Experts interpret the deep-seated reasons of "Imitation of porcelain ware
Recently, the relevant media disclosed that some enterprises in the production of melamine tableware, in order to reduce costs, mixed with urea-formaldehyde resin in the raw materials, in the case of heating or in the case of strong acid, strong alkali, will release formaldehyde, there is a safety hazard.
The Beijing Municipal Administration of Industry and Commerce has issued the "Notice on Conducting the Inspection of Melamine Plastic Tableware Lunch Box Products", which requires the inspection of the melamine tableware lunch boxes sold by commercial enterprises. The General Administration of Quality Supervision, Inspection and Quarantine also began to analyze and verify the safety of related products. The melamine tableware industry faces a “retrofit”.
What is the reason for the “melamine tableware storm”? How should relevant departments strengthen supervision? Our reporter interviewed Dong Jinshi, executive vice president and secretary general of the International Food Packaging Association.
Standard vulnerability workshop production
Causes the presence of urea-formaldehyde resin in melamine tableware
What is the reason for these products to be green in such a long time and in such a wide area? How are these problem products tested by relevant state departments?
Dong Jinshi analyzed that the reason why urea-formaldehyde resin is flooded in melamine tableware is related to many factors.
First, standard vulnerabilities and missing. These problem products use the problematic tableware produced by the state's expressly banned use of harmful materials, but they have passed the test of relevant standards and are sold in the market. The fundamental reason is that the unscrupulous enterprise has drilled the national standard and does not require the detection of urea-formaldehyde resin project. Empty. Just like China's food safety supervision system, the government's supervision of tableware is often end-of-line supervision, mainly to check products. However, the "Sanitary Standard for Melamine Moldings for Food Packaging" does not require the detection of urea-formaldehyde resins. Therefore, urea-formaldehyde resins are like melamine in milk powder. They are "popular" in melamine tableware, but the government departments are unable to find them.
According to the formal business, because the country explicitly prohibits the use of urea-formaldehyde resin as a raw material for melamine tableware, there is currently no requirement for the detection of urea-formaldehyde resin in the national standard. In the interview with the media, the person in charge of a household products company in Taizhou, who was found to have problems, said directly: "The product reports submitted by the quality supervision department are all qualified."
Dong Jinshi further pointed out that the current "Sanitary Standard for Melamine Moldings for Food Packaging" (GB9690-1988) has not been revised for 20 years and is relatively backward. For example, some inferior melamine tableware may release melamine under certain conditions, such as contact with food, so that the mass of the substance released under certain conditions is called migration, and the existing national standards do not require testing. The amount of migration of melamine.
It is reported that the second revision of the melamine tableware drafted after more than a year has been reported to the Ministry of Health. The draft of the new standard mainly modifies the old standard in four aspects: mandatory inspection of melamine migration; it is required to indicate on the melamine tableware that “the heating is prohibited in the microwave oven” and “melamine for food”; the formaldehyde precipitation limit is from the original 30 mg / liter is further strict to 15 mg / liter; the use of urea-formaldehyde resin is expressly prohibited. However, there is still controversy about whether it is necessary to forcibly detect urea-formaldehyde resins. Because the detection of urea-formaldehyde resin requires the use of equipment such as nuclear magnetic resonance, the inspection equipment of government departments has not yet popularized the instrument.
Secondly, Dong Jinshi pointed out that at present, only 10%-20% of the enterprises producing melamine tableware in China are large enterprises with qualification guarantees. The rest are small and medium-sized enterprises, black workshops or enterprises with backward technology, and the production is not standardized.
Because urea-formaldehyde resin is cheaper than melamine resin, the former is about 4,000 yuan per ton, and the latter is about 14,000 yuan per ton. The use of urea-formaldehyde resin has become a means for non-standard enterprises to reduce costs. According to the regulations of the General Administration of Quality Supervision, Inspection and Quarantine, starting from January 1, 2008, food packaging container manufacturers must obtain production licenses to produce, but as of December 16, only 23 of the country's nearly 1,000 melamine tableware manufacturers have obtained Production License.
Experts call for a long-term mechanism for food safety regulation
Food is the material basis for human survival and development. It not only has nutritional value, but also should be safe. Food safety has two meanings in China. One refers to the food security of the state or society, that is, whether there is enough food supply; the second is the public health problem of the toxic and harmful substances in food affecting human health. What we usually call food safety means that the cultivation, breeding, processing, packaging, storage, transportation, sales, consumption and other activities of food (food) should comply with national mandatory standards and requirements, and there is no toxic that may harm or threaten human health. Hazardous substances, causing consumers to die or endanger the hidden dangers of consumers and their offspring. Food safety includes both production safety and operational safety; both real-life and future safety; both food safety and packaging material safety. Dong Jinshi appealed that while we are paying close attention to food safety, we must also attach importance to the packaging safety of food, establish a safety concept of “food packaging equivalent food”, and add a lock to food safety!
How to strengthen food packaging safety? Dong Jinshi believes that this involves not only the problem of quality management of food safety, but also the construction of a long-term effective food safety system. It will be a long-term task to ensure the safety of food and related products through sound policies, improved standards and improved testing techniques.
It is necessary to build a long-term mechanism with Chinese characteristics, product quality and food safety supervision in line with local conditions. In particular, it is necessary to reform the quality supervision system, change functions, absorb the lessons of terminal management that cannot guarantee food safety supervision, realize the advancement of the barriers, strengthen the supervision of raw materials, production formulas and production processes, and prevent the occurrence of “imitation porcelain” Tableware storms are similar to the occurrence of events. Only by making heavy penalties for those who violate the law, letting them taste the bitterness rather than the sweetness, can make them fearful, and can fundamentally regulate the food industry and guarantee the quality of food and related products.
Related links: Some commercially available melamine tableware containing urea
The melamine tableware is also called melamine tableware and melamine dish. The real melamine tableware is made of melamine resin powder heated and pressed, and has excellent solvent resistance. The surface of the product is flat, non-toxic, tasteless and resistant to falling. It is widely used in tableware, daily necessities, etc., because it automatically extinguishes arcs and other characteristics.
Because of the high price of melamine (melamine) tableware produced by using pure melamine raw materials, some unscrupulous enterprises use low-cost non-food packaging urea-formaldehyde resin instead of high-priced food packaging melamine resin processing melamine (melamine) tableware .
In order to clarify the truth, the International Food Packaging Association research team contacted Professor Zhang Junying of the Bonding Materials and In-situ Curing Laboratory of Beijing University of Chemical Technology to analyze the samples by NMR at the Analytical Testing Center of Beijing University of Chemical Technology. Through the hydrogen spectrum obtained by the experiment, effective information such as chemical shift, coupling constant and integral curve are obtained. Through this information, the position of protons on the carbon can be judged, and the chemical shifts of the nuclei in different groups appear in specific regions. The characteristics determine the type of functional group in the molecule of the compound.
Since the melamine resin differs from the group contained in the urea-formaldehyde resin, their chemical shifts in the hydrogen spectrum are also in different regions, that is, the absorption peak of the functional group contained in the urea-formaldehyde resin appears near 159 ppm, and the functional group contained in the melamine resin absorbs. The peak appeared at around 165 ppm, and it was thus judged whether or not the urea-formaldehyde resin was contained in the polymer.
Urea-formaldehyde resin is obtained by polycondensation of urea and formaldehyde solution under alkali or acid catalysis. Crosslinking occurs during processing to form an insoluble and infusible thermosetting resin product. The cured urea-formaldehyde resin is lighter than phenolic resin, is translucent, resistant to weak acid and weak alkali, has good insulation performance, excellent wear resistance and low price, but it is easy to decompose in case of strong acid and alkali, and has poor weather resistance. Since the urea-formaldehyde resin is hydrolyzed to release formaldehyde gas and the more water, the stronger the acidity, the higher the temperature, the degree of hydrolysis is about severe, and the more formaldehyde gas is released, the use of urea-formaldehyde resin to make tableware is harmful to the human body.
It is well known that formaldehyde (HCHO) is a colorless, irritating and water-soluble gas that acts to coagulate proteins, and its 35%-40% aqueous solution is commonly known as formalin. Formaldehyde is a highly toxic substance, and formaldehyde ranks second in the priority control list of toxic chemicals in China. The World Health Organization has determined that formaldehyde is a carcinogen! The greatest danger to humans is that it is accompanied by a long cycle of human beings and is constantly released. Long-term exposure to low doses of formaldehyde can cause chronic respiratory diseases, resulting in nasopharyngeal cancer, colon cancer, brain tumors, menstrual disorders, nuclear mutations in the nucleus, and even lead to pregnancy syndrome, causing neonatal chromosomal abnormalities, leukemia. Among all contacts, children and pregnant women are particularly sensitive to formaldehyde and the harm is even greater.