of cup is made by first coating pigment on the glaze and then baking and drying. It is easy to exude harmful substances during use, which is harmful to human health and is not recommended. People who like tea like to use teapots. The purple sand teapot is not glazed inside and outside, keeping tiny pores, good air permeability and strong adsorption, which can effectively prevent the loss of tea fragrance. Therefore, teapots and cups are recommended for daily tea drinking.
4. Enamel Cup
An enamel cup is a kind of vessel with enamel inside and outside. Its advantage is that it can prevent the iron and metal inside from rusting, and it is not as easy to break as porcelain, so it takes into account the advantages of metal and porcelain. But in recent years, fewer and fewer people use enamel cups, because the porcelain on its surface is composed of sodium silicate and metal salts, which may contain harmful metal elements such as lead and cadmium. These elements will seep out under acidic conditions or heating conditions, which is easy to harm health. Moreover, the enamel cup is easy to lose porcelain, and the exposed metal core is easy to rust, which is also harmful to human body if it is used continuously. Suggestion: don't use enamel products to contain acidic substances; Broken enamel products should not be used for food and water.
5. Stainless steel cup
Stainless steel cups are corrosion-resistant, wear-resistant and not easy to be damaged. They are widely used as thermos cups and are the first choice for modern people. However, because it is an alloy product, it may contain more heavy metal substances. If used improperly, these substances are easy to seep out or react chemically, which may produce harmful substances.
Tip: Don't use stainless steel cups to hold acidic drinks, such as juice, coffee and carbonated drinks. Don't hold soy sauce, vinegar, vegetable soup, tea, etc. It has been a long time. When cleaning stainless steel cups, do not use strong alkaline or oxidizing chemicals, such as soda and bleaching powder. When buying stainless steel utensils, try to go to a large supermarket with good reputation, and pay attention to whether there are relevant safety signs on the product packaging.
6. disposable cups
Disposable cups is also divided into paper and soft plastic materials. At present, the most widely used paper-plastic cup is a kind of inner polyethylene plastic film, with a layer of paper outside and a layer of coated paper inside, which is relatively safe; Plastic cups used in tea shops and coffee shops are all made of PET. As long as it is not heated at high temperature, harmful substances generally do not leak out and can be used safely.
Summary: The safest thing is: a glass/ceramic cup coated with colorless glaze.
The most unsafe: disposable paper cups, plastic cups and colored ceramic cups.
Note: Do not use stainless steel cups and enamel cups, and drink acidic drinks such as coffee and orange juice.