"Can this plastic box be heated in the microwave?" Ms. Lee, who bought the microwave lunch box in the supermarket, picked up a plastic lunch box without any notices and instructions to ask the sales staff. She got the reply: "No problem, many people are buying this home for use in the microwave oven."
And this "no problem" has just bought a similar microwave oven Wang Qun into a "problem", Aunt Wang smell the smell when you turn on the microwave and saw the plastic lunch box has changed shape.
With the accelerating pace of urban life, fast heating, easy to use microwave oven has become an indispensable item in people's lives. But have you ever noticed around a variety of microwave meal boxes? "Plastic disposable tableware General technical requirements" has been implemented since December last year, but after a lapse of six months, not according to this standard plastic lunch boxes, ceramic products are still everywhere in the market.
Different styles of identification unclear
"The specific is not clear, it should be sealed plastic box can be put into it," "our family only sealed with a well-known brands, other brands do not know can not be used," "crisper will be able to use it, "There should not be a big problem with choosing a special label for a microwave oven." ... In the face of all kinds of meal boxes and materials on the market, consumers are somewhat "confused."
"As long as it is a good quality plastic box can be used." Dazhong Electronics sales counters microwave sales staff said: "nor is it necessary to mark microwave oven dedicated lunch box to use." When a reporter asked how to determine the plastic lunch box Quality is good or bad, the answer given by sales staff is "with the feeling."
With the feeling can determine what kind of plastic lunch box can be used in the microwave? Reporters visited several major supermarkets learned that some of the supermarket plastic lunch boxes and plastic cups are messily piled up in the supermarket cart to engage in promotional activities, there is no way to identify the quality of good or bad. There are also some supermarkets directly to the plastic gift boxes and other products bundled sales. According to sales staff, such lunch boxes can be used for microwave ovens. Reporter found that, although the vast majority of the sales of microwave lunch boxes, marked above, "microwave oven," the words, but no other instructions.
Not only plastic lunch boxes, the reporter also found that there are ceramic products this problem. Sales staff said that as long as the standard microwave oven can be used, but the price is more expensive to use more assured.
Only marked "microwave oven", "microwave security" words really apply, safe yet? It is well-known that microwave oven lunch boxes require a temperature range when heated, but most of them do not have any description of the applicable temperature range, either for plastic lunch boxes or for ceramic products. To be truly safe to use.
Dedicated not specific differences
It is understood that currently widely used in microwave oven food containers are ceramic and plastic two categories, and now the domestic market for the sale of such containers, regardless of almost all ceramic or plastic labeled "microwave oven" message. In fact the microwave performance and quality of these products vary greatly. According to Beijing University of Technology School of Materials Science and Engineering introduced Yang Ru to ceramics, for example, for microwave heating ceramic food containers should have higher requirements than the national standard. Because the main raw material for ceramics is the clay (kaolin) whose chemical composition is aluminosilicate. High-quality kaolin sintered at high temperature stable performance, non-toxic, low dielectric loss of microwave, microwave oven is the ideal receiver. The inferior kaolin is mixed with a variety of metal impurities. Some companies in order to reduce costs and processing convenience, mixed with iron, lead, cadmium and other compounds, such containers will increase the microwave loss, easy to heat up. When heated in a microwave oven, these metals can precipitate in small amounts, endangering health or causing chronic poisoning. The glaze on porcelain, containing lead, mercury, cadmium, tin and other oxides, heating is more a killer of health.
For plastic containers, experts believe that from polyethylene (PE) Thermoplastic into the container in the range of -20 ℃ ~ 120 ℃ chemical stability, low microwave loss, non-toxic, is the ideal choice for microwave oven. Polypropylene (PP) made containers (including film), microwave loss slightly larger than polyethylene, is also a better microwave oven. PP plastic products can work long hours at 100 ℃, in the absence of external force, PP products are heated to 150 ℃ will not be deformed. As regards PVC, polyester and polycarbonate (PC), foam boxes, poor cling film, disposable lunch boxes and all kinds of recycled plastics, even inferior containers made of waste materials should be strongly forbidden Microwave oven.
More to note is that due to the actual process of making polycarbonate (PC), a small part of the raw material bisphenol A is not fully converted into plastic, heat will be released into the food, will be developing fetus And children are harmful.
Reporters learned from relevant departments, "plastic disposable tableware general technical requirements" has been implemented since December last year, of which the plastic tableware for microwave ovens were specifically required to indicate the product name, type, material, manufacturer Or trademark, lot number, production date and so on. Such as product claims can be used microwave heating, should also be marked with the use of temperature, microwave use time, such as marked "microwave oven output power of 2 kilowatts, the use of time of 1 minute."
In addition, if the product is not heat-resistant water, does not apply to microwave ovens, can not touch the oil and other requirements, should also be marked. Last year, the first thermoplastic plastic tableware standard "Thermoplastic Plastic Tableware Local Technical Specification" formulated by Guangzhou Quality Supervision, Inspection and Research Institute was also implemented on August 1, but after a long time, reporters in Beijing several large Medium-sized supermarket survey situation, in strict accordance with the standard labeling and instructions of microwave oven dedicated lunch box rare, there are some products simply labeled "microwave oven," the words, there are some products even without any labeling and instructions , Consumers do not understand this too.
Look carefully and use caution labels
According to the technical person in charge of a microwave oven manufacturers, microwave heating food is best to use special utensils, the ordinary pattern with a colorful pattern of the best use of the dishes. The current pattern with a bowl of glaze sub-glaze and underglaze color. Generally smooth surface of the utensils on the glaze can be used for microwave heating, while the rough surface of the underglaze bowl and other general lead content is high, should not be used for a long time heating food. In use, if the glaze found a slight sticky state at high temperatures, it should be abandoned. Where metal and enamel containers must not be used in microwave ovens, porcelain with gold edge can not be used for high temperature heating. Some of these vessels will damage the microwave oven, and some particularly hot after heating, and some high temperature cracking will occur, it is very dangerous.
In addition, the industry pointed out that when consumers buy the most important thing is to look at product labeling. Select microwave oven food containers should be cautious, try to buy large formal brand-name products, reject inferior ceramics; first look at the purchase of plastic tableware signs are complete, and pay attention to the product is in the manual, product labeling and other important position marked "microwave oven" The words.